This document discusses Down syndrome, which is caused by trisomy 21 resulting in an extra copy of chromosome 21. It presents in 1 in 800-1000 births and risk increases with maternal age. Clinical features include intellectual disability, flat facial features, congenital heart defects, and other physical signs. Management involves genetic counseling of parents on the condition, recurrence risks, and options for antenatal testing and diagnosis. Down syndrome results in lifelong intellectual and developmental disability and medical issues, though early support services can help maximize quality of life.

1. GENETIC DISORDERS AND PRACTICAL
IMPLICATION OF GENETICS IN NURSING
Mrs ARIFA TN
I year M.Sc Nursing, MIMS CON

2. INTRODUCTION
Human is a one of the Almighty’s complex creation. Humans are
made up of trillions of cells and these cells holds the DNA which is
composed of hereditary material. Information stored on DNA is
transferred from one generation to another. Which transfers unique
features from parents to the next generation and so on.
Sometimes DNA has error in its information which cause
different problems like genetic diseases. And these genetic
disorders if transferred to the next generation could be an incurable
disease

3. GENETIC DISORDER
 A genetic disorder or a genetic disease is a condition which is
caused by the error in someone’s DNA. And these errors in a DNA
can be of different type, either single base mutation, single gene
or multiple gene or it can involve the addition or subtraction of
entire chromosome causing the genetic disease.

4. CLASSIFICATION OF GENETIC DISORDERS
 Genetic disorders due to traditional modes of inheritance.
Mendelian disorders: (Single gene)
a. Autosomal dominant (AD)
b. Autosomal recessive (AR)
c. X-linked recessive (XLR)
d. X-linked dominant (XLD)

5. CLASSIFICATION OF GENETIC DISORDERS
 Chromosomal disorders:
a. Numerical abnormalities
b. Structural abnormalities
Multifactorial disorders
Somatic cell mutations

6.  Genetic disorders due to non-traditional modes of inheritance.
1. Mosaicism
2. Genomic imprinting
3. Uniparental disomy (UPD)
4. Inheritance of unstable mutations
5. Cytoplasmic/mitochondrial inheritance

7. GENETIC DISORDERS DUE TO TRADITIONAL
MODES OF INHERITANCE.

8. MENDELIAN (SINGLE GENE) DISORDERS
When a certain gene is known to cause a disease, it is a single
gene disorder or a Mendelian disorder or monogenetic
inheritance.
 Disorders caused by a defect in a single gene follow the
patterns of inheritance described by Mendel. Risks within an
affected family are usually high and are calculated by knowing
the mode of inheritance and details of the family pedigree.

9. MENDELIAN (SINGLE GENE) DISORDERS
Some examples of monogenetic disorders include:
cystic fibrosis, sickle cell anemia, Marfan syndrome,
Huntington's disease, and hemochromatosis.

10. AUTOSOMAL DOMINANT DISORDERS
 Generally, the autosomal dominant mutations caused faults in the
synthesis of structural or non-enzyme proteins.
 These disorders manifest even if only one of the alleles of the
normal gene is affected

11. AUTOSOMAL DOMINANT DISORDERS
 Examples of this type of disorder are:
Huntington's disease, neurofibromatosis type 1,
neurofibromatosis type 2, Marfan syndrome, hereditary
nonpolyposis colorectal cancer, and hereditary multiple
exostoses

13. AUTOSOMAL RECESSIVE DISORDERS
 Autosomal recessive disorders manifest only in homozygous states,
i.e. both the alleles are mutant genes.
 Generally autosomal recessive mutations affect synthesis of enzyme
proteins, leading to inborn error of metabolism.
 Examples of this type of disorder are:
cystic fibrosis, sickle-cell disease, thalassemia, Tay-Sachs disease,
Niemann-Pick disease, spinal muscular atrophy, and Roberts syndrome.

15. X-LINKED RECESSIVE DISORDERS
 Males have an X and shorter Y chromosome. There may be no
corresponding locus or mutant allele of the X chromosome on the
shorter Y chromosome. The mutant recessive gene on X
chromosome, therefore expresses as a clinical disorder in male
child.
 In X-linked recessive conditions only males are affected as there
is no corresponding allele. All his daughters will be carriers as they
receive abnormal X from father.

