Genetic Science And Its Effects

Genetic Science And Its Effects
genetic disorder that many are unaware of or oblivious to the detrimental effects it can have on
someone. This disease was named after Dr. George Huntington due to his discovery of these weird
movements that were found in patients with this disease (Genetic Science). Approximately one in
thirty thousand people in the United States currently have this disease in the United States (Genetic
Science). For many, that may not be much of a number compared to other cancers and genetic
disorder, but considering the detrimental symptoms that greatly shorten one's life in this disease, it is
a serious problem. In fact, patients with Huntington's have proteins that accumulate in one's brain,
becoming toxic and eventually resulting in cell death ... Show more content on Helpwriting.net ...
For the mass majority of people who contract his disease, these symptoms will begin appearing
when they are between thirty–five to fifty years of age (Porter 783). The early stage of Huntington's
is associated with the motor and movement part of the symptoms. Inconspicuous muscle jerks will
begin, but will be almost unnoticeable, since they can easily be covered up or mistaken for
something insignificant. Yet, as time goes on, they will become more and more obvious, as the
person begins to do things like walk in a puppet–like or tilting way, and having less control over
their hold. They will also begin to blink, grimace, and flick the limbs more often, becoming
thoroughly uncoordinated (Porter 783). Then, their throat muscles will also begin to spasm, making
it difficult for them to speak or swallow (The Gale). Eventually, the harsh and sad reality of this
disease will be that even things like sitting still, speaking, dressing, and eating will become difficult
tasks to accomplish independently (Porter 783). Yet despite all of these impending symptoms, the
changes are unfortunately not bound to just physical changes. Mental changes will also occur,
causing people to be able to become frustrated and irritable as well as excitable more easily (Porter
783). Throughout the years, patients' moods will continue changing drastically, most likely
becoming seriously depressed and even attempting suicide. They
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The Epidemiology Of Huntington's Disease
Huntington'S disease
What is Huntington's disease? how is it diagnosed?
Huntington's Disease (HD) is a genetically inherited, progressive, autosomal dominant, fatal
neurodegenerative disease that's characterized by behavioral difficulties, decline of cognitive
abilities, abnormal involuntary movements (chorea), and muscle spasms (dystonia) (1). These
characteristics help diagnose patients with HD, but a genetic test can be done to prove that one has
the disorder. The gene responsible is that which produces the huntingtin protein in chromosome 4;
the defect causes extra repeats of the chemical code (2).
Symptoms, Morbidity and Mortality, incidence
As stated above, those affected with the disorder display signs of neurodegeneration, including

Are Antisense Oligonucleotides and Effective Trearment for...
Introduction The concept of an Antisense oligonucleotide (an ASO) was first introduced by
Stephenson and Zamecnik, who used an antisense nucleotide to stop viral replication in cell
culture[1]. The effectiveness of ASOs as treatments has already been seen in other disease, such as
Vitravene (or Fomivirsen), which was the first ASO made publicly available, and is used to treat
cytomegalovirus retinitis, as well as Isis 3521 which when given to lung cancer patients in addition
to combination chemotherapy has been seen to raise life expectancy by as much as 50%[2]. From
these past successes, many have hypothesised that they might make an effective treatment for
Huntington's disease (HD) as well, which currently we are only able to treat the ... Show more
content on Helpwriting.net ...
From the effectiveness of the application of antisense oligonucleotides in other disease of a similar
pathology, it stands to reason that ASOs should be a viable therapeutic for treating Huntington's
disease. Issues with the use of ASOs as therapeutics While a promising target, the use of antisense
oligonucleotides in treating Huntington's disease has not been without its issues. The first issue that
using ASOs in the treatment of HD that we face is the lack of stability found in ASOs in their
normal state. Without modification, most ASOs are broken down immediately upon entrance into
the host body by intracellular endo and exonucleases. This is a huge fault in therapeutics, as if the
ASO is broken down it will be unable to produce its desired effects, but also as one of the by–
products created by its degradation– dNMP2 mononucleotides– is cytotoxic and so could cause
further potential harm to the patient [2]. This problem has been resolved in many cases through
modifications to the structure of the ASOs. One such modification is it's methylation to form a
methylphosphonate backbone, which has a far superior stability to the original ASO, but has itself
faced issues due to the reduction in charge that occurs after methylation, which reduces the ASOs
stability in the body. Another, far more widely used modification in

Verkerk's FMR1 Genetic Disorder
INTRODUCTION
Verkerk discovered the fragile X mental retardation 1 (FMR1) gene in 1991, in individuals with a
chromosomal instability at the 5'–untranslated exon 1 on the long arm of the X chromosome
(Xq27.3), a location closely related to autoimmunity (Verkerk et al., 1991). The position of this
unstable region in a non–coding exon is a typical trait shared by other nucleotide repeat disorders,
even though the reason of such association remains unknown. At present, more than 30 genetic
disorders, often and curiously presenting with neurological impairment, share an altered number of
repeated nucleotides, albeit the FMR1 gene mutation is undoubtedly the most studied. A CGG triplet
repeat expansion characterizes the FMR1 gene mutation. Although belonging to the genetic
conditions ... Show more content on Helpwriting.net ...
It is widely acknowledged that the X chromosome instability at Xq27.3 originates by a dynamic
mutation with a variable expansion of a trinucleotide (CGG) repeat (Budworth and McMurray,
2013). This gene instability seems to rely in the loss of AGG triplet inserts commonly identified
every 9–10 CGG triplets (Dombrowski et al., 2002). These AGG triplet repeats, accountable for
alleles stability of the CGG expansion, may deeply influence the risk of full mutation, as in
individuals carrying the same number of CGG repeats, such risk shows a 10–fold increase. The
AGG inserts may then influence the remodelling phenomena essential for the modulation of the
neurosignals, as they limit the further expansion of the CGG repeats (Eichler et al., 1994).
Microsatellites and triplet repeats probably contribute, during the adaptive evolution, to the species
diversity, thus representing a central mutational event (Kashi and King,

Essay A Brief Discussion of Genetic Diseases
Since the discovery in 1928 via the Griffith experiment (an experiment dealing with bacterial
transformation) that DNA carried genetic information, many important discoveries have been made
regarding the human genome and its extent in the determination of phenotypic traits. Not least of
these is the discovery and study of genetic disorders, or diseases caused by abnormalities within the
genes. Disorders of this nature can be caused by a variety of factors. Some diseases such as
Huntington's disease must be inherited, while others, such as some cancers, can be the result of
environmental factors slowly mutating the genome over time. Still others can result from random
errors in normal DNA replication. Typically, genetic ... Show more content on Helpwriting.net ...
In more advanced cases, cancerous cells can exhibit metastasis, a process in which the cells spread
to multiple other parts of the body. At this point in the disease, survival of the patient becomes much
less likely. Cancer can affect any part of the body, but it is more common in areas of the body that
are regularly exposed to outside influences that may lead to mutations, resulting in cancers such as
lung, skin, and lymphatic cancers (National Cancer Institute). Cancer is believed to be caused
primarily by environmental factors. This would include, for example, UV light from the sun, which
can cause dimerization of thymine nucleotides ultimately leading to mutations causing skin cancer.
Similarly, mutagens in cigarette smoke are involved in causing lung cancer. However, more recent
studies show that predisposition to cancer is inheritable. The logic to this lies in the mechanism in
which cancer develops. For cancer to develop, a single cell in the body must be mutated so that it
undergoes continuous and uncontrollable cell division without the ability to exhibit apoptosis (i.e.
programmed cell death for the good of the organism). In order to gain these abilities, a series of
genes must mutate simultaneously within the cell. First, a class of genes called oncogenes must be
turned on to express themselves at high levels. Activation causes the loss of apoptosis ability and
accelerates cell growth and cell division. In addition, another class of

