Beta-thalassemia Screening

Beta thalassemia screening tests identify carriers or affected individuals by evaluating blood for abnormal hemoglobin and genetic mutations. Initial tests include complete blood count and red cell indices; low MCV and microcytosis suggest screening. Confirmatory tests are hemoglobin electrophoresis or HPLC to measure HbA2/HbF and molecular DNA testing for specific gene mutations. Screening is recommended for those with family history or before pregnancy.

Hemoglobin electrophoresis or high-performance liquid chromatography (HPLC) is the best diagnostic test for thalassemia, as it identifies abnormal hemoglobin patterns. Complete blood count with red-cell indices and peripheral smear are useful screening tests. Molecular genetic testing provides a definitive diagnosis—essential for alpha-thalassemia, prenatal testing, and precise mutation identification when electrophoresis is inconclusive.

Thalassemia screening is offered preconception or at the first antenatal (booking) visit to identify carrier couples. It’s also recommended for people with unexplained microcytic anemia, those with a family history, and newborns in high-prevalence areas. If both parents are carriers, diagnostic fetal testing (CVS or amniocentesis) may be offered.

Thalassemia can be detected prenatally through genetic tests (chorionic villus sampling or amniocentesis), at birth by newborn screening, in infancy—often by 6–12 months when severe beta‑thalassemia causes anemia—or later when milder forms or carrier status are found by routine blood or genetic testing. Carrier screening is commonly offered before or during pregnancy.

Thalassemia screening identifies carriers and affected individuals early, enabling genetic counseling and informed reproductive choices to reduce births of severe disease. Early diagnosis allows timely monitoring, vaccination, iron chelation or transfusion management, preventing complications like severe anemia, organ damage, and infections. Population screening helps public-health planning, reduces treatment burden, and improves outcomes and quality of life for patients and families.

Thalassemia screening uses haemoglobin and red‑cell indices: HbA2 2.0–3.5% is normal (HbA2 >3.5% suggests β‑thalassaemia trait); mean corpuscular volume (MCV) normal 80–100 fL (MCV <80 fL suggests microcytosis/trait). Normal haemoglobin: men ~13.5–17.5 g/dL, women ~12.0–15.5 g/dL. RBC count may be normal or raised; DNA testing may be needed for confirmation.