16. X-LINKED RECESSIVE DISORDERS
 X-linked recessive conditions include: the serious diseases
hemophilia A, Duchenne muscular dystrophy, and Lesch-
Nyhan syndrome, as well as common and less serious conditions
such as male pattern baldness and red-green color blindness.
X-linked recessive conditions can sometimes manifest in females
due to skewed X-inactivation or monosomy X (Turner syndrome)

18. X-LINKED DOMINANT DISORDERS
 These disorders manifest even in XX females as it is a dominant
gene. The gene is transmitted in families in the same way as X-
linked recessive genes, giving rise to an excess of affected
females.
 In some disorders the condition is lethal in hemizygous males. In
this case there will be fewer males than expected in the family, all
of whom will be healthy, and an excess of females, half of whom
will be affected

19.  There is no male to male transmission in this pattern of inheritance
 Examples of XLD disorders:
Incontinentia pigmenti, orofaciodigital syndrome,
hypophosphatemic familial vitamin D resistant rickets.

21. CHROMOSOMAL DISORDERS
 Chromosomal disorders are another type of genetic disorders
which are caused due to an error at chromosomal level. Due to
addition or subtraction of entire gene from the chromosome or
because of structural changes in the chromosomes
 Down syndrome, for example, is caused by an extra copy of
chromosome 21 (called trisomy 21), although no individual gene
on the chromosome is abnormal

22.  Prader-Willi syndrome, on the other hand, is caused by the
absence or non-expression of a group of genes on chromosome
15.
 A specific form of blood cancer (chronic myeloid leukemia, CML)
may be caused by a chromosomal translocation, in which portions
of two chromosomes (chromosomes 9 and 22) are exchanged

23. Chromosomal disorders are further organized into two basic types
 Numerical abnormalities :Numerical abnormalities are due to
the missing of one of the chromosome from the pair, condition
called monosomy. Another condition called trisomy in which more
than one chromosome is missing.
 Down syndrome is the example of numerical abnormalities in
chromosomes

24.  Structural errors
structural errors are due to the change in the structure of a
chromosome. Which can be altered in several ways.
 Deletions: A portion of the chromosome is missing or deleted.
 Duplications: A portion of the chromosome is duplicated, resulting in
extra genetic material.
 Translocations: A portion of one chromosome is transferred to
another chromosome. There are two main types of translocation. In
a reciprocal translocation, segments from two different
chromosomes have been exchanged. In a Robertsonian
translocation, an entire chromosome has attached to another at the
centromere.

25.  Inversions: A portion of the chromosome has broken off, turned
upside down, and reattached. As a result, the genetic material is
inverted.
 Rings: A portion of a chromosome has broken off and formed a
circle or ring. This can happen with or without loss of genetic
material
Most of the chromosomal disorders occur at conception level
when egg and sperm conceived which is why these kinds of
abnormalities occur at every cell level. And it can be transferred to
the next generation.

26. MULTIFACTORIAL DISORDERS
 Inheritance and expression of a phenotype being determined by
multiple gene at different loci and the effects of the genes are
cumulative, with each gene contributing a small amount to the final
expressed phenotype aided by certain environmental factors.
 Examples: schizophrenia, asthma, cleft lip and palate, coronary
heart disease, hypertension, neural tube defects, diabetes and
dislocation of hip.

