Celebrating World Thalassemia Day
In India, approximately 12,000 babies born every year have an inherited blood disorder leading to significant health complications. Thalassemia — one of the most common inherited blood disorders — is a genetic condition in which abnormal production of haemoglobin results in varying degrees of health concerns. In India, about 1 in 25 Indians are carriers of beta-thalassemia.
Alpha Thalassemia
Abnormally formed alpha chains of haemoglobin cause alpha thalassemia. It is clinically classified into two forms:
Hydrops fetalis / Hb Bart Syndrome (Alpha Thalassemia major) — a severe form; babies may be stillborn or pass away soon after birth. Pregnant mothers may also be at risk of complications including hypertension, premature delivery, and abnormal bleeding
HbH disease — a milder form presenting in infancy or early childhood with mild to moderate anaemia, enlargement of spleen and liver, and yellowing of the eyes and skin
Beta Thalassemia
Beta thalassemia is characterised by low amounts of beta-haemoglobin chains causing hypochromic anaemia. It is classified into:
Thalassemia major (Cooley’s anaemia) — clinical symptoms appear between 6 and 24 months; requires regular blood transfusions every 2–3 weeks
Thalassemia intermedia — symptoms present in early or late childhood; moderate to severe bone deformities and liver/spleen enlargement
Genetics and Inheritance
Alpha thalassemia is caused by deletions in the HBA1 and HBA2 genes (autosomal recessive). Beta thalassemia is caused by disease-causing changes in the HBB gene (autosomal recessive). When both parents are carriers, their children have a 25% chance of having thalassemia, a 50% chance of being a carrier, and a 25% chance of being unaffected.
Carrier Screening for Thalassemia
Carrier screening is recommended for any couple with Indian ancestry planning a pregnancy, individuals with a family history of thalassemia, and individuals opting for donor sperm or egg. When both parents are carriers, their children are at risk of having complications due to thalassemia.
Resources for Families with Thalassemia
Carrier Screening and Genetic Counselling for Thalassemia
MapmyGenome offers carrier screening covering 171 genetic conditions — including alpha and beta thalassemia — with certified genetic counselling from India’s most experienced team. CAP & NABL-accredited laboratory.
