Haemoglobinopathies in eastern Indian states: a demographic evaluation

Area of Science:

• Genetics
• Hematology
• Public Health

Background:

• Haemoglobinopathies are a major global child mortality cause with varied incidence.
• Accurate prevalence data is crucial for burden reduction, yet eastern India remains understudied.
• Existing Indian studies are often hospital-based or regionally limited, potentially misrepresenting disease burden.

Purpose of the Study:

• To estimate the prevalence of haemoglobinopathies in eastern India, a poorly studied region.
• To characterize the distribution and spectrum of beta-thalassaemia trait (BTT), sickle cell haemoglobin trait (HbS)/haemoglobin E trait (HbE), and alpha-globin defects.
• To investigate the association between low HbA2 levels and nutritional deficiencies.

Main Methods:

• Conducted a study on 1,642 individuals from Bihar, Chhattisgarh, Jharkhand, and eastern Uttar Pradesh.
• Assessed carrier frequencies for BTT, HbS/HbE, and alpha-globin defects.
• Analyzed mutation spectrum of BTT and investigated HbA2 levels in relation to vitamin B12 and folate status.

Main Results:

• Identified carrier frequencies of 3.4% for BTT, 3.4% for HbS/HbE, and 18% for alpha-globin defects.
• Observed uniform BTT mutation distribution, while HbS was concentrated in tribal-rich Chhattisgarh and Jharkhand.
• Found a high frequency of alpha-globin mutations, even in individuals with normal blood counts, and a distinct BTT mutation spectrum.

Conclusions:

• The study provides crucial carrier frequency estimates for beta-thalassaemia traits in eastern India.
• Confirms a high prevalence of alpha-globin defects and highlights regional heterogeneity in HbS distribution.
• Demonstrates an association between low HbA2 levels and vitamin B12/folate deficiency in this cohort.