27. SOMATIC CELL MUTATIONS
 Some cancers can be inherited as simple Mendelian traits, with
clear patterns of transmission, this is the exception rather than the
rule. Even though most cancers involve quite substantial changes
in the genetic material, such mutations are somatic and there is no
risk to further generations

28. SOMATIC CELL MUTATIONS
 Somatic mutation, genetic alteration acquired by a cell that can be
passed to the progeny of the mutated cell in the course of cell
division. Somatic mutations differ from germ line mutations, which
are inherited genetic alterations that occur in the germ cells (i.e.,
sperm and eggs). Somatic mutations are frequently caused by
environmental factors, such as exposure to ultraviolet radiation or
to certain chemicals

29. SOMATIC CELL MUTATIONS
 Somatic mutations may occur in any cell division from the first
cleavage of the fertilized egg to the cell divisions that replace cells
in a senile individual. The mutation affects all cells descended from
the mutated cell

31. GENETIC DISORDERS DUE TO NON-TRADITIONAL
MODES OF INHERITANCE.

32. MOSAICISM
 Somatic mosaicism is the term used to describe the finding of two
different cell lines in one individual that are derived from a single
zygote (i.e. coming from a single egg and sperm). It occurs as a
post zygotic event (after fertilization).
 The mosaicism may be for (i) chromosomal abnormalities or (ii)
single gene mutations.

33.  Chromosomal Mosaicism- It has been recognized in cultured
lymphocytes of patients with chromosomal aneuploidy syndromes.
Eg: Down syndrome, Turner syndrome
 Single Gene Mosaicism- Somatic mosaicism for single gene
mutations. Eg: McCune-Albright syndrome (MAS)

34.  Germline Mosaicism-It refers to the presence of mosaicism in the
germ cells found in the gonads. The mosaicism may be for
chromosomal abnormality or a single gene mutation. Germ line
mosaicism has been found in Duchenne muscular dystrophy, chronic
granulomatous disease and osteogenesis imperfecta.

36. GENOMIC IMPRINTING
 During the last decade, several new mechanisms of genetic
inheritances have been recognized and one such is genomic
imprinting.
 Genomic imprinting means that the expression of gene depends
on the parent of origin. The genes are modified during
gametogenesis and as a result either inactivated or activated.
 Maternal and paternal sets of genes are not functionally equal.
Some genes are preferentially expressed from maternal or
paternal side.

37.  Eg: Prader-Willi syndrome and Angelman syndrome are disorders
due to deletion in the chromosome 15q 11-13 region.
 If the deletion is inherited from father, Prader-Willi syndrome will
result and if the deletion is inherited from the mother it results in
Angelman syndrome.
 Prader-Willi syndrome- microdeletion on paternal side or
inheritance of both copies from maternal side. Angelman syndrome-
microdeletion on maternal side or inheritance of both copies from
paternal side

40. UNIPARENTAL DISOMY
 An individual inherits a pair of homologous chromosomes, one
from the father and the other from the mother. Recent DNA
technology has revealed that an individual may inherit both
homologous chromosomes from only one of his parents and this
situation is called as uniparental disomy.
 Eg: Beckwith-Wiedemann syndrome

42. UNSTABLE MUTATION (TRIPLE NUCLEOTIDE REPEATS)
 Some genetic conditions are caused by an unusual genetic
change- an expansion of a segment of DNA that contains a repeat
of 3 nucleotides (triple repeat), such as CAGCAGCAG
 As the gene is passed from parent to offspring, the number of
triplet repeats may increase. In this way, the condition may worsen
(be more severe) or have an earlier onset from generation to
generation (genetic anticipation)
 Eg: Fragile X syndrome, Myotonic muscular dystrophy, Huntington
disease

44. MITOCHONDRIAL INHERITANCE
 Mitochondria are intracellular organelles which are ubiquitous in
eukaryotes and are essential for survival
 Mitochondrial disorders may be caused by defects of nuclear DNA
or mtDNA.
 Nuclear DNA defects may be inherited in an autosomal recessive
or dominant manner

45. MITOCHONDRIAL INHERITANCE
 Mitochondrial DNA defects are transmitted by maternal
inheritance. Mitochondrial DNA point mutations and duplications
may be transmitted down the maternal line.
 Since egg cells, but not sperm cells keep their mitochondria during
fertilization, mitochondrial DNA is always inherited from the female
parent

46. MITOCHONDRIAL INHERITANCE
 Examples of mitochondrial disease include: an eye disease called
Leber's hereditary optic atrophy; a type of epilepsy called MERRF
which stands for myoclonus epilepsy with Ragged Red Fibers; and
a form of dementia called MELAS for mitochondrial
encephalopathy, lactic acidosis and stroke-like episodes.

