Host genetic factors including major histocompatibility complex (MHC) polym
orphisms influence both susceptibility to leprosy per se and also to lepros
y type. Non-h IHC genes may play an important role, but such genes remain u
ndefined. The influence of two non-MHC candidate genes was assessed in a ca
se-control study of Bengali leprosy patients from Calcutta, Recent studies
have implicated variation in the vitamin D receptor (VDR) gene in susceptib
ility to several diseases, including osteoporosis and pulmonary tuberculosi
s, In this population, homozygotes for the alternate alleles of the VDR pol
ymorphism are associated, respectively, with lepromatous and tuberculoid le
prosy. The NRAMP1 (natural resistance associated macrophage protein 1) gene
may influence human mycobacterial disease susceptibility based on studies
with the murine homologue Nramp1. However, no significant association was f
ound between NRAMP1 and leprosy susceptibility, This study suggests that th
e VDR polymorphism may influence susceptibility to some diseases by affecti
ng the type and the strength of the host immune response.