Indications for Genetic study

1. Advanced maternal age.
   
2. Couples who are known to be at high risk for producing a child with congenital disorder.
   
3. Couples with repeated fetal loss.
   
4. Dysmorphic features in child suggestive of chromosomal disorder.
   
5. Unexplained mental retardation.
   
6. Unexplained still birth.
   
7. Multiple congenital abnormalities.
   
8. Primary infertility.
   
9. Ambiguous sexual development.
   
10. Certain inherited disorder like Thalassemia, Muscular dystrophy, Cystic fibrosis etc.
    
11. Previous child with metabolic disorder.
    
12. Certain type of cancer (CML,ALL,AML,MDs).

Indications For Prenatal Genetic Diagnosis

1. Advanced maternal age pregnancy.
   
2. Triple marker screening positive during pregnancy.
   
3. Previous child with abnormality like Down syndrome, Fragile-x, Prader willi syndrome.
   
4. Structural abnormality of chromosome in either parent.
   
5. Medical disease in mother; Diabetes mellitus, Phenylketone urea.
   
6. Infection during pregnancy: Rubella, toxoplasma, cytomegalovirus.
   
7. Exposure to teratogen during early pregnancy.
   
8. Balanced translocation in either parent.
   
9. Inherited disorder like: Beta thalassemia, Duchenne Muscular Dystrophy, SMA, Hemophilia,.Gaucher disease,.MPS etc.
   
10. Certain ethnic risk factors: Tay-Sachs, Sickle cell, Hemophilia etc.

General Risk Factors

The general population risk of certain disorders is as follow where genetic study might be helpful:

Condition	Risk
Spontaneous miscarriage	1 in 6
Prenatal Death	1 in 30-100
Neonatal Death	1 in 150
COT Death	1 in 400
Major congenital malformations	1 in 33
Adult cancer	1 in 4
Serious mental or physical handicap	1 in 50

The most common general population risk is Down syndrome with the birth frequency of 1 in 600 to 100