GENETIC SIGNIFICANCE OF INCREASED FOETAL HAEMOGLOBIN

Blood samples for studying haemoglobin variants have been collected from more than two thousand persons. In this paper the comparative data on 208 normal/control, 518 gas affected and 400 tribal persons have been presented after conducting studies on cellogel electrophoretic separations. Statistical evaluation reveals that gas exposure in Bhopal in the midnight of 2-3 Dec., 1984 has resulted in increased synthesis of HbF (foetal haemoglobin) in adult population. Family studies have shown that there are 27-63% persons among control group, 42.5% among tribal group (inbred isolates) and 8% individuals among gas exposed persons who could have possessed increased HbF due to parental genes. The record of such a low percentage among gas exposed population may be due to the fact that the persons who died immediately and also gradually must have been those who would have already had increased HbF due to their heredity and also in gas response, synthesized excess of foetal haemoglobin. This assumption is supported by the statistical analysis of the present data which indicates that in the category of 10% HbF, the differences are highly significant when compared both from control, as well as tribal group. The globin chain analysis by cellogel electrophoresis was extended on selected families and some of the bands were analysed by computerised Laser densitometer. There are strong evidences that the synthesis of γ-chains has been accelerated thereby, indicating a possibility of mutation which can be only tackled at the molecular level by recombinant DNA approach.