Retrospective study on the distribution of hemoglobinopathies in Karnataka-A laboratory experience

The importance of screening for hemoglobinopathies is well-documented in India. However, information on the distribution of hemoglobinopathies in Karnataka is lacking. The present study focuses on determining the spectrum of hemoglobinopathies for various districts of Karnataka.

A retrospective analysis of samples registered for hemoglobinopathies for a period of 5 years (2017-2021) was carried out. A total of 17066 records registered only from the Karnataka region, were anonymized and retrieved. The data included gender, age, district, and results of the tests. The results were based on complete blood count, peripheral smear, and capillary electrophoresis (CE) pattern. The data were revalidated by pathologists, and the unambiguous data were analyzed for the study. One-fourth of the records (25%) showed abnormal hematological parameters. The number of female records (66%) was twice that of males and both genders showed higher distribution of thalassemia, followed by variants and double heterozygotes (DH). Several cases of thalassemia major were identified below the age of 17 years. The majority of thalassemia cases were β thal and 93% of them were β thal trait. Among the variants, HbS was more prevalent than HbE. Among the districts, Hassan had a 35.2% thal, Mysuru had a 7.2% variant, and Chitradurga had a 5.5% DH. Thalassemia, variants, and DH were distributed across several districts of Karnataka to various levels.

The comprehensive retrospective analysis of the spectrum of hemoglobinopathies in various districts of Karnataka serves as evidence to carry out a prospective study on population screening where the incidence of thalassemia and structural variants is high.