Blood Groups and Haemoglobin Variants in Some Upper Castes of Bengal

Abstract

STUDENTS OF INDIAN POPULATION GENETICS are faced with a particularly complex situation, for not only are there marked regional distinctions of language and culture, but in any given area the population may be stratified into numerous endogamous castes of Hindu society and may also include Moslem and other non-Hindu religious communities as well as a diversity of tribal peoples. Even within a single major caste group, as Sangvhi & Khanolkar (I950) have shown for Brahmins of Bombay, endogamous communities may show divergent frequencies of some genes. It is therefore clear that in surveys of physical characteristics meticulous attention must be given to recording the social status and places of origin of the subjects; there are many reports, the value of which is greatly diminished by uncertainty as to the precise nature of the sample. Both anthropometric and blood grouping studies have been made in Bengal with the aim of elucidating the origin and relationships of its peoples. Majumdar & Rao (1958) following the early work of Risley (I89I) have published a detailed statistical analysis of an anthropometric survey. Comparing the metrical results for Bengal with those for Uttar Pradesh, Bihar, and Gujrat they found that Bengalis as a whole had higher cephalic indices than the peoples of Uttar Pradesh, standing between them and the brachycephalic peoples of Gujrat; they also noted that the Bengalis were distinguished from these populations by their small face size and somewhat narrow nose. The higher castes of Bengal were differentiated from the tribes and other peoples of low status by their larger head size and narrower noses. These authors also summarized the available data for ABO blood groups in Bengal and found some evidence that the tribal peoples differed from the upper castes in having rather higher B and lower 0 frequencies, while among the former the Vaidya (Baidya) caste seemed to be somewhat divergent. The distributions of the MN groups (Macfarlane I940), the Rh groups (Greval & Chowdhury I946; Venkataraman I950) and the secretor factor (Greval I 95 I; Btichi I 953) are less completely known. The present work was undertaken to provide a fuller genetical comparison of upper castes in Bengal. In addition to the ABO, MN, and Rh and secretor groups the subjects were tested for A2,P, Kell and for haemoglobin variants.