Protein Link Essay
Genetic and Protein link
Although approximately 42 dominant SCAs have been identified only 20 have been genetically
identified. Most of the identified SCAs share a common mutation: SCA1 SCA2, SCA 3, SCA6,
SCA7, SCA8, SCA12, SCA17 have all been linked to the same CAG trinucleotide repeat but in
different varying chromosomes and loci. These are also known as polyglutamine (Poly–Q) diseases.
Poly–Q proteins are extended proteins formed by an expansion of the mRNA that coded for the
amino acid chain during translation. The Polyglutamine–expansion disease family encompasses at
least nine heritable disorders, including Huntington disease (HD) and the spinocerebellar ataxias
SCA1, SCA2, SCA3, SCA6, SCA7 and SCA17. 11 Normally the proteins formed ... Show more
RNA toxicity is based in the three–dimensional structure of mRNA and the creation of hairpin
loops. Normally mRNA is completely linear but when the strand of mRNA is abnormally long it
increases the likelihood of folding to occur. Long CAG repeats match C–G with an A–A Match.
Figure 1 is several examples of mismatch formation that can result in RNA toxicity. As Figure 1
displays not all hairpin loop formations are singular. In some cases, multiple loops can form
depending on the exaggerated length of the mutant mRNA. In a healthy individual, the ATXN1 gene
has CAT (histidine) triplets imbedded between long sections of CAG. Loss of these CAT triplets
leads to changes in the RNA and the protein level and is associated with disease development.13 In
normal individuals, these interspersed CAT triplets destabilize the hairpin structure, which is then
stabilized in patients.13 Polyglutamine aggregates are caused by conformational changes in proteins
and eventually protein toxicity. In extended proteins, there is a long Poly–Q tail from the protein and
since the function of proteins is based on the three–dimensional shape created by the interactions
between amino acids. The long tail can manipulate other or its own protein structure possibly
resulting in toxicity. Transcriptional dysregulation in the brain has been implicated as a common
generic molecular mechanism underlying pathogenesis in a myriad of spinocerebellar ataxias.14
Most of the Poly–Q

Huntington Disease Research Paper
An estimated three to seven out of every hundred thousand people of European ancestry are affected
by Huntington Disease. People of Japanese, Chinese, and Asian descendant populations appear to
have a less common rate of Huntington Disease(1).
Huntington Disease is a progressive brain disorder which causes uncontrolled movements, loss of
thinking ability, and emotional problems. There are two types of Huntington Disease, Adult–onset
and Juvenile. Adult–onset is the most common form of Huntington Disease and those diagnosed live
about fifteen to twenty years after beginning symptoms. The early signs and symptoms include
depression, small involuntary movements, irritability, poor coordination, difficulty in making
decisions, and difficulty retaining new information. As it progresses, the involuntary movements
become more pronounced causing issue with walking, speaking, thinking, reasoning abilities, and
personality changes (1).
Juvenile–onset is the least common form of Huntington Disease and begins in childhood and
adolescence. Those diagnosed live about ten to fifteen years after the first symptoms begin. These ...
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The HTT gene plays an important role in the brain's nerve cells and involves a DNA segment known
as CAG trinucleotide repeat. The CAG repeat is made up of a series of three DNA building blocks
that appear multiple times in a row. A normal repeat of CAG is only 10–35 times within the gene,
however, affected individuals have a 36–120+ repeat. An increase in the CAG size leads to the
production of abnormally long versions the the Huntington Protein. These longer versions are then
cut into smaller and toxic fragments that bind together and accumulate in neurons; this disrupts the
normal functions of these cells. The dysfunctional, and eventual death, of neurons in specific areas
of the brain control the signs and symptoms of Huntington Disease

Causes Of Fragile X Syndrome
Fragile X Syndrome
Fragile X Syndrome is a genetic disorder caused by a disruption in the FMR1 gene and is the most
recurrent inherited form of intellectual disability (Bagni, et al., 2012). It can cause a variety of
mental effects ("Fragile X syndrome", 2017). For these reasons, Fragile X Syndrome has the chance
of being a model of translational neuroscience (Jayaseelan, Tenenbaum, 2012).
General Facts About Fragile X Syndrome
Fragile X Syndrome (FXS) is a trinucleotide repeat expansion disorder where triple expansion is
preventing expansion of the FMR1 gene. (Bagni, et al., 2012; "Fragile X syndrome", 2017)."
Regarding this, Jasaseelan and Tenebaum state that Fragile X syndrome was the first disorder found
to relate to RNA regulation to ... Show more content on Helpwriting.net ...
Tassone, F. Neri, G. et al. "Fragile X syndrome: causes, diagnosis, mechanisms, and therapeutics."
Journal of Clinica l Investigation, vol. 122, no. 12, 2012, p. 4314+. Science in Context,
http://link.galegroup.com/apps/doc/A312510065/SCIC?u=cobb90289&xid=53eeaf73.
Fragile X syndrome. (2016). Funk & Wagnalls New World Encyclopedia, 1p. 1. http://proxygsu–
scob.galileo.usg.edu/login?url=https://search.ebscohost.com/login.aspx?
direct=true&db=funk&AN=FR070350&site=eds–live&scope=site Jayaseelan, S., & Tenenbaum, S.
A. (2012). Signaling pathways of fragile X syndrome. Nature, 492(7429), 359+. Retrieved from
http://link.galegroup.com/apps/doc/A359733151/SCIC?u=cobb90289&xid=6c99b104
Quercia, N., MS, CCGC, CGC, & Alic, M., PhD. (2016). Fragile X Syndrome. In T. Moy & L.
Avery (Eds.), The Gale Encyclopedia of Genetic Disorders (4th ed., Vol. 2, pp. 712–715).
Farmington Hills, MI: Gale. Retrieved from

Velo-Cardio-Facial Syndrome Hypothesis
Argument 1 for "yes": ARVCF is a gene located on chromosome 22. Microdeletion within this gene
causes Velo–Cardio–Facial syndrome (VCFS). Psychosis is common in adults with VCFS, often
fitting the diagnostic criteria for schizophrenia. Hence, ARVCF may be linked to schizophrenia.
Argument 1 for "no": Genetic variations in chromosome 22q11 are unrelated to schizophrenia in
Koreans. Schizophrenic individuals with a certain genetic variation in chromosome 22 can have
family members with the same genetic variation who are not schizophrenic. This indicates that
genes on chromosome 22 are not strongly linked to schizophrenia.
>Evidence Subjects with schizophrenia and normal control subjects were recruited for a study in
which their DNA was collected and sequenced for the ARVCF gene. SNPs in this gene were found
only ... Show more content on Helpwriting.net ...
Three microsatellite markers on chromosome 22q11 were genotyped for each individual. The
analysis showed no links between any of the three markers. In addition, an association study was
performed on unrelated schizophrenic patients and normal control individuals. No association was
found between schizophrenia and the four genes tested on chromosome 22q11.2
Argument 2 for "yes": One of the genes on chromosome 22 is GNB1L. High expression of this gene
is associated with schizophrenia. Argument 2 for "no": In some cases where two or more siblings in
a family have schizophrenia, no links are found on chromosome 22 among the siblings. This
suggests that chromosome 22 does not carry the gene that causes schizophrenia.
>Evidence Frozen brain samples were obtained from Han Chinese individuals. DNA and mRNA
were isolated from these samples and genotyped for the GNB1L region on chromosome 22. mRNA
expression of this gene was examined. It was found that the high–expression allele of GNB1L was
the risk factor related to schizophrenia in the Han Chinese

Huntington's Disease: A Case Study
Huntington's disease (HD) is an inherited disease that leads to the breakdown of nerve cells in the
brain. HD affects a person both physically and mentally. Some symptoms include personality
change, depression, forgetfulness, unsteady gait, involuntary jerking, slurred speech, and difficulty
in swallowing. HD is considered a late on set disorder, because people don't show symptoms until
their 30's or 40's (Mayo Clinic Staff, 2014). HD progressively gets worse and worse and has 3
different stages. The early stage of HD includes changes in coordination, involuntary movements,
difficulty thinking through situations, and a depressed mood. In the middle stage of HD, the person
will struggle more moving, thinking and reasoning will go down hill quickly and problems talking
and swallowing will become worse. The late stage of HD is when it really gets bad, the person
becomes fully reliant on someone else and choking becomes a major issue. The person will not be
able to speak or walk in the late stage. Medications can be taken to help manage symptoms, but
treatments can't stop the mental and physical breakdown of the person. Speech therapy can help
with speech and swallowing and occupational therapy can be helpful in learning to deal with
movement issues. Exercise is also very helpful (Huntington's Disease Society of America, n.d). ...
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These tests are mostly simple and are very certain, because Huntington's disease is a breakdown of
your brain.

