RET and PHOX2B Genetic Polymorphisms and Hirschsprung's Disease Susceptibility: A Meta-Analysis

Background
Many publications have evaluated the correlation between RET, PHOX2B polymorphisms and Hirschsprung's disease with conflicting results. We performed this meta-analysis to clarify the association of RET, PHOX2B polymorphisms with HSCR.
Methods
We searched Pubmed, Elsevier Science Direct, China National Knowledge Infrastructure database, Chinese Biomedical database, Google scholar. The combined odds ratio (OR) with 95% CI was calculated to estimate the strength of the association. Heterogeneity and publication bias were also assessed.
Results
In total, 16 studies concerning RET and 4 studies concerning PHOX2B were included in the meta-analysis. The effects of five polymorphisms of RET (rs1800858, rs1800860, rs1800861, rs10900297, rs2435357) and one polymorphism (rs28647582) of PHOX2B were evaluated. We found a significant correlation between RET polymorphisms and HSCR. For rs1800858, the overall ORs (95% CI) of the A versus G, AA versus GG, AA/AG versus GG and AA versus GG/AG were 3.81 (2.28–6.35); 8.36 (3.45–20.25); 3.59 (1.83–7.02); and 6.60 (3.66–11.89). For rs1800861, the comparison of subjects in the G versus T, GG versus TT, GG/TG versus TT and GG versus TT/TG were 2.85(1.81–4.47); 5.38(2.68–10.80); 3.07(2.17–4.34) and 4.14(1.84–9.30) respectively. For rs10900297, the comparison results showed statistically significant. (ORC versus A = 5.05,95%CI = 4.16–6.13; ORCC versus AA = 9.73, 95%CI = 5.94–15.94; ORCC/AC versus AA = 5.31, 95%CI = 3.27–6.82; ORCC versus AC/AA = 7.06,95%CI = 5.60–8.91.) But, for rs1800860, the GG/GA versus AA did not reach statistical association (OR = 3.77, 95% CI = 0.94–15.07) and the G versus A, GG versus AA, GG versus GA/AA were 2.23 (1.60–3.11);4.56 (1.14–18.27); 2.38 (1.66–3.43) respectively. For rs2435357, the T versus C, TT versus CC, TT/TC versus CC and TT versus CC/TC were 4.53 (3.27–6.27); 11.44 (5.67–23.10); 4.04 (2.92–5.57), and 9.01(5.25–15.46).The single polymorphism of PHOX2B gene wasn't related to the risk for HSCR.
Conclusions
This meta-analysis shows a significant association between RET polymorphisms and HSCR.