48. LIST OF SOME GENETIC DISORDERS

52. COMMON GENETIC DISORDERS

53. DOWN SYNDROME (TRISOMY 21)
The most common chromosomal disorder (1:800 to 1:1000
newborns).
 The chromosome number 21 is present in triplicate.
 The origin of the extra chromosome maybe maternal or paternal.
 The risk in the newborns is directly proportional to the age of the
mother. As maternal age increases, the risk also increases. Risk is
very high if maternal age is more than 35 yrs

54. DOWN SYNDROME (TRISOMY 21)
 BASIC DEFECTS:-
a) Non-disjunction – 95% - All cells carry three copies of
chromosome 21
b) Translocation – 4%- Translocation of the extra chromosome 21 to
another chromosome. (chromososme 14 or 22)
c) Mosaicism – 1%- Some cells have normal number of
chromosomes and some carries extra chromosome

56. CLINICAL FEATURES
General
 Mental retardation;
 Hypotonia
Cranio-facies
 Flat occiput;
 Oblique palpebral fissures;
 Epicanthic folds;
 Speckled iris (Brushfield spots);
 Protruding tongue;
 Prominent malformed ears;
 Flat nasal bridge
Thorax
 Congenital heart disease, mainly
septal defect, especially of the
endocardial cushion
CLINICAL FEATURES

57. Abdomen and pelvis
 Decreased acetabular and iliac angles;
 Small penis;
 Cryptorchidism
Hands and feet
 Simian crease;
 Short, broad hands;
 Hypoplasia of middle phalanx of 5th
finger (clinodactyly)
 Gap between 1st and 2nd toes (sandal
gap)
 Kennedy crease
Other features observed with
significant frequency
 High-arched palate;
 Strabismus;
 Broad, short neck;
 Small teeth;
 Furrowed tongue;
 Intestinal atresia;
 Imperforate anus;
 Hirschsprung disease
 Risk for hypothyroidism and leukemia

58. Common complications
1) Death due to congenital heart disease and lower respiratory tract infection.
2) Chronic rhinitis.
3) Conjunctivitis.
4) Periodontal disease.
Risk of recurrence
 Non-disjunction – subsequent chances are 1% in addition to the risk of highmaternal
age.
 Mosaicism – if one child is Down, the subsequent chances is 1%.
 Translocation – subsequent chances are 5% to 100%

59. MANAGEMENT
A) Principle of genetic counselling
 To be given after confirmation of diagnosis.
 Both the parents should be present.
 Given by a team of physician, geneticist and psychiatrist.
 A number of sittings are required.

60. B) Counselling
 Explain the parents about the disease, that the child is going to be mentally retarded,
require special schooling.
 Explain about congenital heart diseases, other abnormalities, social performances is
good-smiles, laughs (lovable moron), interested in music and mimicry
 Counselling about the recurrence risk.
C) Antenatal diagnosis
1) Initial screening with
 Maternal serum markers
 PAPP-A and beta HCG (human chorionic gonadotropin - in 1st trimester)
 Serum alpha fetoprotein (AFP), HCG, unconjugated estriol and inhibin A - in 2nd
trimester

61.  Fetal ultrasonography
 1st trimester – nuchal translucency and nasal bone
 2nd trimester - Increased nuchal fold thickness, short femur and humerus length and
duodenal atresia.
2) Prenatal karyotyping
 Chorionic villous sampling – can be carried out between 10 to 12 weeks of pregnancy
(transcervical or transabdominal).
 Amniocentesis – on 16 to 18 weeks
 Cordocentesis – after 18 weeks
 The risk of fetal loss after CVS is 3-4%, after cordocentesis is 3% and after amniocentesis is
0.5-1 %.