The Disease Of The Middle Ages
Rooting back to the middle ages the now commonly known Huntington's disease is the cause of
death in one out of 15000 people around the globe. The disease's existence is documented through
history under many different names depending on the amount of information that was gathered
through the unusual progression of the disease. The disease was referred to as Chorea initially due to
the jerky movements of the patients affected by it. The first thorough description of the disease
surfaced in 1872 as George Huntington whom the disease is named after today presented a detailed
definition of the disease through his first paper. George Huntington was able to accurately detect the
pattern of inheritance of an autosomal dominant disease by examining the combined medical
histories of a family that clearly suffered from the disease through generations. The disease could
not be studied further until the rediscovery of the Mendelian Inheritance in the 20th century that
allowed scientist to look further into the autosomal dominant disease. "Of its hereditary nature.
When either or both the parents have shown manifestations of the disease ..., one or more of the
offspring almost invariably suffer from the disease ... But if by any chance these children go through
life without it, the thread is broken and the grandchildren and great–grandchildren of the original
shakers may rest assured that they are free from the disease." (Huntington) Huntington's Disease is a
hereditary and progressive

Fragile X Disease Essay
Fragile X is a disease which severely influences the everyday lives of those affected by it. It is a
disease which unfortunately limits an individual in several respects. Physical symptoms include an
elongated face with larger than normal ears and feet. Additionally, the individual will have a
difficult time interacting with others due to shyness and trouble with processing faces, thus
encountering behavioral road blocks. Most importantly, the individual may have intellectual
disabilities such as difficulty with memory, all a result of having Fragile X. Fragile X is the most
common single gene which leads to autism and other intellectual disabilities. Fragile X is
transmitted through DNA. Within the DNA, it has been found that the ... Show more content on
Helpwriting.net ...
As previously stated, those with more than 30 repeated trinucleotides of CGG are likely to develop
some form of Fragile X (often referred to as premutation), with those having over 200 repeats
having the full syndrome (also known as a full mutation). All of the repeated trinucleotides are
located within the promotor region of the FMR1 gene. The reason the FMR1 gene produces so little
FMRP is due to a process called methylation. "Methylation is a process which inactivates a gene,
and the larger number of repeats inactivates the gene. When the gene is inactivated, the cell may
make little or none of the needed FMRP." (NICHD 2009). Figure 2: Normal promoter region VS.
Elongated promoter region (NICHD 2009) Intriguingly enough, in certain cases, despite having
200+ CGG trinucleotide repeats within a FMR1 gene, it is still possible to be able to produce FMRP.
One way this can be performed is by being born female. Males are born with an X and Y
chromosome. Females however, are born with two X chromosomes. A female with Fragile X in one
chromosome may not necessarily have Fragile X within the other chromosome. Within the female,
certain cells may choose to activate one of the X chromosomes, and other cells may choose to
activate the other X chromosome. Hence, even though there exists a Fragile X chromosome, not all
cells within the body will use it, thus the production of FMRP is possible using the other normal X
chromosome.

What Is The Cause Of Huntington's Disease
Named after George Huntington, who described it in 1872 as an inherited neurodegenerative
disorder, In 1983 Huntington's disease was the first disease to be molecular mapped to a human
chromosome, ten years later in 1993 scientist were able to identify the gene that is responsible for
causing Huntington's disease.
This illness affects about 30,000 Americans; in addition, another 150,00 are at high risk. A child
with a parent with HD has 50 percent chance to inheriting the disease.
Huntington's disease is caused by a mutation in the gene for a protein called huntingtin. The defect
causes the cytosine, adenine, and guanine (CAG) building blocks of DNA to repeat many more
times than is normal leading to a overproduction of this protein resulting

Fragile X Syndrome: A Case Study
Introduction:
Fragile X syndrome is a trinucleotide repeat disorder caused by the expansion of the unstable CGG
repeat within the fragile X mental retardation 1 (FMR1) gene.
FXS is an X link dominant disease. However, as there are two components to the inheritance of FXS
(inheritance of the fragile X chromosome and whether or not epigenetic silencing of the gene has
occurred in a previous generation) there are some components of its inheritance pattern:
Affected males inherit a fragile X chromosome that had not been silenced in the previous generation
by a cycle of maternal chromosome inactivation and incomplete reactivation.
Father's suffering from Fragile X syndrome will have daughters unaffected by the disease as they do
not inactivate ... Show more content on Helpwriting.net ...
This expansion causes methylation of the CGG region and the upstream CpG island in the FMR1
gene silencing its expression. As a result, little to no FMR1 gene product, fragile X mental
retardation protein (FMRP), is formed and this is what leads to the cognitive impairment in people
with the disorder.
FMRP is expressed throughout the body, especially in the brain, neurons, testes (spermatogonia),
and the ovaries.
FMRP is found attached to ribosomes (both free in cytoplasm and attached to endoplasmic
reticulum), at the bases of dendrites and within dendritic spines. This is indicative that FMRP may
play a role in synaptic function and plasticity.
The association of FMRP with ribosomes is mRNA dependent via large ribonucleoprotein (RNP)
particles. RNP particles contain other proteins including FXR1P, FXR2P, YB–1, CYFIP1, CYF1P2,
NUFIP1 and nucleolin.
FXR proteins are a family of proteins that are related in structure (likely originating from a common
ancestor gene) to FMRP. As a result, they are able to form homotypic and heterotypic interactions
with FMRP. (Willemsen, R., et al. 2004)
FMR1 may go through X inactivation. However, methylation appears

Kennedy's Disease: A Genetic Analysis
Recently, a new mutational mechanism leading to increase in number of CAG repeated triplets in
several human genes responsible for the hereditary disorders was identified [Caskey et al., 1992;
Richards et al., 1992]. The cause of disease is expansion of trinucleotide repeat in the androgen
receptor (AR) gene on X chromosome at the Xq11^12 (La Spada et al. 1991). The principal
pathological manifestation of the SBMA is loss of the motor neurons in spinal cord and the
brainstem (Sobue et al. 1989).
Kennedy's Disease goes by many names that are given following (many are same and just arranged
or spelled by differently):
Kennedy's Syndrome
Kennedy Disease
Spinal Bulbar Muscular Atrophy
Spinal and Bulbar Muscular Atrophy
X–linked Spinal

Huntington's Disease Research Paper
Huntington's disease (HD) is a rare and fatal disease known as a polyglutamine neurodegenerative
disorder effecting only 4–10 per 100,000 people of European decent (Driver–Dunckly et. Al 2007).
This means there is a problem with the trinucleotide that codes for glutamine, cytosine–adenine–
guanine (CAG). In the case of HD there is an extreme overproduction of the CAG repeats in the
protein huntingtin. Accumulation of this mutated form of the protein in neurons causes cell atrophy
which in turn causes the brain to malfunction. The disease was first described by Dr. George
Huntington in 1872, however it wasn't until 1993 that the cause of the disease was actually
discovered (Bertram et. Al 2005).HD is characterized by symptoms effecting the afflicted ... Show
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The dorsal striatum is composed of the caudate nucleus and the putamen. The striatal cells appear to
be the most vulnerable to the inclusion bodies formed by the aggregates of mutant huntingtin. As the
disease progresses and more inclusion bodies are accumulated the striatal cells begin to die at a
faster rate than they are reproduced. The death of these cells cause the striatum to degrade. The
exact mechanisms by which the striatal cells function is disrupted is still being researched, however
it is theorized that the damage to the mitochondria from mutant huntingtin or toxic glutamine
segments is one of the culprits (Turner, et. Al 2010). The basal ganglia allows one to start and stop
movement, controls cognition and comprehension, and also controls mood. The degradation of the
striatum interrupts all of these function which attributes to the clinical manifestations of the disease.
The disease is fatal because eventually the striatum of the basal ganglia becomes so damaged that
the individual can no longer swallow. Mutant huntingtin may also affect certain layers of the
cerebral cortex, the hypothalamus, thalamus, and parts of the cerebellum (Purves et. Al,

