Genetic counseling involves evaluating a family's medical history and genetic test results to help them understand inherited disorders and make decisions. Genetic tests analyze blood or tissue samples to identify genes for disorders. Those who may benefit from genetic counseling have a family history of genetic disorders, birth defects, inherited cancers, intellectual disabilities, or recurrent miscarriages. Genetic counseling provides advice on the risks of inherited conditions being passed down and helps with decisions around prenatal testing, treatment, and family planning.

2. Genetic counseling
 It is the process of evaluating family history & medical
records, ordering genetic tests, evaluating the
results of this investigation & helping parents
understand & reach decisions about what to do
next.
 Genetic test are done by analyzing small
samples of blood or body tissues. They determine
whether you or your partner or your baby carry
genes for certain inherited disorders.

3. WHO NEEDS GENETIC COUNSELLING ?
Those who can benefit from genetic counselling include
those who have a history of:
A known genetic disorders e.g. Cystic Fibrosis,
Hemophilia, Down’s syndrome
Birth defects e.g. Spina Bifida, Cleft Lip and Palate,
Congenital heart disease, club foot
Inherited Cancers e.g. Breast and Bowel Cancers
Intellectual disability
Hearing or visual disability
Infertility or multiple miscarriages or infant deaths
Genetic defects occurring frequently in special ethnic and
rational groups e.g. Tay-Sachs disease, Sickle cell
Anemia, Thalassemia.

4. Genetic counselling deals with the problem of giving advice to
families having, or likely to have, children with genetic disorders.
 Causation of human diseases
 Genetic
 Inborn errors of metabolism.
e.g.Phenylketonuria,Galactosemia,Duchenne muscular dystrophy
 Rarer, simple Mendelian inheritance. High risk of recurrence
 Genetic & Environmental
 Pyloric stenosis, Club-foot, Congenital dislocation of hip, Diabetes
mellitus
 Commoner, Multifactorial. Low risk of recurrence

5. Genetic counselling refers to the giving of
scientific advice under following circumstances
1. Risk of recurrence of a hereditary disease in a family.
2. Risk attending the progeny from consanguineous
marriages.
3. Genetic basis in cases of abnormal sexual
development, infertility, recurrent abortion & congenital
malformations.
4. Problem of child adoption.
5. Cases of disputed paternity.
6. Risks of acquiring common diseases.
7. Detection of carrier.

6. Risk of recurrence of a hereditary disease in a
family
 Determining the risk:
 Autosomal dominant
disorder(Brachydactyly, Achondroplasia): risk of
recurrence is 50% - 100%
 Autosomal recessive(Albinism,Phenylketonuria):
chances of affected child is 1 in 4.
 X-linked
disorder(Haemophilia,G6PDdeficiency, Partial colour
blindness):
In male – male progeny – nil; female progeny-
100%.
In female – male progeny -50%; female progeny-
50%.

7. Sporadic case of hereditary abnormality:
when normal parents have child with a rare congenital abnormality; the following
must be considered to calculate the risk of same abnormality to future children.
1. Rule out the effect of teratogenic agent.
2. Find out possibility of new mutation in the gametes.
3. In autosomal recessive disorder,(Phenylketonuria) the parents of the affected
child may be related consanguinously.
4. Known X- linked recessive disorder(Colour blindness)- distinction should made
from an autosomal recessive disorder.
5. Rule out Down’s syndrome, 13 trisomy syndrome, 18 trisomy syndrome & cri du
chat syndrome. When anomalies involves more than one system, karyotyping
should be done to find out if any translocation.
During genetic counselling , the phenomenon of genetic heterogeneity should
be kept in mind.

8. Problem of child adoption
 Determining the risk of inherited disorders in child.
 The main difficulties are encountered when there is a
family history of disease, which is not recognisable
clinically or biochemically in the earlier years of
child’s life e.g. Marfan’s syndrome, Huntington’s
chorea.

9. Cases of disputed paternity.
 Paternity could not be proved with certainty, but it
can be disproved without doubt.
 Paternity can be often disproved on the basis of
blood groups of child & putative father.

10. Risks of acquiring common diseases
 Some of the common conditions such as cleft lip- palate,idiopathic epilepsy,
pyloric stenosis, spina bifida, early onset of diabetes mellitus etc. have no
simple mode of inheritance.some are heterogenous having number of
etiologically different disorders. Others due to effect of many genes or
environment. In such conditions only empiric risks of recurrence can be given.
 An Empiric risk is defined as the probability of occurrence of a specified event
based upon prior experience and observations rather than on prediction by a
general theory.
 It is calculated by estimating the frequency of the condition in the relatives of
the affected persons.
 In multifactorial disorders, the rate of recurrence in first degree relatives is
equal to the sqare root of the prevalence in the general population

11. Antenatal diagnosis of genetic disease
 Procedures- Transabdominal amniocentesis .
Cytological & biochemical study of amniotic fluid
detects gross anomaly. Carried out at about 16 wks
of gestation.
 Radiography
 Ultrasonography- to determine viability of
fetus, gestational age, multiple gestations, placental
& fetal positions & gross fetal malformations.
 Fetoscopy.
 Placentocentesis.

12. Treatment of genetic disease
 Replacement of deficient enzyme or protein
 Drugs
 Viral therapy
 Prevention –avoiding harmful drugs.
 Surgical removal of diseased tissue.
 Transplantation of normal tissue.
Genetic screening of the newborn is carried out to
detect inborn errors of metabolism by examination of
maternal blood, cord blood, blood & urine of
newborn.