63. TURNER SYNDROME (45 X0 OR GONADAL DYSGENESIS)
 Karyotype: 45 X0
 Incidence: 1:3000 newborns
 Genetics: Female with only one X chromosome

64. CLINICAL FEATURES:
 The disorders maybe recognizable at birth - *lymphedema of the dorsum of
hands & feet, loose skin folds at the nape of neck.
 Short stature, short neck with webbing, low posterior hairline
 Face - Anomalous ears, prominent narrow & high arched palate, small
mandible & epicanthal fold
 Broad shield-like chest & widely spaced nipples
 Increased carrying angle at elbow
 Knee anomalies
 Short 4th metacarpals & metatarsals

65. CLINICAL FEATURES:
 At puberty, sexual maturation fails to occur...primary amenorrhea and they will
be infertile females
 Adult height <145 cm
 Pigmented naevi, keloid, abnormal nails, puffiness of dorsum of fingers
 Mentally normal
 Associated congenital defects are common
 Kidney – horse-shoe kidney, double or cleft renal pelvis
 Heart – coarctation of aorta
 Ears – perceptive hearing defect
 Congenital lymphedema – usually recedes in early infancy*

67. HORMONE PROFILE
 Low plasma estradiol
 High plasma LH & FSH concentration
DIAGNOSIS
 Hormone profile
 Karyotyping
 Prenatal diagnosis – amniocentesis, cordocentesis, chorionic villus sampling

68. MANAGEMENT
 Height monitoring, cardiac evaluation, BP measurement, ECHO at baseline &
every year is recommended.
 Growth hormone therapy to improve height 0.375mg/kg/week daily SC
 Ovarian hormone replacement – to elicit increase in height and development
of secondary sex characteristics. 100μg/kg/day ETHINYL ESTRADIOL at 12-
13 yrs of age.
 Dose is gradually increased over 2-3 yrs& subsequently cyclical therapy
estrogen-progesterone combination is started

69. MANAGEMENT
 Sometimes a Y chromosome may be present in patients with Turner
syndrome. In that case Prophylactic GONADECTOMY is recommended – due
to chances of developing gonadoblastoma
 Counselling regarding behavioural problem due to short stature, amenorrhea
and sterility.
 Evaluation of thyroid dysfunction. TSH measurement every year.
 Regular audiometry
 Evaluation of renal malformation by USG

70. KLINFELTER’S SYNDROME
 Karyotype: 47XXY
 Incidence: 1:500-1000 newborns
 Genetics : Male with extra X chromosome

71. CLINICAL FEATURES
 Delayed/ incomplete puberty. It is difficult to identify this syndrome in prepubertal males.
 Gynaecomastia
 Reduced facial and body hair
 Infertility
 Crytorchidism
 Hypospadias
 Micropenis
 Abnormally tall
 High risk of breast cancer and SLE
 Learning disabilities and delayed speech and language development

73. TREATMENT
 Early identification and anticipatory guidance are extremely helpful; Treatment should address 3
major issues of the disease: hypogonadism, gynecomastia, and psychosocial problems.
1. Androgen therapy
 Testosterone replacement should begin at puberty, around age 12 years, and the dose should
increase until it is sufficient to maintain age-appropriate serum concentrations of testosterone,
estradiol, follicle-stimulating hormone (FSH), and luteinizing hormone (LH).
 Androgen therapy is used to correct androgen deficiency, to develop secondary sexual
characters, and to improve psychosocial status. Regular testosterone injections can promote
strength and facial hair growth; build a more muscular body type; increase sexual desire;
enlarge the testes; improve mood, self-image, and behavior;

74. TREATMENT
Speech and behavioral therapy
 A multidisciplinary team approach can assist in improving speech impairments, academic
difficulties, and other psychosocial and behavioral problems.
 In children, early speech and language therapy is particularly helpful in developing skills in the
understanding and production of more complex language.
 Males with Klinefelter syndrome should receive a comprehensive psychoeducational
evaluation to assess their areas of strengths and weaknesses. The information obtained from
these evaluations may be helpful in planning appropriate resources and classroom placement

75. TREATMENT
Physical and occupational therapy
 Physical therapy should be recommended in boys with hypotonia or delayed gross motor
skills that may affect muscle tone, balance, and coordination. Occupational therapy is advised
in boys with motordisabilities
Treatment for infertility:
 Men with Klinefelter syndrome were considered infertile until 1996.Nowadays artificial
reproductive technologies are available like Intracytoplasmic Sperm Injection and IVF More
than 60 children have been born worldwide after successful intracytoplasmicsperm injection
(ICSI) in couples in which the male partner has Klinefelter syndrome.