Myotonic Dystrophy Research Paper
Myotonic Dystrophy is the most common form of muscular dystrophy. It is a chronic, multi–system
disorder that is characterized by progressive muscle wasting and weakness. Symptoms include;
myotonia (prolonged muscle contractions), the inability to relax certain muscles after use, slurred
speech, temporary locking of jaw, cataracts, abnormalities of the electrical signals that control the
heartbeat, and early balding and infertility in men. There are two major types of myotonic
dystrophy, type 1 and type 2. Many of the symptoms are overlapping, the only differences are type 1
is generally more severe than type 2 and type 1 affects the lower legs, hands, neck and face.
Whereas, type 2 affects the neck, shoulders, elbows, and hips. Myotonic dystrophy ... Show more
This protein may play a role in the communication within cells, especially those of the heart, brain
and skeletal muscles. It is believed that the protein is involved in the communication between cells
and regulates the production and function of important structures inside muscles cells by interacting
with other proteins. The DMPK gene is located on the long arm of chromosome 19 at position 13.3.
It is between base pairs 45,769,708 and 45,782,556 making it 12848 base pairs long. It consists of a
trinucleotide repeat of the nucleotide sequence CTG. Meaning that the nucleotides CTG are
repeated multiple times. In a normal DMPK protein the number of CTG repeats ranges from 5–34.
The mutation that causes myotonic dystrophy is known as trinucleotide repeat expansion, meaning it
increases the number of times CTG is repeated in the gene. People with myotonic dystrophy can
have 50 to 50,000 repeats, the more repeats an individual has the worse their symptoms are. The
increased number of repeats produces an expanded version of mRNA, which then forms clumps
inside the cell that interfere with the production of many other proteins. These clumps prevent
muscle cells and cells in other tissues from functioning

Analysis Of Huntington's Disease
Huntington's disease is an inherited brain disorder that has a broad effect on a person's physical and
mental abilities. Unlike other passed down diseases, signs and symptoms of Huntington's disease
can start at any age but usually show between the age of thirty and forty. The onset of this disorder
may even begin at the age of 20 or even before that and is known as the juvenile Huntington's
disease. Individuals with this disease can only live about 15 to 20 years after signs and symptoms
appear and earlier onset form of this disorder may result in a faster progression. Huntington's
disease is caused by the mispelling in the HTT gene for a huntingtin protein. Involved in the HTT
mutation that causes Hungtington's disease, the CAG trinucleotide ... Show more content on
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Having the ability to make different cells, embryonic stem cells and iPS cells are being used in this
research to generate transplanted medium spiny neurons. In study, the iPS cells could be found in
people who don't carry the disorder's genetic fault and could be used to grow the needed dead nerve
cells in Huntington's disease. But the iPS cells generated from people without the disorder have a
very high percent chance of not being suitable for transplantation into affected individuals. Since
that is the challenge, others have proposed a different way to make iPS cells directly from the skin
of the affected ones using gene–editing techniques. Medium spiny neurons then found to grow
healthily from these corrected iPS cells as the nerve cells from people without the disease. Even
though much more study and examination are needed, this approach one day can be a big
achievement that can be used to reverse the course of the

Congenital Adrenal Hyperplasia
Title:
Clinical approach to a case of congenital adrenal hyperplasia (Investigations, management and
complications).
Introduction:
Congenital adrenal hyperplasia is a number of autosomal recessive disorders, it is due to mutations
of enzymes responsible for adrenal steroidogenesis. Deficiency of 21–hydroxylase enzyme is the
most common form of CAH, responsible for about more than 90% of the cases. This limits the
ability of adrenal glands to produce the vital hormones cortisol and aldosterone. The absence of
these hormones causes the body to produce excessive androgen which can cause ambiguous
genitalia in female patients.[]
Aim:
Aim is to determine the efficacy of certain investigations in the diagnosis of CAH, to assess the role
of certain ... Show more content on Helpwriting.net ...
Clitoral pain is associated with clitoral recession and clitorectomy. We may give medications to
prevent more virilization [10].
Good value with using abdominal sonar in congenital adrenal hyperplasia with ambiguous genitalia
to demonstrate the uterus and renal anomalies [11].
CAH is one of the pathological etiologies of Addison's disease rendering infants with CAH more
prone to Addison disease (congenital Addison disease) in comparison to infants with adequate
adrenal function [12].
Steroids therapy is recommended in the case of congenital adrenal hyperplasia, the use of steroids
therapy twice a year After the patient's condition is stabilized [13].
There were no available studies showing:
The value of acetyl salicylic acid in the treatment of CAH.
That the length of repetition of CAG nor GGn is statistically significant modulators of genital
virilization in females with 21OHD[3].
The value of estrogen pills in treatment of an infant with ambiguous genitalia in a case of classical
CAH [6].
Conclusion:
Concerning the investigations studies show a good value for assessment of blood glucose and

galactose level, abdominal sonar and assessment of selective serum rennin but no studies
recommend screening for trinucleotide repeat expansion

Genetic Disease Is An Autosomal Dominant Neurodegenerative...
Genetic diseases are diseases that are passed on from parents to their offspring. An example of a
genetic disease which can be inherited is Huntington Disease. "Huntington Disease is an autosomal
dominant neurodegenerative disorder with midlife onset characterised by psychiatric, cognitive and
motor symptoms"(G. Vonsattel and DiFiglia, 1998). The statistics for HD blah blah blah Like all
genetic diseases, huntington 's disease has a specific inheritance pattern.
Huntington disease is an autosomal disease this means that the defective gene does not occur on one
of the sex chromosomes but instead it occurs on one of the other 22 chromosomes (known as
autosomes). It is a also a dominant disorder so therefore only one copy of the altered gene, passed
on from a parent who has it, is necessary to cause their offspring to inherit the disease. If one of the
parents has the defective gene their offspring will have a 50/50 chance of inheriting that gene. (See
Figure 1).
If the offspring inherits the gene it is guaranteed that they will develop Huntington 's disease at
some point in their life time, the disease does not skip generations. The defective gene is not present
on either of the sex chromosomes resulting in the disease being independent of gender. This means
that male and female offspring will have an equal risk of inheriting the disease. The faulty gene (the
HD gene) that is to blame for the development of huntington 's disease is located on chromosome 4
(See Figure 2), it

