LRP5／6基因多态性与先天性巨结肠症的相关性研究

Association of LRPS/6 gene polymorphism and Hirschsprung＇s disease

目的通过对低密度脂蛋白受体相关蛋白5／6（low dens.ity lipoprotein receptor-related protein 5/6, LRP5/6）基因单核苷酸多态性（single nucleotide polymorphisms，SNPs）基因型与先天性巨结肠症（Hirschsprungdisease’s，HD）的相关性研究，探索可能潜在的致病基因。方法采集200例临床确诊的HD患儿（病例组），200名健康儿童（对照组）的外周静脉血，提取白细胞基因组DNA，PCR扩增LRP5／6基因4个位点（rs121908674，rs121908671／rsl21918313，rs117554756），将PCR产物测序进行突变筛选，明确突变位点和类型，并进一步结合病例-对照和生物信息学分析探讨基因变异的意义。结果病例组与对照组LRP5rs121908671、LRP6 rs117554756AA和AG、AA和AC基因型频率无显著性差异（P〉0．05）；而病例组与对照组LRP5rs121908674CC、CG和GG基因型频率及C和G等位基因频率差异显著（P〈0．05），CC和CG基因型及G等位基因的患病风险分别为0．005、0．195和0．001；LRP6rs121918313CC、CT和1vr基因型频率及C和T等位基因频率差异显著（P〈0．05），CC和CT基因型及T等位基因的患病风险分别为0．012、0．504和0．003。LRP6基因rs121918313测序检出有杂合性缺失和单碱基的替换，第131位密码子核苷酸AAA→CAA。结论LRP5／6基因多态性位点可能对HD有影响，并且可能有一定的遗传性。

Objective To explore the relationship between low density lipoprotein receptor-related protein 5/6 （LRP5/6） genes and the genotypes of single nucleotide polymorphisms （SNPs） of Hirschsprung＇s disease （HE））. Methods A total of 200 children of HD （case group） and 200 healthy children （control group） were recruited to obtain genomic DNA from peripheral blood leukocytes. Polymerase chain reaction （PCR） amplification was performed for LRP5/6 genes （rs121908674, rs121908671/rs121918313, rs117554756） and PCR products were sequenced for mutation screening. Case-control study and bioinformatie analyses were utilized to explore the potential roles of variations. Results No significant inter-group differences existed in allelic and genotypic frequencies of AA and AG for rs121908671 （P〉0. 05）. LRP6 gene rs117554756 allelic and genotypic frequencies of AA and AC existed between patients with HD and the control group （P〉0. 05）. The allelic and genotypic frequencies in LRP5 gene rs121908674 as well as the genotypes of CC, CG and GG were related in two groups （P〈0.05）. C and G polymorphisms were present in HD. The disease risks of genotype of CC and GG and allelic gene of G were 0. 005,0. 195 and 0. 001 respectively. The allelic and genotypic frequencies in LRP6 gene rs121918313 and the genotypes of CC, CT and TT were related in two groups （P〈0. 05）. C and T polymorphisms were present in HD. The disease risks of genotype of CC and CT and allelic gene of T were 0. 012, 0. 504 and 0. 003 respectively. And rs121918313 sequencing demonstrated a loss of heterozygosity and single nucleotide substitution. The single nucleotide substitution for rs121918313 was confirmed in HD： AAA→CAA at position 131. Conclusions The polymorphisms may affect HD in LRP5/6 genes so as to carry a hereditary tendency.