Patterns of social and geographical distribution of transferrin subtype polymorphism in India

Transferrin subtypes have been determined by isoelectric focussing of sera from 536 individuals belonging to 9 South Indian populations: Vaidic Brahmins and Vaysya from Andhra Pradesh; Havik Brahmin, Lingayat and Jenu Kuruba from Karnataka; Namboodri Brahmin, Ezhava and Urali from Kerala; and Kallan from Tamil Nadu. C1 and C2 alleles are present in all the populations, whereas C4 is totally lacking and D1 occurs only in 3 populations. The highest frequency of C1 gene (0.814) is found in Havik Brahmins while C2 shows highest incidence among the tribe Urali. C1 occurs in slightly higher frequencies among the Hindu castes (range 0.724-0.814) than the tribal populations (range 0.698-0.703). C2 is more common in the tribes (range 0.281-0.290) compared to the castes (range 0.186-0.269). Strikingly the C3 allele is absent in all the 3 Brahmin samples but is present in 3 non-Brahmin castes and a tribal population. An examination of all the available data on Tf subtypes in India reveals no clear-cut decreasing north-south gradient in C1 gene as suggested by Walter et al. (1983). Interestingly, however, the same is observed when tribal populations are considered separately. Among the castes, in fact, the opposite trend (increasing north to south) is seen. It is suggested that the basic postulate of Walter et al. (1983) will hold good only among the tribal populations of the country. The data do not fully support the observation of Kamboh and Kirk (1983) that C3 is a specific marker of European (Caucasian) populations.