Mutations and polymorphisms of Hirschsprung disease candidate genes in Thai patients

Abstract

Mutation and polymorphism data for Hirschsprung disease (HSCR) varies among ethnic groups. Single nucleotide polymorphisms (SNP) of RET proto-oncogene (RET) were recently shown to be associated with the disease, and with disease severity, in different populations. In this study, comprehensive analysis of RET, GDNF, EDNRB, ET-3, and SOX-10 genes among sporadic HSCR in Thailand was conducted by standard PCR-SSCP, RFLP, and sequencing methods. Of 41 patients, 30 cases had rectosigmoid disease (RSD) and 11 cases were assigned to the long-segment disease (LSD) group. Four missense mutations of RET, S100M, R231H, T278N, and G533S, were identified in three patients. One novel missense mutation, V111Q, was detected in EDNRB. For ET-3, two novel missense mutations, D166E and C173R, occurred concomitantly in a patient. The incidence of missense mutation was significantly higher in our female HSCR patient than in the male counterpart. Statistical analysis of the SNPs revealed a significant difference between allele distribution of RET L769L in patients in the LSD and RSD groups. The predominant genotype construct of RET A45A/L769L in our HSCR was GG/GG, which is obviously different from results from all previous studies. The GG/GG genotype construct was associated with RSD and with males. The study also detected a variant allele of RET S836S which has never been reported in Asian cohorts.