76. EDWARD’S SYNDROME(TRISOMY 18)
 Incidence : 1 in 3000 live births.
 It is the second most common autosomal trisomy among live births.
 Genetics : Presence of three chromosome in 18 instead of the normal two.

77. CLINICAL FEATURES
 Failure to thrive
 Severe developmental delay
 Hypertonia-extreme rigidity
 Head-Microcephaly, dolichocephaly, prominent occiput, strawberry-shaped
head
 Face-Small eyes, upturned nose, small mouth, small jaw( micrognathia) ,low
set and malformed ear
 Hands
 Clenched hands with index finger overlapping middle finger, little finger overlapping ring finger, due to
flexion deformity of fingers
 Underdeveloped nails -Simple dermal arches on nearly all digits
 Very short fourth digits with a single crease

78.  Thorax : Shield-like chest, short sternum
 Abdomen: Inguinal or umbilical hernia, part of the intestinal tract is outside the stomach
(omphalocele)
 Small pelvis
 Rocker bottom feet , prominent calcaneum, short dorsiflexed of first toe
 Skin mottling
 Heart
 Congenital Heart Defects
 Ventricular SeptalDefect(90%)
 Patent DuctusArteriosus(70%)
 Atrial SeptalDefect(20%)
 Valvular regurgitation may occur at multiple sites
 Coarctation of aorta

79. CLINICAL FEATURES
 Eesophageal atresia
 Kidney anomalies
 Undescended testis
 Vertebral abnomalies
 Arthrogryposis (Stiff joint)
 Psychomotor retardation

80. INVESTIGATION:
To confirm diagnosis
 Karyotyping
To diagnose complication
 Complete blood count
 Urine examination
 Chest X-ray
 X-ray of bones, cranium,vertebralcolumn,pelvis
 ECHO and ECG for congenital heart defects
 Ultrasonography of abdomen

81. TREATMENT
 Resuscitation is often required at birth. Baby is kept in intensive care unit. -
Poor sucking ability so nasogastric tube is needed
 Surgery may be needed to correct defects or abnormalities, eg. Heart defects,
omphalocele, hernia
 Access to programs and services as required eg.physical therapy, speech
therapy, educational support, social, vocational, and medical services.
 Genetic counseling and joining a support group is recommended

82. COMPLICATIONS:
 Spontaneous abortion
 Stillbirth
 Apnoea
 Congestive heart failure
 Early infant death
 Failure to thrive
 Mental retardation
PROGNOSIS:
Prognosis is very bad due to life-threatening medical complications. Mortality rate is high
justbefore and after the baby born. The median survival is about 3 months.

83. TRISOMY 13 / PATAU SYNDROME
 Patau syndrome is a syndrome caused by a chromosomal abnormality, in
which some or all of the cells of the body contain extra genetic material from
chromosome 13. The extra genetic material disrupts normal development,
causing multiple and complex organ defects.
 Incidence: 1:5000 births.

85. CLINICAL FEATURES
 Developmental and physical retardation
 Microcephaly with sloping forehead
 Holoprosencephaly
 Microphthalmia
 Coloboma of iris
 Retinal dysplasia
 Cataract
 Malformation of ear
 Cleft lip/ cleft palate
 Capillary hemangioma
 Polydactyly
 Congenital heart diseases- VSD, PDA, ASD

87. Diagnosis
 Immediately obtain conventional cytogenic diagnosis
 Abnormal antenatal ulatasound findings including birth defects and growth restriction
 Fluorescent in situ hybridization (FISH) on interphase cells
 Cardiac evauation
Management
 At previtable gestational ages : MTP should be discussed
 Surgical interventions in patau syndrome are generally withheld for the first few months of life
because of the high mortality rates of babies with this condition

