Prevention of homozygous beta thalassemia by premarital screening and prenatal diagnosis in India

Abstract

Aim: To determine the feasibility and acceptability of premarital screening for beta thalassemia/related hemoglobinopathies followed by prenatal diagnosis in India. Materials and Methods: Premarital testing for thalassemia carrier state was carried out in (1) extended family members (EFM) of diagnosed cases of thalassemia/hemoglobinopathies, (2) unmarried adult cases of anemia attending the hospitals' outpatient department (OPD) and (3) adult college students (CG). Hemoglobin, red cell indices were measured by a cell counter and hemoglobin fractionation was carried out by high performance liquid chromatography (HPLC). In cases with HbA2 > 3.5%, or with variant hemoglobin, mutation screen was done by amplification refractory mutation system polymerase chain reaction (ARMS- PCR). In high-risk prospective couples, premarital genetic counseling was done and prenatal diagnosis possibilities were explained. Results: The yield of carriers from EFM, OPD and CG groups was 78.17% (308/394), 19.51% (263/1348) and 4.04% (38/939), respectively. The number of prospective high-risk couples detected were 154, 48 and 2 from EFM, OPD and CG, respectively. As much as 99% of prospective carrier couples married even after knowing their high-risk status and opted for prenatal diagnosis. The program averted the birth of 33 thalassemic children; 28 in EFM group (by screening of 394 individuals), 4 in the OPD group (by screening 1348 anemic patients), and 1 in CG group (by screening of 939 students). Conclusion: Premarital screening in extended family members, followed by prenatal diagnosis is acceptable and the most effective strategy for control of thalassemia in developing countries like India.