Genetic Disorders

Genetic disorders are conditions caused by changes in DNA. Some are passed from parents (inherited), some arise from new changes in egg, sperm, or early development. Thousands of genetic disorders exist — many very rare, some relatively common in certain Indian communities. Recognising them early matters because treatment and family planning options depend on knowing the cause.

Common or important Indian genetic conditions

• Thalassaemia — carrier rates are significant in Bengali, Gujarati, Sindhi, Punjabi and several other communities.
• Sickle cell disease — tribal belt of central and eastern India.
• G6PD deficiency — causes haemolysis with certain drugs, fava beans, infection; screened at birth in many hospitals.
• Cystic fibrosis — less common than in European populations but present.
• Duchenne muscular dystrophy — affects boys; progressive muscle weakness.
• Haemophilia — bleeding disorder in males; societies active in India.
• Down syndrome, Turner, Klinefelter — common chromosomal conditions.
• Spinal muscular atrophy, Fragile X — increasingly recognised.
• Inborn errors of metabolism — congenital hypothyroidism, PKU, galactosaemia, MSUD — screened through newborn screening at many Indian hospitals.
• Consanguineous marriages (common in some communities) raise the risk of recessive genetic conditions — worth understanding.

When to consider genetic evaluation

• A child with unexplained developmental delay, multiple birth defects, failure to thrive, unusual features.
• Multiple family members with similar condition.
• Early-onset heart disease, cancer, or other conditions that cluster in family.
• Recurrent pregnancy loss, stillbirth, infant death.
• Before marriage in at-risk communities (thalassaemia, sickle cell carrier screening).
• Couple planning pregnancy with known family history.

What genetic services can do

• Genetic counselling — sort out family tree, explain risks, guide testing.
• Carrier screening — identify healthy carriers of recessive conditions.
• Diagnostic genetic testing — confirm a suspected condition.
• Prenatal diagnosis — chorionic villus sampling (CVS), amniocentesis; NIPT blood test for some conditions.
• Preimplantation genetic testing (PGT) — IVF-based; avoid transmitting known severe disease.
• Newborn screening — picks up treatable metabolic disorders before symptoms.
• Treatment — specific medicines, dietary management, gene therapy (growing); enzyme replacement; transplantation for selected disorders.
• Family support — parent networks exist for many conditions (DMD Care, Parivar for haemophilia, thalassaemia societies, etc.).

Critical Indian legal note

Prenatal sex determination is a crime in India under the PCPNDT Act. Genetic testing is available for medical conditions, not for sex selection — any lab or clinic that offers it should be reported. Preimplantation testing in IVF is also restricted to medical indications.