88. INBORN ERRORS OF METABOLISM
 Inborn errors of metabolism are conditions due to genetic defects related to synthesis,
metabolism, transportation or storage of biochemical compounds
Causes
 Most are inherited in an autosomal manner
 Some are through X -linked
 They can also arise out of spontaneous mutations

89. CLASSIFICATION
Traditional classification include
1.Disorders of carbohydrate metabolism, aminoacid metabolism, organic acid metabolism,
lysosomal storage diseases
In recent decades many more diseases have discovered
2.Disorders of porphyrin metabolism Eg: acute intermittent porphyria
3. Disorders of purine or pyrimidine metabolism Eg: lesch- nyhan syndrome
4. Disorders of steroid metabolism Eg: congenital adrenal hyperplasia
5. Disorders of mitochondrial function Eg: Kearns- Sayre syndrome
6. Disorders of peroxisomal function Eg: Zelweger syndrome

90. SYSTEM WISE CLINICAL MANIFESTATIONS
General
 Growth failiure
 Failiure to thrive
 Weight loss
 Unusual facial
features
 Congenital
malformations
Genital
 Ambigous genitalia
 Delayed puberty
 Precocious puberty
Neurological
 Developmental
delay
 Seizures
 Dementia
 Encephalopathy
 Stroke
Sensory
 Deafness
 Blindness
 Pain agnosia
Dermatology
 Skin rash
 Abnormal
pigmentation
 Lack of
pigmentation
 Excessive hair
growth
 Lumps and bumps
Hematological
 Immunodeficiency
 Thrombocytopenia
 Anemia
 Enlarged lymph
nodes
 Gastro intestinal
 Recurrent vomiting
 Diarrhea
 Abdominal pain
 Hepatic
 Hepatomegaly
 Jaundice
 Liver failure

91. Renal
 Excessive urination
 Renal failure
 Dehydration
 Edema
Cardiovascular
 Hypotension
 Heart failure
 Enlarged heart
 Hypertension
 Myocardial
Infarction
Respiratory
 Hyperventilation
 Respiratory failure
Musculoskeletal
 Joint pain
 Muscle weakness
 Cramps
Endocrinal
 Hypothyroidism
 Adrenal insufficiency
 Hypogonadism
 Diabetes mellitus
Behavioural
 Abnormal behavior
 Depression
 Psychosis
Dental
 Dental abnormalities
 Others
 Many forms of cancer

92. DIAGNOSIS
Many diagnostic tests are used for screening
 Ferric chloride test … turns colours in reaction to various abnormal metabolites in urine
 Ninhydrin paper chromatography ( detects abnormal aminoacid patterns)
 Guthrie bacterial inhibition assay
 Quantitative plasma aminoacids, quantitative urine aminoacids
 Urine organic acids by mass spectrometry
 Specific diagnostic tests ( or focused screening for a small set of disorders)
 Tissue biopsy or necropsy: liver, muscle, brain, bone marrow
 Skin biopsy and fibroblast cultivation for specific enzyme testing
 Specific DNA testing

93. MANAGEMENT
 Dietary restriction eg: reduction of dietary protein remains a mainstay of treatment for phenylketonuria
and other aminoacid disorders.
 Dietary supplementation or replacement eg: cornstarch several times a day helps people with glycogen
storage disease from becoming hypoglycemic as quickly
 Vitamins eg: thiamine supplementation benefits several types of lactic acidosis
 Intermediary metabolites, compounds or drugs that facilitate or retard specific metabolic pathways
 Dialysis
 Enzyme replacement
 Gene Therapy
 Bone marrow or organ transplantation
 Treatment of symptoms and complications
 Prenatal diagnosis and avoidance of pregnancy or abortion of an affected fetus

