A clear, evidence-based overview of what thalassemia is, how it is inherited, how it is treated, and why carrier screening before starting a family is the single most powerful step a community can take.
This page is for general education only. It is not a substitute for advice from a qualified medical professional. Always consult your treating physician.
Thalassemia is an inherited blood disorder in which the body produces less haemoglobin than it needs. Haemoglobin is the protein inside red blood cells that carries oxygen from the lungs to every organ in the body.
When haemoglobin production is reduced, red blood cells are smaller, paler, and destroyed much faster than the body can replace them. The result is chronic anaemia — a persistent shortage of healthy red blood cells.
In its severe form (thalassemia major), this anaemia can cause fatigue, organ damage, growth delay, and — without treatment — death in childhood. With proper care, patients live full lives.
Red Blood Cells — Normal vs Thalassemia
Normal
Full of haemoglobin
Lives ~120 days
Thalassemia
Low haemoglobin
Destroyed in ~20 days
Chronic anaemia · Organ iron overload · Fatigue · Growth delay
Thalassemia is caused by a variation in the haemoglobin gene passed down from parents. You cannot ‘catch’ thalassemia.
The HBB gene
A variation in the beta-globin gene (HBB) on chromosome 11 reduces haemoglobin production. In alpha-thalassemia, it is the HBA1/HBA2 genes on chromosome 16.
Beta-thalassemia major requires inheriting one altered gene from each parent.
Remember: These are probabilities per child — not a quota. Two carrier parents could have four unaffected children, or four affected children. The 25% risk applies to every pregnancy independently.
Doctors classify thalassemia by which haemoglobin chain is affected (alpha or beta) and by clinical severity. Beta-thalassemia is more prevalent in India.
Carrier / Trait
Clinical severity
One altered gene inherited. Carriers are usually healthy and often don't need treatment. However, they can pass the gene to their children. Screening before marriage is important.
Moderate
Clinical severity
Both genes are altered but anaemia is less severe. Some patients need occasional transfusions. Many can lead largely normal lives with regular monitoring and medicines.
Severe — Cooley's Anaemia
Clinical severity
Both parents have passed on the altered gene. Without treatment, severe anaemia develops within the first two years of life. Lifelong, regular transfusions every 2–4 weeks are needed, alongside daily medicines to manage iron overload.
Thalassemia major is a lifelong condition. Treatment is not a single procedure — it is an ongoing package of care that touches every part of a patient's life.
Safe, screened, leukocyte-filtered blood every 2–4 weeks keeps haemoglobin in a safe range. TWA pioneered the use of scalp vein sets to protect veins in long-term patients. Febrile reaction rates at our centre are kept below 1%.
Each transfusion brings iron that the body cannot excrete. Without chelation medicines (deferasirox, deferiprone), iron accumulates in the heart and liver causing fatal damage. TWA provides these medicines free under the government scheme.
Ferritin, liver function, kidney function and cardiac MRI assessments every three months. All patients receive Vitamin D supplementation. Hepatitis C screening and antiviral treatment provided where needed.
School continuity, psychosocial counselling, nutrition support through Annamayil, and art therapy sessions via Camp Rainbow. TWA has assisted 9 successful deliveries within the patient cohort.
BMT can cure thalassemia for patients with a matched donor. TWA has facilitated over 300 BMTs free of cost — including haploidentical BMT through our MoU with Apollo Hospitals, Chennai. Average age of transplant has fallen as younger patients are treated first.
All five components of care are covered free of cost for our patients under the government insurance scheme — the result of years of advocacy by TWA. See our programmes →
Thalassemia major occurs only when both parents are carriers. A simple, inexpensive blood test — HbA2 quantification with a complete blood count — tells a young adult whether they carry the gene. When two carriers know in advance, they can make informed choices and access prenatal counselling before having children.
Over the last 20 years, TWA has facilitated over 100 prenatal diagnoses through an MoU with Mediscan Systems, helping prevent affected births in families who already have one child with thalassemia major. Carrier screening drives have been conducted in colleges, workplaces, and high-prevalence districts like Sitteri in Dharmapuri.
If you are already pregnant and both partners are carriers, prenatal diagnosis through chorion villous sampling (CVS) between 10–13 weeks can determine if the foetus is affected. Contact us for a referral.
If you are a patient or a family member, our helpline is open six days a week. If you want to support our work, every contribution counts.
