Interleukin-17F single-nucleotide polymorphism (7488T>C) and its association with susceptibility to leprosy

The objective of this study was to investigate the association, if any, between the interleukin-17F (7488T>C) (rs763780) polymorphism and susceptibility to leprosy and to elucidate the relationship between IL-17F genotypes and clinical profile of the disease. DNA was extracted from the peripheral venous blood of leprosy cases (n=140), which were classified as per WHO classification into paucibacillary (PB) (n=53) and multibacillary (MB) (n=87) categories and healthy controls (n=84) without any signs and symptoms of leprosy. The IL-17F (7488 T/C) polymorphism was genotyped using amplification refractory mutation system - polymerase chain reaction (Allele-specific amplification). In both PB and MB categories of leprosy cases, the homozygous TT genotype frequency was significantly higher than that of the healthy controls (78.70% vs. 29.76%, P<0.05). The heterozygous TC genotype was higher in the controls than in the leprosy cases (57.14% vs. 17.68%, P<0.05). TT genotype was more associated with the type 1 reactional states and tuberculoid/borderline tuberculoid groups in leprosy than the TC genotype. This study reveals that the IL-17F (7488T>C) single-nucleotide polymorphism is associated with susceptibility to leprosy and polymorphism confers decrease in risk of contracting leprosy in the north Indian cohort.