Background: Hirschsprung disease (HSCR) is a complex genetic disorder, which characterized by absence of ganglion cells along variable lengths of the intestines in neonates, with the RET was identified as a major locus involved in HSCR. In this study, we investigated the joint effects of common variants within the RET transcriptional enhancer, rs2435357 and rs2506030, for development of HSCR in Indonesia.
Methods: Sixty HSCR patients and 122 non-HSCR controls was involved in this study. Two genetic markers of the RET were examined using TaqMan assay. We analyzed the case-control association tests between two genetic markers and HSCR using the statistic. A P value <0.025 is considered significant given that two tests (markers) were performed in the analysis.
Results: There was high correlation between RET rs2435357 marker and HSCR either by case-control analysis (OR =4.46, P=2.5×10−8) or transmission disequilibrium test (TDT, P=4.2×10−6), but not RET rs2506030 (OR =1.68, P=0.042 and P=0.034, respectively). Two locus analyses of variants revealed that RET rs2435357 (TT), in combination with rs2506030 (GG), were associated with the increased disease risks of HSCR (OR =5.42, P=3.9×10−6) compared with a single variant of rs2506030.
Conclusions: Our study shows that RET rs2435357 variant is a strong genetic risk factors for development of HSCR in Indonesia. In addition, the disease effects of RET rs2506030 genotypes are crucially dependent on the effects of rs2435357 genotypes.