摘要目的 检测MSX-1基因单核苷酸多态性(single nucleotide polymorphism,SNP)位点在单纯性散在性先天性缺失牙患者和健康人群中的分布情况,为寻找单纯性散在性先天性缺失牙的易感因素奠定基础.方法 应用聚合酶链反应-限制性片段长度多态性检测198例先天性缺失牙患者(病例组:包括非下颌前牙缺失组95例和下颌前牙缺失组103例)和207名健康人(对照组)2个SNP位点(rs3821949和rs12532)的基因型;卡方检验分析两组SNP位点等位基因频率和基因型频率;用Phase软件构建单倍型,并分析病例组与对照组单倍型频率的差异.结果 病例组rs3821949位点A等位基因频率(43.2%)显著高于对照组(31.4%),病例组rs3821949位点AA基因型频率(14.7%)显著高于对照组(12.6%),差异均有统计学意义(P值分别为0.008和0.030).SNP位点rs12532与单纯性散在性先天性缺失牙无相关性.单倍型分析可见4种单倍型,其中非下颌前牙缺失组的GA单倍型分布频率(27.9%)比对照组低(37.0%,P=0.03,OR:0.51).结论 MSX-1基因编码区SNP位点rs3821949与单纯性散在性先天性缺失牙有明显的相关性,有A等位基因的人群发生先天性缺失牙的危险性相对高.两个SNP位点所构成的GA单倍型可能与导致非下颌前牙先天性缺失的易感基因相连锁.

abstractsObjective To study the relationships between single nuchotide polymorphisms (SNP) of gene rash homebox-1(MSX-1)(rs3821949,rs12532)and sporadic tooth agenesis by filtering the susceptibility genes in a Jiangsu province population.Methods DNA samples were extracted from 198 patients with sporadic tooth agenesis and 207 control subjects.Two MSX-1 gene polymorphisms were genotypod using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay.The association between the genetic polymorphism and risk of sporadic tooth agenesis wag estimated by χ2 and logistic regression.The Phase wag used to determine the Hardy-Weinberg equilibrium and haplotype association.Results In the population,the allele frequency and genotype rates of the SNP rs3821949 were significant different between the patients with sporadic tooth agenesis and normal controls:the A allele frequency in the patients (43.2%) was significantly higher than that in the normal controls (31.4%,P=0.008),and the AA genotype rate ofthe patients (14.7%) was significantly higher than that of the controls (12.6%,P=0.030).However,There were no significant diffeFences in the allele frequency and genotype rates of the SNP rs12532 between the patients with sporadic tooth agenesis and normal control s.Similar results were obtained between the mandibular ineisor agenesis cases and controls.The haplotype frequencies of GA(27.9%)were significantly lower in non.mandibular incisor agenesis cases group than that in the control group(37.0%,P=0.03,OR=0.51).Conclusions The results show that SNP rs3821949,which is located at 5'near region of the MSX-1 gene,is likely to have an influence on the transcriptional activity of this gene and be associated with sporadic tooth agenesis.The haplotypes constructed with these 2 SNP sites may be linked with the susceptibility gene of non-mandibular incisor agenesis.