13. Prenatal
diagnosis

14.  Prenatal diagnosis forms an integral step in genetic
counselling.
 Prenatal diagnosis can be done in:
1. It is essential for genetic disorder in which
treatment is either absent or unsatisfactory.
2. Where there can be accurate prenatal diagnosis.
3. Abnormality detected by ultrasonography.
4. Stillborn infant or recurrent miscarriages.

15.  Prenatal dignosis is must in
1. Maternal age more than 35 yrs.
2. One of the parent is balanced translocation carrier.
3. Family history of genetic disorder
4. History of exposure to teratogens
5. Parent already has a child with neural tube defect.

16. Prenatal Diagnostic Procedures
 Includes both screening and diagnostic test.
 Common procedures:
 Alpha-fetoprotein test
 Triple marker screening blood test
 Ultrasound
 Amniocentesis
 Chorionic villus sampling
 Cordocentesis
 Ivf diagnosis

17. Alpha-fetoprotein (AFP) Test
 Procedure
 Used mainly as a screening test
 Performed at 15-20 weeks
 Blood test measures the amount of AFP
 High levels reflect neural-tube defects
 Low levels reflect chromosonal abnomalities
 Advantages and Risks
 Minimal invasiveness
 High false positives

18. Triple Marker Screening
 Procedure
 Conducted at 15-16 weeks
 Blood test (triple marker)
 Human chorionic gonadotropin (hcG)
 Conjugated estriol (uE3)
 Alpha-fetoprotein (AFP)
 Used for detecting
 Chromosomal abnomalities (Downs, Edwards)
 Neural tube defects
 Advantages and Risks
 Minimal invasiveness
 Only 40%-60% accuracy rate

19. Ultrasound
 Sonogram
 Transmitter on abdomen
 High frequency sound waves echo off the fetus
 Computer enhanced picture
 Used to detect
 Head size
 Length of gestation
 Placement and structure of placenta
 Multiple pregnancies
 Anatomical abnormalities

20. Ultrasound
 Advantages
 No pain / no injection
 Minimal time (30 mins)
 No confirmed adverse biological effects on patients or
operators (Rosen & Hoskins, 2000)

21. Amniocentesis
 Procedure
 Employed only when mother is at high risk
 Done between 14 - 16 weeks.
 Needle inserted through abdominal wall
 Ultrasound is used to guide needle placement
 10 – 20 cc of fluid from amniotic sac removed
 Fetal cells tested to determine abnormalities
 Used to detect
 Chromosomal abnormalities (Down Syndrome, Edwards
Syndrome)
 Neural tube defects (Spina Bifida)

23.  Advantages and Risks
 99% accuracy of abnormality detection
 Needle may damage fetus
 Procedure linked to miscarriages in 1 in 200 pregnancies

24. Chorionic Villus Sampling (CVS)
 Procedure
 Employed only when mother is at highest risk
 Administered between 10-12 weeks
 Needle inserted through abdominal or cervix
 Ultrasound is used to guide needle placement
 Sample of the villi of the chorion collected from
placenta and tested
 Advantages and Risks
 Can detect abnormalities earlier than amniocentesis
 Carries a greater risk than amniocentesis (1 in 100
has problems, 3 in 200 linked to miscarriage)

25.  A plastic catheter is inserted through the cervix, guided
by ultrasound
Method 1: Chorionic Villus Sampling

26.  A biopsy needle is inserted through the abdominal wall
and guided by ultrasound

27. PCR

28. FISH

30. Definition
“methods used to achieve pregnancy by artificial
or partially artificial means.”
 Infertility
 Genetic reasons
 Communicable diseases, e.g. AIDS.
 Sperm donor etc…

31. In vitro fertilization
 technique of letting fertilization of the male and
female gametes (sperm and egg) occur outside the
female body.
 Embryo transfer

32. Expansions of IVF
 Transvaginal ovum retrieval (OCR) is the process
whereby a small needle is inserted through the back of
the vagina and guided via ultrasound into the ovarian
follicles to collect the fluid that contains the eggs.
 Assisted zona hatching (AZH) is performed shortly
before the embryo is transferred to the uterus.

34. Intracytoplasmic sperm injection (ICSI)

35.  zygote intrafallopian transfer (ZIFT), egg cells are
removed from the woman's ovaries and fertilized in
the laboratory; the resulting zygote is then placed into
the fallopian tube.
 gamete intrafallopian transfer (GIFT) a mixture of
sperm and eggs is placed directly into a woman's
fallopian tubes using laparoscopy following a
transvaginal ovum retrieval.

36.  Artificial insemination (AI) is when sperm is placed
into a female's uterus (intrauterine) or cervix
(intracervical) using artificial means rather than by
natural copulation.
 Surrogacy, where a woman agrees to become pregnant
and deliver a child for a contracted party. It may be her
own genetic child, or a child conceived through in vitro
fertilization or embryo transfer using another woman's
ova.

37.  surgical sperm retrieval (SSR) the reproductive
urologist obtains sperm from the vas
deferens, epididymis or directly from the testis in a
short outpatient procedure.

38.  cryopreservation, eggs, sperm and reproductive tissue
can be preserved for later IVF.

39. Adoption of a child