Study of genetic diversity of KIR and TLR in the Rabhas, an endogamous primitive tribe of India.

The Rabha tribe is a little known small endogamous population belonging to Indo-mongoloid group of north-eastern India. We have analyzed 16 KIR and 5 TLR gene polymorphisms in the Rabha population of northern West Bengal, India for the first time. The observed frequencies of the KIR genes (except framework and pseudogene loci) ranged between 0.26 (KIR2DS3) and 0.96 (KIR2DL1). Comparisons based on KIR polymorphism have revealed that although the Rabhas are of Indian origin the presence of mongoloid component in their gene pool cannot be denied. The frequencies of the 5 TLR genes ranged between 0.90 (TLR4) and 0.46 (TLR5). TLR variations found in the Rabhas may play a synergistic role in fighting against the bacterial invasions. Our results may contribute to the understanding of (1) genetic background and extent of genetic admixture in the Rabhas, (2) population migration events and (3) KIR-disease-TLR interactions.