Presymptomatic: A Case Study Of Huntington's Disease
Huntington's disease is a chronic and fatal neurological disorder caused by a trinucleotide repeat. It
is caused by a genetic defect on chromosome four that causes a CAG repeat. When the number of
repeats exceeds a certain amount, a neurological disease results. In a normal person, this section of
DNA is repeated 10 to 35 times, but in a person with Huntington's disease it is repeated 36 to 120
times. The disease is genetic and is passed down in families. If one parent has Huntington's disease
offspring have a 50% chance of getting the disease. The average age of onset is 40 years and the
disease progresses over 10 to 25 years. A presymptomatic genetic test is used to identify if a person
has an expanded Huntingtin gene copy. The genetic ... Show more content on Helpwriting.net ...
If the test is positive it removes all hope and introduces the uncertainty of when the symptoms will
appear. This can trigger depression. It has been statistically shown that a person who is diagnosed
with the disease is at a higher risk of committing suicide. Adolescents, specifically teenagers are
scientifically proven to already be more susceptible to depression because of how the brain of an
adolescent processes the same behaviors differently from adults. There is currently no treatment for
Huntington's disease, but there are medications that can slow the progression of the disease.
However, these medications are commonly not used until early or mid–adulthood. If there were a
cure for Huntington's disease genetic testing of adolescents would be encouraged, but there is no
such cure. The medical and psychological benefits of a genetic test will not accrue until adulthood,
therefore genetic testing should be deferred. Genetic testing for Huntington's disease should be
discouraged because genetic testing in children and adolescents outweigh the potential benefits.
Instead parents should wait till a child is old enough to independently make the decision to be tested
and has the mental capacity to deal with anxiety and depression that may come with a positive
result. Although, a person at risk should decide to get tested when they reach adulthood so they are
able to monitor their

Huntington's Disease – Mayo Clinic
Huntington's Disease–Mayo Clinic
Huntington's disease is an inherited disease that causes the progressive breakdown (degeneration) of
nerve cells in the brain. Huntington's disease has a broad impact on a person's functional abilities
and usually results in movement, thinking (cognitive) and psychiatric disorders.
Medications are available to help manage the symptoms of Huntington's disease, but treatments
can't prevent the physical, mental and behavioral decline associated with the condition.
Movement Disorders
The movement disorders associated with Huntington's disease can include both involuntary
movements and impairments in voluntary movements:
Involuntary jerking or writhing movements (chorea)
Muscle problems, such as rigidity or muscle ... Show more content on Helpwriting.net ...
The HTT gene provides instructions for making a protein called huntington. Although the function
of this protein is unknown, it appears to play an important role in nerve cells (neurons) in the brain.
The HTT mutation that causes Huntington disease involves a DNA segment known as a CAG
trinucleotide repeat. This segment is made up of a series of three DNA building blocks (cytosine,
adenine, and guanine) that appear multiple times in a row. Normally, the CAG segment is repeated
10 to 35 times within the gene. In people with Huntington disease, the CAG segment is repeated 36
to more than 120 times. People with 36 to 39 CAG repeats may or may not develop the signs and
symptoms of Huntington disease, while people with 40 or more repeats almost always develop the
disorder.
An increase in the size of the CAG segment leads to the production of an abnormally long version
of the huntington protein. The elongated protein is cut into smaller, toxic fragments that bind
together and accumulate in neurons, disrupting the normal functions of these cells. The dysfunction
and eventual death of neurons in certain areas of the brain underlie the signs and symptoms of
Huntington

Huntington's Disease
Adolescents at risk for Huntington's Disease should undergo predictive genetic testing to maximize
their enjoyment of life as a healthy individual. Although fatal, Huntington's Disease is not an
immediate death sentence. People can usually continue to function normally for many years if the
disease is diagnosed in adolescence. Testing for Huntington's Disease can end uncertainty and allow
adolescents to make informed decisions about the rest of their lives in order to make better use of
the time that they have as a healthy person.
Huntington's Disease is a late–onset fatal genetic disorder that results in the gradual deterioration of
nerve cells in the brain. Typical symptoms include involuntary movements, loss of muscle control,
depression, ... Show more content on Helpwriting.net ...
Since Huntington's Disease is autosomal dominant, there is a 50/50 chance of passing the faulty
gene onto a child (Learning About...). If a woman knows that risk beforehand, she could decide to
adopt a child instead of risking bringing life to a child with a fatal illness. Huntington's Disease has
no cure, which makes it all the more important that adolescents be tested (What Is...). That way,
people can decide if they would be willing to participate in studies or trials to help scientists gather
research for a cure. The more people with currently healthy brains that participate in studies, the
better the quality of research that will be

Symptoms And Treatment Of Huntington 's Disease
Huntington's disease INTRODUCTION & AIM The aim of this project is to discuss the various
components that shape Huntington's disease. The efficiency of this paper will depend heavily on a
brief but, comprehensive examination of past and future research that may offer plausible
suggestions and explanations to the following four subtopics; the history of Huntington's disease,
anticipation and genetic markers of Huntington's disease, symptoms and treatment of Huntington's
disease and finally living with Huntington's disease. This research paper will focus namely on the
above stated categories but, will not be restricted to comprise only of the mentioned fields.
According to the National Institutes of Health, Huntington Disease was first documented in
Venezuela, the gene was identified in the extended family of a woman who first migrated from
Europe in the early 18th century. As outlined by the National Institute of Neurological Disorders and
Stroke (NINDS), Huntington's disease must result from the inheritance of the defective gene
attained from an afflicted parent, which causes the brain cells to atrophy, ultimately resulting in full
acquisition of the disorder; and the progressive failure of the individual's motor and cognitive skills.
The research will explore the mystery that surrounded the disease in the early stages of its
discovery, as people and family members affected sought to keep their infirmity hidden due to fear
of ridicule (Wexler, 2010). In addition to this,

Essay on Understanding Huntington's Disease
Understanding Huntington's Disease
Huntington's disease is an inherited neurodegenerative disorder. It is passed on to children from one
or both parents (though two parents with Huntington's is extraordinarily rare) in an autosomal
dominant manner. This is different from autosomal recessive disorder, which requires two altered
genes (one from each parent) to inherit the disorder.
So if one parent has it, and passes the gene on to a child, that child will develop Huntington's
disease if they live long enough and each of that child's' children will have a 50% chance of
inheriting the gene, and so on and so forth. If you do not have the HD gene you can't pass it on to
your children and if your mate doesn't have it then there is no way ... Show more content on
Helpwriting.net ...
It tends to lessen in the later stages. When the disease occurs in childhood (less than 10% of cases)
Chorea is more severe and may coincide with rigidity or muscle stiffness and movement restriction.
Both chorea and rigidity interfere with coordination and mobility. Changes in mood are not readily
noticeable as they are slow to manifest and can be interpreted as something else (i.e. HD causes
depression but so does our society so this symptom often gets overlooked) Anxiety, irritability, rage,
mania, and psychosis are also common symptoms. Cognition (the mental process characterized by
thinking, learning, and judging) is affected early in the disease and gets worse over time. Individuals
will have problems with math, memory, judgment and verbal fluency. It is very difficult for
someone with HD to learn a new task, especially in the later stages of development. There currently
is neither a cure nor FDA approved medical treatment for Huntington's disease. The life expectancy
is 15 –– 20 years after development begins, and though Huntington's itself doesn't directly kill the
individual, it causes so many functional breakdowns in the body that the person can no longer
perform basic physical operations such as swallowing and as such a common cause of death is
choking or respitory infection.
Biochemistry and Molecular Biology
Huntington disease is caused by the expansion of a

Huntington Disease Outline
What are some of the symptoms of Huntington's Disease?
 Changes in personality
 Mood swings
 Depression
 Impaired judgement
 Involuntary movement
 Unsteady gait
 Problems with speech
 Difficulty swallowing
 Rapid weight loss
Symptoms do not typically manifest until ages 30–50. Works Cited: 1. "Huntington's Disease: Read
About Treatment Options." MedicineNet, www.medicinenet.com/huntington_disease/article.htm. 2.
"What Is Huntington's Disease?" Huntington's Disease Society of America What Is HD,
Huntington's Disease Society of America, hdsa.org/what–is–hd/. 3. "Huntington's Disease." Mayo
Clinic, Mayo Foundation for Medical Education and Research, 13 June 2017,
www.mayoclinic.org/diseases–conditions/huntingtons–disease/symptoms–causes/syc–20356117. 4.
"Huntington Disease – Genetics Home Reference." U.S. National Library of Medicine, National
Institutes of Health, ghr.nlm.nih.gov/condition/huntington–disease. 5. "Huntington's Disease | HD |
MedlinePlus." MedlinePlus Trusted Health Information for You,
medlineplus.gov/huntingtonsdisease.html. ... Show more content on Helpwriting.net ...
See figure 1 for more information on this mutation.
Genetic Counseling
This disease is inherited from parents, and it is dominant, meaning only one copy of the gene is
needed to develop this disorder. It is extremely rare and it affects less than 0.01% of people of
European ancestry. See figure 2 for heredity patterns. Testing
If you want to get tested for Huntington's Disease, a genetic test can be given to see if you carry the
gene before symptoms begin. However, this test does not predict when symptoms will appear and
which ones will come first. If you decide to get tested for HD, you should contact a testing center. A
small blood sample is taken and tested for the defective gene. Samples from family members also at
risk of HD may be required to confirm the diagnosis.

