Genomics is the study of the structure and action of the genome, i.e. the sum total of genetic material present in an organism. Genetics is the study of heredity and of the mechanisms by which genetic factors are transmitted from one generation to the next.
2. What is Genomics?
Genomics is an area within genetics that concerns the
sequencing and analysis of an organism genome.
It involves the study of all the genes at the DNA, mRNA, and
proteome level as well as the cellular or tissue level.
By definition, it can be defined as “A discipline in genetics that
applies recombinant DNA, DNA sequencing methods and
bioinformatics to sequence, assemble and analyze the structure
and function of genomes.”
Major Goals: The main goal of the genomics is to;
Sequence the entire genome by cutting it into small,
manageable pieces(fragments). Then assemble the entire
genome from the pieces or fragments.
Understand how gene expression take place.
4. By unravelling the mystery of the genome, researchers are
better able to study diseases.
THE HUMAN GENOME PROJECT:
The Human Genome Project, an
unprecedented international cooperative effort among
scientists, was officially launched in 1990. As its name
suggests, the purpose of this project was to sequence the entire
human genome, a goal which it achieved some 15 years later.
For the medical scientific community, this map of our genome
is of great importance. It helps to identify the genes responsible
for certain diseases and broadens our understanding of the
workings of the human body, particularly the relationships
among genes, proteins and diseases.
How genomics Contribute to Your Health?
5. Genome based testing/Genetic testing:
It is also known as “Presymptomatic” and
“predictive” testing. Genetic testing is a
type of medical test that identifies
changes in chromosomes, genes, or
proteins. The results of a genetic test can
confirm or rule out a suspected genetic
condition or help determine a person's
chance of developing or passing on a
genetic disorder.
Genetic testing, also known as DNA
testing, is used to identify changes in DNA
sequence or chromosome structure.
Genetic testing can also include
measuring the results of genetic changes,
such as RNA analysis as an output of
gene expression, or through biochemical
analysis to measure specific protein
output.
6. Why would we conduct genetic testing?
Reason:
Finding genetic disease in unborn child.
Finding out if people carrying genes for a disease and
might pass it on to their child.
Screening embryos for disease.
Testing for genetic disease in adult before they cause
symptoms.
Making a diagnosis in a person who has disease
symptoms.
Figuring out the type or dose of the medicine that is
best for certain person.
8. Applications of Genomics in Healthcare:
1- Newborn screening:
Newborn screening is a public health program designed to screen
infants shortly after birth for a list of conditions that are treatable
but not clinically evident in newborn period.
Goal:
The goal of newborn screening is early detection of children at
increased risk for selected metabolic or genetic diseases so that
medical treatment can be promptly initiated to avert metabolic crises
and prevent irreversible neurological and developmental sequelae.
Criteria for newborn screening:
Disorder produce irreversible damage before onset of
symptoms.
Treatment is effective if begun.
Natural history of disorder is known.
10. 2-Genomic and Personalized Medicine:
Genomic Medicine:
An emerging medical
discipline that uses genetic
information to customize a
patient’s health maintenance and
treatment plan.
Personalized medicine:
The concept of using genomic
along with an individual patient’s
other molecular, biologic, and
physiologic information, along
with knowledge of individual's
environment, to customize
treatment plans to maintain health,
assist in early diagnosis and
treatment of disease, and enhance
longevity.
12. 3- Gene discovery and diagnosis of rare monogenic
disorders:
Many novel genomic techniques like Next-Generation DNA
Sequencing (NGS) and genotyping arrays open new avenues in
the elucidation of genetic defects causing monogenic disorders.
They will not only speed up disease gene identification but will
enable us to systematically tackle previously intractable
monogenic disorders.
These are mainly disorders not amenable to classic linkage
analysis, for example, due to insufficient family size. Most
monogenic diseases are caused by exotic mutations or splice-
site mutations changing the amino acid sequence of the affected
gene.
14. Other Applications of Genomics in
Healthcare:
Pharmacogenetic and targeted therapy:
Genetic information may be used to predict whether a person will
respond to a particular drug, how well they will respond to that drug and
whether they are likely to get any side effects from the use of a specific
drug. This allows their treating team to make individualized decisions
about the right drug treatment. In some cases, such as cancer, we can
identify the genetic drivers of disease and then give drugs which
specifically target that pathway. This is known as targeted therapy.
Predict and prevent diseases:
By knowing which genes predispose people to particular conditions,
doctors will be able to predict which people are likely to suffer from a
particular disease and offer a preventive course of action, which may
involve medical treatment or lifestyle changes. Furthermore, cures could
be found for genetic diseases like cystic fibrosis or sickle cell anaemia.
15. Continued…
Prenatal diagnosis and testing:
Genetic diseases are often devastating and may cause
significant disability and even death in childhood. Prenatal
diagnosis of genetic diseases allows parents to make
decisions about whether to continue with the pregnancy or to
allow early diagnosis and possible treatment in uteri or at
birth. Whilst previous approaches to prenatal diagnosis could
put the pregnancy at risk, new methods using genomic
technology can look directly at the DNA of the fetus from a
maternal blood test, without increasing the risk of miscarriage
- this is known as non-invasive prenatal testing. The use
of NGS and array technology in prenatal samples is also on
the increase to improve diagnostic yields in a pregnancy.
16. Improve forensic science:
Genetic fingerprinting helps to match a suspect to the
biological material found at a crime scene. In the
future it could be possible to figure out what a
suspect looks like from DNA found at a crime scene
e.g. their eye, hair and skin colour.
.
Continued…
17. Limitations:
Increased stress:
People could be diagnosed with illnesses that they are
susceptible to develop in the future and spend their life
worrying about it even before they get it.
Geneism:
People with genetic problems could be under pressure
not to have children as a threat of passing on their faulty
genes onto the next generation.
18. The last two decades have seen unprecedented
investment in life sciences in UK. Advanced
technologies are now available to sequenced the entire
genome at a cost of a few thousand pounds in as little
as 24 hours, and it is envisaged that this cost will fall
considerably over the next few year. More recently the
Government has signaled its confidence in the power
of genomics science to produced major health benefits
for the population through its investment in the
100,000 genomics projects.
Future Goals of Genomics in Human Health: