From Genetic Insights to Public Health Action: β-Thalassemia Carrier Screening Among Youths in Delhi NCR

Background: β-thalassemia is an autosomal recessive haemoglobinopathy caused by variants in the β-globin gene, leading to a  25% chance of inheriting the affected gene if both parents are carriers. With a nationwide prevalence of 3-4%, it causes significant health challenges. However, the deficit in public education has perpetuated unawareness of the disorder among majority of the population.

Objectives: The study aims to determine the prevalence and molecular profiling of β-thalassemia carriers among youths in Delhi-NCR and promote prevention by raising awareness of carrier screening.

Methods: Following participant-informed consent and written consent, 2 mL of peripheral blood was drawn, a Complete Blood Count was performed, and the HbA2 level for the suspected cases was then determined using Hb electrophoresis. Sequencing and variant analysis were performed in cases with elevated HbA2.

Results: A total of 3022 youths (59.30% female, 40.70% male) from 16 colleges were screened between 2023 and 2025, of which 29.60% were 18 years of age, 30.80% were aged 19 years, 22.30% were aged 20 years, and 17.30% were ≥21 years of age. Using the Mentzer Index and haematological parameters, 174 samples were evaluated for Hb electrophoresis, and a final 72 samples with elevated HbA2 levels and abnormal Hb electrophoresis parameters underwent molecular analysis. Variant analysis showed 15 variants with 31.9% IVS1-5(G>C), 19.4% Cd41/42(-TCTT), 9.7% Cd26(G>A), 6.9% Cd8/9(+G), 5.6% IVS1-1(G>T), Cd30(G>T) and 619bp deletion, 4.1% IVS1-5(G>T), 2.8% Cd15(G>A) and Cd6(A>T), 1.4% Cd121(G>C), Cd48(+ATCT), Cd17/18(-CT), and the compound heterozygous Cd10(C>A)+Cd16(G>A).

Conclusion: The study showed 2.4% prevalence of haemoglobinopathy, of which 2.1% were β-thalassemia, with IVS1-5(G>C) as the most common variant. This emphasizes the importance of early screening and awareness, while also compiling variant data to help build a targeted diagnostic panel to lower the prevalence of β-thalassemia in the population.