Myotonic Dystrophy : A Disorder That Affects Multiple Systems
Introduction
Myotonic dystrophy (DM) is a disorder that affects multiple systems in the body. The disease is
broken down into two categories, myotonic dystrophy I & II. Myotonic dystrophy can be
responsible for deterioration of smooth and skeletal muscle, central nervous system, endocrine,
cardiac, and ocular systems. Myotonic dystrophy can contrast from mild to severe, and has "been
categorized into three somewhat overlapping phenotypes: mild, classic, and congenital" (Bird et al.,
1999). Myotonic dystrophy is a multisystem disease damaging to the muscles, heart, brain, eyes and
other organs. Myotonia is defined by the stiffness and tightness of the muscles causing some
muscles to stay in the contracted position much longer than ... Show more content on
Helpwriting.net ...
With an abnormal number of repeats the trinucleotide sequence becomes more unstable and disease
symptoms grow to be more visible. Myotonic dystrophy II (DM2) is a mutation of cellular nucleic
acid binding protein (CNBP), or zinc finger protein 9. The functions of both proteins, CNBP and
DMPK are uncertain, however they can be found in multiple organs and tissues in the body,
including the brain, cardiac, and skeletal muscles (Ueada, Ohno & Kobayashi, 2000). Myotonic
dystrophy is located on chromosome 19q13.3 and is a result of an abnormal repeat of the DNA
sequence. According to Mckusick & Hartz (1986) People with DM2 can have from 75 to more than
11,000 CCTG repeats. Both DM1 and DM2 are autosomal dominant inheritable disease, which can
be passed along to offspring if the parent is affected, at a 50% probability. Myotonic dystrophy is
unique from most provided that "disease–causing alleles may expand in length during
gametogenesis, resulting in the transmission of longer trinucleotide repeat alleles that may be
associated with earlier onset and more severe disease than that observed in the parent" (Bird et al.,
1999).
Anatomical
Myotonia is developed by the over expanded trinucleotide creating a toxic mutant RNA sequence.
According to Wheeler, Lueck, Swanson, Dirksen, & Thornton (2007) the mutant RNA is responsible
for the unregulated splicing

Huntington's Disease Research Paper
Discovered in 1872 by George Huntington, Huntington's disease, also known as Huntington's
cholera, is a genetic disease that causes selected nerve cells in the brain to die (Johns Hopkins). This
leads to uncontrolled movements, emotion problems, and decreased cognition. Generally acting as
an adult onset disease, Huntington's disease is commonly seen to begin in one's thirties and forties.
Once the symptoms begin, the patient generally lives fifteen to twenty more years before
succumbing to inevitable death. Huntington's disease is an autosomal dominant disease, meaning
that a child only needs to inherit one copy of the gene from his parent to develop the disorder.
Rarely, an individual can develop the disorder, despite not having a parent carrying the gene.
Discovered in 1993, the HTT gene provides information in synthesizing a protein called huntingtin
(Johns Hopkins). The HTT gene is located on chromosome four. Individuals with Huntington's
disease has mutations in their HTT gene on the CAG repeat sequence. The CAG mutation leads to
abnormally long huntingtin, which cuts into shorter fragments. These toxic fragments will clump
and accumulate in neurons and disrupt their normal function. Eventually, these neurons will die
(NLM). ... Show more content on Helpwriting.net ...
However, anyone with 36 to 39 repeats are at risk for developing Huntington's disease, while those
with 40 or more is highly probable for developing the disorder. As the mutated HTT gene is passed
down from generation, the CAG trinucleotide repeat is lengthened. Generally, the longer the
repeated sequence, the earlier the onset of the disorder. Patients with 40 to 50 repeats generally will
have an adult onset while those with 60 or more will have a juvenile version. Individuals with 27 to
35 repeats are at risk of having children with the disorder, despite not having them disease
themselves

How Are Genes Affecting Huntington's Disease?
Human beings have two copies of genes that provide genetic information to produce Huntington,
which is a protein. The two copies are usually labeled HTT (Hayes & Reichsman, 2009). A portion
of this gene is as a result of a repetitive section referred to as a trinucleotide repeat that changes in
terms of length from one person to the other, as well as between different generations. In case the
repeat section of the gene is present in a gene that is considered healthy, then an active mutation
might lead to an increment in the repeat sections, which might in turn lead to a gene that is defective
(Marks & Neill, 2007). Subsequently, the length of the repeat portion might reach a given level
where it leads to the production of altered and defective proteins ... Show more content on
Helpwriting.net ...
The wide variety of functions of these altered proteins is the main factors that result in pathological
impacts that effectuate the development of biological symptoms that are related to the disorder. The
mutation caused by Huntington disease is usually dominant and thus, has the fully ability to
penetrate different cells within the body. As such, the mutation of the two copies of Huntington
genes leads to the disease (Quarrell, 2008). Other factors that could affect the development of gene–
related conditions, including sex do not affect the process of inheriting Huntington disease.
However, the length of the genetic section and thus, the severity of the disease might be affected by
the sex of the parent who passes on the disease to their children (Hayes & Reichsman, 2009). In
addition, Huntington disease is one of the wide variety of disorders that are caused by trinucleotide
repeat where the repeat section's length changes in such a way that it leads to a larger size than the
normal one (Quarrell, 2008). The Huntington gene is mainly located on the short side of
chromosome 4. Additionally, this gene contains some level of 3 main DNA bases (Hayes &
Reichsman, 2009). As such a variety of

Genetic Testing and The Diagnosis of Genetic Diseases...
Genetic testing is used to determine the risk of a patient or patient's offspring developing genetic
diseases. This is done with DNA sequencing in adults and preimplantation genetic diagnosis (PDG)
on embryos. These methods of genetic testing are effective means of determining the likelihood of
developing diseases such as Huntington's disease, a disease resulting from trinucleotide repeat on
chromosome 4p16.3 that causes uncontrollable muscle movement and decrease in cognitive
function. However, they only determine probability, which isn't an entirely reliable means of
knowing whether or not symptoms will arise.
It is patients' right to opt for genetic testing on their own DNA, although they are accepting a great
risk by doing so. ... Show more content on Helpwriting.net ...
These strands are separated by length using electrophoresis and detected automatically by
computers to be analyzed (Lyons, 2004). Another method of genetic testing is extracting one cell
from an 8–cell embryo and using preimplantation genetic diagnosis (PDG) to determine the
presence of disorder–causing genes (Holt, 2012).
These methods of genetic testing are accurate, as long as the genetic origin of the tested disease is
known (Mahdieh & Rabbani, 2013), but their reliability is harmed by the fact that the results
determine probability of diseases occurring (Holt, 2012). Even though a test accurately determines
the presence of a given mutation, that mutation may only indicate a patient's predisposition to
developing symptoms. Since other genes or environmental factors may play a part in the tested
disease, the results of testing aren't entirely reliable for a conclusion of whether or not a patient will
develop the disease.
One disease that can be tested for using these methods is Huntington's disease, which causes
involuntary spasms and contractions and a decline of coordination and cognitive ability (Online
Mendelian Inheritance in Man [OMIM], 2014). These symptoms occur as a result of a trinucleotide
repeat in the huntingtin gene on chromosome 4p16.3, also known as the HTT gene. The disease is
autosomal dominant, with the completeness of its

