SNPs in 3′-UTR region of MBL2 increases susceptibility to recurrent vulvovaginal infections by altering sMBL levels

Abstract

Recurrent vulvovaginal infections (RVVI), owing to their adverse health consequences, have become a serious dilemma worldwide. Low serum levels of Mannose-Binding Lectin (sMBL), a main component of innate immunity, was found to be associated with RVVI risk, though complete genetic bases are still elusive. To reveal unrecognised regulatory variants, 3′-UTR region of MBL2 with six putative functional SNPs i.e. rs10824792, rs2120132, rs2120131, rs2165813, rs2099903 and rs2099902 was sequenced and genotyped in the present study for 109 RVVI cases and age matched healthy controls. sMBL levels were measured by enzyme-linked immunosorbent assay. The homozygous CC genotype of rs10824792 polymorphism was found to be conferring risk (OR = 2.94) of developing RVVI. Significantly high frequency of corresponding CC genotype was found in Vulvovaginal Candidiasis (VVC) and Mixed Infections (MI) relative to controls. Significantly insufficient sMBL levels were observed in RVVI and its types (Bacterial Vaginosis, VVC and MI) than controls. sMBL levels varied for rs10824792 SNP as expected from the genetic analyses. Six marker haplotype analyses have shown CTTGCT, the haplotype containing only risk allele of rs10824792, conferred risk of RVVI and its types by lowering sMBL levels. In conclusion, a 3′-UTR SNP i.e. rs10824792 was identified as novel associated genetic marker for contributing low sMBL levels and RVVI risk. Our findings contribute to the novel future research directions for the development of emerging MBL substitution as effectual therapy for RVVI.