94. PHENYLKETONURIA
 Phenylketonuria is an autosomal recessive genetic disorder characterized by
a deficiency in the autozome phenylalanine hydroxylase (PAH). This enzyme
is necessary to metabolize the amino acid phenylalanine to the aminoacid
tyrosine. When PAH is deficient , phenylalanine accumulates and is converted
into phenylpyruvate (also known as phenylketone), which is detected in the
urine.
Complications
 Left untreated this condition can cause problems with brain development,
leading to progressive mental retardation and seizures

95. CLINICAL MANIFESTATIONS
Early symptoms include
 Albinism
 Musty odour to baby’s sweat and urine (
due to phenyacetate , one of the ketone
produced)
If untreated
 Fail to attain early developmental
milestones
 Develop microcephaly
 Pregressive impairment of cerebral function
In later life
 Hyperactivity
 EEG abnormalities
 Seizure
 Severe learning disabilities
 Hypopigmentation
 Eczema

96. MANAGEMENT
Diagnosis
 HPLC test
 Gothrie test
Treatment
 Diet low in phenyalanine for the ret of his/ her life
 Avoid foods high in phenylalanine such as meat, chicken, fish, nuts, cheese, legumes and
other diary foods
 Starchy foods such as potatoes, bread, pasta and corn must be monitored
 Infants may still be breast fed to provide all of the benefits of breastmilk though the quantity
must be monitored and supplementation will be required Many diet foods and diet soft drinks
that contain the sweetner aspartame consists of two aminoacids: phenylalanine and aspartic
acid

97.  Supplementary infant formulas are used in these patients to provide the aminoacids and other
necessary nutrients that would otherwise be lacking in protein free diet. These can continue in
other forms as the child grows up such as pills, formulas and specially formulated foods.
 Since phenylalanine is necessary for the synthesis of many proteins, it is required but levels
must be strictly controlled, usually being limited to 10 grams of protein. More severe forms of
PKU such as CPKU require patients to be restricted to less than 5. Inaddition tyrosine , which
is normaly derived from phenylalanine, must be supplemented
 The oral administration of tetrahydrobiopterin ( a cofactor in the oxidation of phenylalanine)
can reduce blood levels of the aminoacid in certain patients.
 There are a number of other therapies currently under investigation, including gene therapy
and an injectable form of PAH.

98. PRACTICAL APPLICATION OF GENETIC IN
NURSING

99. PRACTICAL APPLICATION OF GENETIC IN
NURSING
Recent advances in genetic knowledge and technology have impacted all areas of nursing
practices. Application of genetic in nursing is very wide .
 All nurses have role in the delivery of genetic services and management of genetic
information.
 Nurses require genetic knowledge to identify , support , refer , care for persons
 Genetic nursing is practiced in different environment such as maternity , paediatric , medical
surgical nursing and community health nursing

100. MAJOR PRACTICAL APPLICATION OF GENETIC IN NURSING
 Understands genetics basis of disease-
Role of different genes in causation of genetic disorders and defects ,Normal and abmormal cell
devision , good or bad genes for health illness continuum.
 Early and effective diagnosis of genetic disorder
 Contributes towards health promotion with genetic aspects
 Prevention of genetic condition
 Management and care of genetic disorders
 Genetic information and counselling referral services
 Social and ethical issues in genetic

101. CONCLUSION

102. REFERENCE
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BROTHERS MEDICAL PUBLISHERS ;2015.
2. SONISAMTA .TEXTBOOK OF ADVANCED NURSING PRACTICE.NEWDELHI;JAYPEE;2014.
3. BASHEER P,KHAN Y.A CONCISE TEXTBOOK OF ADVANCED NURSING
PRACTICE.BANGALORE;EMMESS;2013
4. BACHMAN JW. GENETIC DISORDERS. INFAMILY MEDICINE 2003 (PP. 141-148). SPRINGER,
NEW YORK, NY
5. FRAZIER L, MEININGER J, LEA DH, BOERWINKLE E. GENETIC DISCOVERIES AND NURSING
IMPLICATIONS FOR COMPLEX DISEASE PREVENTION AND MANAGEMENT. JOURNAL OF
PROFESSIONAL NURSING. 2004 JUL 1;20(4):222-9.