Fragile X Syndrome Essay
Research Paper on Fragile X Syndrome
Introduction
Fragile X syndrome is among the common inherited cause of intellectual disability and single cause
of autism. This is caused by the lengthening of the X chromosome and although both male and
female can be affected, males are more prone to be affected than females – with the ratio of
1/4000:1/8000 (1). This is because males have only one X chromosome, while female has two.
Females can be a carrier of this gene defect but their other X chromosome would still be able to
make the protein, whereas male, only possessing one X chromosome would be more affected.
Symptoms of this mutation includes behavioral and learning disabilities, autism disorder, elongated
and narrow face (macrocephaly), macroorchidism ... Show more content on Helpwriting.net ...
This gene contains a CGG trinucleotide repeats in the 5–UTR ranging from 5 to 54 repeats for the
normal population. The 55–200 repeats is defined as premutation because this range is not enough
to cause mental retardation (5). This range were initially thought to have no effect but it is now
known to have the ability to develop a variety of neurological symptoms such as memory loss,
executive function deficit, anxiety and depression, anxiety, and other problems with numerical
processing (4). Also, female premutation carriers have a possibility to develop primary ovarian
insufficiency while elderly preumation carriers have a possibility to develop a progressive
neurodegenerative disorder called fragile X–associated tremor/ataxia syndrome (6). Both of these
premutation disorders displays an incomplete penetrance. A full mutation is when the trinucleotide
repeats expands up to more than 200. This expansion leads to hypermethylation, which then leads to
transcriptional silencing of the gene and inhibiting it from producing its protein – FMRP – which
plays a role in brain development. Figure 1 portrays a simple summarization of the comparison
among the ranges of CGG trinucleotide repeats (in the 5–UTR) of the FMR1

Essay Huntington's Disease
Huntington's Disease Background Huntington's disease is inherited as an autosomal dominant
disease that gives rise to progressive, elective (localized) neural cell death associated with choleric
movements (uncontrollable movements of the arms, legs, and face) and dementia. It is one of the
more common inherited brain disorders. About 25,000 Americans have it and another 60,000 or so
will carry the defective gene and will develop the disorder as they age. Physical deterioration occurs
over a period of 10 to 20 years, usually beginning in a person's 30's or 40's. The gene is dominant
and thus does not skip generations. Having the gene means a 92 percent chance of getting the
disease. The disease is associated with increases in the length ... Show more content on
Helpwriting.net ...
After heating the reaction to 94 degrees C for 4 minutes, 27 cycles of 1 minute at 94 degreesC and 2
minutes at 67 degrees C, tests were performed. The PCR products were settled on 8%
polyacrylamide gels. The mtDNA deletion levels were quantitated relative to the total mtDNA levels
by the dilution–PCR method. When the percentage of the mtDNA deletion relative to total mtDNA
was used as a marker of mtDNA damage, most regions of the brain accrued a very small amount of
mtDNA damage before age 75. Cortical regions accrued 1 to 2% deletion levels between ages 80–
90, and the putamen accrued up to 12% of this deletion after age 80. The study presented evidence
that HD patients have much higher mtDNA deletionlevels than agematched controls in the frontal
and temporal lobes of the cortex. Temporal lobe mtDNA deletion levels were 11 fold higher in HD
patients than in controls, whereas the frontal lobe deletion levels were fivefold higher in HD patients
than in controls. There was no statistically significant difference in the average mtDNA deletion
levels between HD patients and controls in the occipital lobe and the putamen. The increase in
mtDNA deletion levels found in HD frontal and temporal lobes suggests that HD patients have an
increase mtDNA somatic mutation rate. Could the increased rate be from a direct consequence of
the expanded trinucleotide repeat of the HD gene, or is it from an indirect consequence? Whatever
the origin of the deletion, these

Myotonic Dystrophy Type 1 Research Paper
When people think about a mutation or a genetic disorder, they often tend to think about fictional
like characters such as a half beast half man scenario. However, genetic disorders and mutations are
simply just mistakes in the genetic code. These mistakes can be so minor that it has no effect on you
whatsoever, or they can be a major problem. Myotonic dystrophy type 1 is one of those genetic
mistakes that has a huge impact on the way you live your life. Myotonic dystrophy type 1 is a type
of multisystem disorder that cannot be caught, but is genetically inherited. Myotonic dystrophy type
1 has to do with a special gene and chromosomal problem, with very severe, rare symptoms, and it
has a major impact on life.
First of all, what is myotonic ... Show more content on Helpwriting.net ...
The symptoms are also effected by the age of the carrier. If an adult is experiencing muscle
weakness especially in the leg, hand, neck, and face, and myotonia, which is uncontrollable
contraction of muscles, they should be suspected of having DM1. If a newborn has hypotonia, facial
muscle weakness, general weakness, positional malformations, or respiratory insufficiency, it should
also be suspected of having DM1. Many testes are available to be able to determine if you have
DM1. Some tests include electromyography, serum CK concentration, and a muscle biopsy.
Checking allele sizes also help to determine whether or not you are positive for DM1.
Unfortunately, since the disorder is rare, it is very difficult to predict a prognosis on it. "Non–
molecular testing that has been used in the past to establish the diagnosis of DM1 currently has little
role in diagnosis and is primarily used if molecular testing of DMPK does not identify the CTG
repeat expansion and other myopathies are being considered." (Thomas D. Bird).
Living with DM1 usually has a major impact on your life. In some cases, you can be a carrier of
DM1 and not be affected at all by it. But, in the majority of cases, it really puts a damper on life.
"Some people may experience only mild stiffness or cataracts in later life. In the most severe cases,
respiratory and cardiac complications can be life threatening even at an early age. In general, the
younger an individual is when symptoms

Cause And Symptoms Of Huntington's Disease
Huntington's disease/H.D Huntington's disease causes the breakdown of nerve cells in the brain. It
affects the nervous system and is hereditary. As an Autosomal Dominant disorder, it only needs one
copy of a faulty gene to develop the disorder. It has been assessed that Huntington's disease
influences around 10.6 and 13.7 for each 100,000 people in the European society. In the American
society, 1 in 10,000 will have the disease and furthermore approximately 150,000 Americans also
have the 50% chance of developing the illness. It is very common in European descent, however
appears to be uncommon in Asian populations. This report will explain how it is caused, the signs
and symptoms and how it affects an individual, furthermore it will be explaining ... Show more
It is brought on by an anomaly, which causes the CAG trinucleotide to repeat more than normal. The
signs and symptoms are established at the age of 30–40 years old, otherwise if it is under 20–30 of
age, it is called Juvenile Huntington's disease and usually develops faster than normal. It greatly
affects our movement, our thinking and how we behave. Preventing children from being born with
the illness by doing Vitro Fertilization and preimplantation genetic diagnosis. The ongoing research
for treatment using neuronal transplantation to replace the loss of neurons associated with
Huntington's disease is getting developed making us closer to finding out how to cure it. It is a very
fatal illness that results in lots of deaths, that's why it is a necessity that the treatment must be
developed further for future

