Hereditary anaemias and iron deficiency in a tribal population (the Baiga) of central India

Abstract: We have studied the prevalence and molecular nature of hereditary anaemias (abnormal haemoglobins, β‐thalassaemia, α‐thalassaemia, and Glucose 6 phosphate dehydrogenase (G6PD) deficiency) in a primitive central Indian tribe, the Baiga. 43% of the population appear to be iron‐deficient. Hereditary anaemia gene frequencies are, sickle cell 0.0824, G6PD deficiency (in males) 0.0457, β‐thalassaemia 0.0057, and deletional α‐plus thalassaemia 0.65. Both – α^3.7 and –α^4.2 deletions were observed and non‐deletional α‐thalassaemia was suspected. The overall gene frequency of Xmn I + polymorphism (C→T – 158 cap site; upstream of G gamma region) is 0.35. This polymorphism is preferentially linked to β^S genes. It appears that sickle cell disease covers a wide range of severity in the Baiga tribe based on higher mortality in the offspring of AS × AS parents (2.5/couple) compared to AA × AS (0.75/couple) and AA × AA (0.76/couple) parents. This is compatible with the high frequency of genetic modifying factors, i.e., the Xmn I polymorphism and α‐thalassaemia. The results also indicate that “normal” red cell values must be defined for each population where thalassaemias, G6PD deficiency and iron deficiency are common.