Fragile X Syndrome Analysis
Fragile X syndrome (FXS) is among the most common cause of inherited intellectual disability in
humans, associated with a range of social, behavioural and cognitive impairments and it is inherited
as an X–linked dominant disorder with reduced penetrance. The primary cause of FXS is the
expansion of a CGG trinucleotide repeat located in the 5' untranslated region (UTR) of the X–linked
FMR1 gene. (Huddleston L.B., Visootsak J., Sherman S.L., 2014) It affects both males and females
with a prevalence of 1 in 4000 males and 1 in 7000 females; however affected females tend to have
a lower degree of cognitive disability and a less severe phenotype, relating to the degree of X–
inactivation on the abnormal chromosome. Male patients with FXS present ... Show more content
on Helpwriting.net ...
The gene can be alternative spliced in exons 12, 14, 15 and 17 resulting in different mRNAs and
protein isoforms. The CGG trinucleotide repeat in the non–coding part of the FMR1 gene is
unstable, thus the repeat length varies among normal population, with normal individuals ranging
from 6–55 repeats. The trinucleotide repeat often becomes unstable during maternal transmission to
the next generation, giving rise to the expansion of the repeat. Individuals with 55–200 CGG repeats
are considered premutation carriers, and in patients with FXS the CGG repeats are above 200
resulting in hypermethylation and therefore silencing of the gene's CpG site in the promoter region
(Willemsen R., 2011). Pietrobono and her team, studied the events prior to the inactivation of the
FMR1 gene and demonstrated that the initial events seem to be histone deacetylation and H3–K9
methylation, followed by DNA methylation and H3–K4 demethylation (Pietrobono, R., Tabolacci,
E., Zalfa, F., 2005). However, work carried out on human embryonic stem cells has proven that
FMR1 inactivation is a result of downregulation of transcription and chromatin modifications, prior
to DNA methylation (Willemsen R.,

Huntington Disease
According to Genetic Science Learning Center, it has been stated that approximately 1 in every
30,000 Americans have been affected with Huntington Disease and is considered one of the most
common brain disorders due to heredity (Genetic Science Learning Center). This disease was
discovered by a 22–year–old American doctor, named George Huntington, in 1872. Huntington
wrote a paper called On Chorea which was published in the Medical and Surgical Reporter, and the
disorder later become known as Huntington Chorea, but is now commonly known as Huntington
Disease (What Is The History of Huntington's Disease?). Huntington disease–like Syndrome (HDL)
is a condition that resembles a lot like Huntington disease (HD) (Huntington disease–like
Syndrome). ... Show more content on Helpwriting.net ...
The specific function of this protein is unknown, but researchers have discovered roles in several
processes, which include the transportation of copper into cells and protect brain cells from injuries.
Studies have shown a role for PrP in the form of synapsis, which is the junction in between neurons
where communication of cell–to–cell occurs. HDL1 has been identified as the type of mutation in
PRNP which causes the signs and symptoms of HDL Syndrome. The PRNP mutation involves a
segment of DNA called an octapeptide repeat that provides the instructions to make eight amino
acids that form to make a fragment called a peptide. The octapeptide typically repeats five times in
PRNP. For the people who have HDL1, the segment repeats eleven to thirteen times. The increase in
size of the octapeptide leads to abnormally long version of PrP. It's not clear how the abnormal
protein destroys and damages neurons, which is why it leads to the features of HDL1 (Huntington
disease–like

Cracking Your Genetic Code: A Review of Genetic Testing
Cracking Your Genetic Code: A Review of Genetic Testing In Gattaca, the plot focuses on the
ethics, the risks, and the emotional impact of genetic testing in the nearby future. The film was
released in the 90s; yet in the present, the film does not give the impression of science fiction.
Today, genetic testing is prevalent in many aspects of the scientific community. This paper will
describe genetic testing, its purpose, diagnostic techniques that use genetic testing, relating
Huntington's disease to genetic testing, and the pros and cons of genetic testing.
Genetic testing
Description of genetic testing
By using identified gene mutations that are known to cause diseases, asymptomatic individuals are
able to discover if they are at risk ... Show more content on Helpwriting.net ...
Dr. Howard Jacob, a geneticist sequenced Andrew's genome; nevertheless, they were no closer to a
diagnosis (Holt, 2012).
Genetic testing techniques used on adults
Confirmation of Mutated genes. When performed on adults, genetic tests can confirm or deny the
presence of mutated genes in the patient's genome. As previously mentioned, certain gene mutations
are associated with diseases. Once the adult is tested and has a diagnosis, treatment may be
administered. Before genetic testing was readily available, these patients would have to wait for the
symptoms to develop in order to be diagnosed. Specifically, the technique of using recombinant
DNA technology is used to identify various genetic abnormalities (Samen, 1996). Testing methods
that examine genetic abnormalities can be at the protein or chromosomal level. Tay–Sachs disease is
tested at the protein level using studies of enzymatic activity. In the biochemical assay test for Tay–
Sachs, an artificial substrate that will fluoresce when converted to product is covalently linked to the
normal substrate. If individuals are affected with Tay–Sachs, the product will not fluoresce because
the enzyme is not functional. At the chromosomal level, RFLP analysis, DNA sequencing, In situ
hybridization, karyotyping and DNA microarrays can be used. Specifically, karyotyping is a visual
representation of the chromosome's structure and number.
In the NOVA documentary, Ms. Moser's grandfather was suffering from the Huntington's

Kennedy 's Disease : An Incurable Neuromuscular Disorder
Kennedy's Disease is an Incurable Neuromuscular Disorder.
What is Kennedy's Disease? Kennedy's disease is an inherited neurodegenerative disorder that
affects both the spinal and bulbar neurons. KD is a lower motor neuron disorder because it interrupts
the transmission of nerve cell signals in the brain and spinal cord. This interruption affects the spinal
and bulbar neurons causing the major symptoms muscle atrophy, weakness, contraction
fasciulations, and bulbar weakness. KD is the first of the neurodegenerative disease for which the
molecular basis was discovered to be the expansion of a trinucleotide CAG repeat in the causative
gene (Banno, 2012, p.313). The disease is inherited from an impaired x gene. Since KD is a
recessive X– linked gene it primarily affects males. Females are rarely affected because they have
two X chromosomes and are usually just carriers of the defective gene. The carriers of the gene are
usually asymptotic but occasionally can develop mid symptoms. (Cell and Tissue Research, 2012, p.
13)
KD is a very rare disorder, the prevalence thought to be 2 per 100,000 people according to the Cell
and Tissue Research article. It is thought that KD is often misdiagnosis as amyotrophic lateral
sclerosis (ALS). The first case ever recorded of KD came from a patient who was previously
diagnosis with ALS and wanted a seconded opinion. The onset for KD is usually midlife, the range
being from 30–60 years of age. The onset is often preceded by non–specific

The Genetic Factors of Learning Disabilities Essay
The National Institute of Neurologic Disorders defines learning disorders as a; condition that either
prevents or significantly hinders somebody from learning basic skills or information at the same rate
as most people of the same age. It is important to note that this does not mean that the individual has
less intelligence; it means that their brain or body is wired in a way that hinders or prevents
development of a certain tasks. Many people often confuse learning disabilities with mental
retardation but while both words describe similar conditions, the term learning disability and
learning disorder are used to describe conditions that affect development in certain cognitive areas
in otherwise healthy developed individuals. Millions of ... Show more content on Helpwriting.net ...
This is a very real problem and one in which educators of today and tomorrow will have to face day
in and day out.
The roots of learning disabilities have been debated for ages. There is a general consensus that both
genetics and environment play hand in hand in learning and general temperament formation but the
extant of each is debatable. This led me to my central question of what extent has current genetic
research proved regarding the role of genes in the development of learning disorders. I am interested
in what genetically linked disorders are most prevalent in school aged children and plan to detail the
signs and symptoms of the three most prevalent disorders and the current believe about their causes
at molecular level. The first learning disorder that I would like to discuss is Fragile X syndrome.
Fragile X, often called Martin–Bell syndrome for it's the man who discovered it is a trinucleotide
repeat disorder that is found on the sex chromosome X. Fragile X was discovered by Bell in 1943
after he examined a family in which all the boys showed signs of mental retardation. He discovered
that the boys X chromosome he found that the long arm had become thin and fragile looking.
Fragile X affects the genders separately due to its location on a sex linked chromosome. The
disorder affects 1 in every 3600 males but only 1 in 4000–6000 females. (World Health
Organization) As true with other sex–linked

Genetic Science And Its Effects

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Genetic Science And Its Effects