中文摘要：

目的：研究中国汉族人群中雄激素受体基因（AR）第一外显子上的（CAG）n多态性与男性尿道下裂发病风险的相关性。方法研究对象为342例男性尿道下裂患儿以及351例健康人。从外周血淋巴细胞中提取全基因组DNA，对AR基因上的第一外显子（CAG）n进行PCR扩增，扩增产物以Sanger测序方法对其测序，计算各样本的（CAG）n分布情况。采用卡方检验（Chi-square test）比较病例组与对照组之间的（CAG）n分布，并分析（CAG）n对男性尿道下裂发病风险的影响。结果病例组（CAG）n为15～44，平均长度23．65±3．36；对照组为19～31，平均长度23．14±1．87，两组CAG重复序列有明显统计学差异（P＝0.013）。当n≥23，24，25，26时，尿道下裂发病风险分别为1．47（CI：1．081～2．001），1．356（CI：1．004～1．830），1．484（CI：1．063～2．071），1．565（CI：1．034～2．369），各组均有明显统计学意义（P＜0.05）；而当n≤19时，尿道下裂患病风险为2．111（CI：0．935～4．767），P＝0.05。结论 AR基因第一外显子上的（CAG）n与男性尿道下裂发病有明显的相关性，CAG重复序列越长，尿道下裂的发病风险越高。

英文摘要：

Objetive To analyze the risk for hypospadias in Han Chinese modified by the CAG repeat polymorphismintheexon1ofAndrogenReceptorgene.Methods DNAwasextractedformperipheralblood samples which came from 342 cases with hypospadias and 351 healthy voluntary anonymous blood sample do-nors.The CAG repeat lengths were amplified with PCR,which were calculated the difference between the hy-pospadiasandcontrolgroupusingChi-squaretest.Results ThemeanlengthofCAGinhypospadiaswas 23.65 ±3.36 （range 1 5 -44）,and it was 23.1 4 ±1 .87 （range 1 9 -31 ）in control group.A significant in-crease of the CAG repeat length in hypospadias group was detected when compared with the controls （P=0.01 3 ）.In addition,the odds ratios between the hypospadias and controls revealed that the hypospadias cases are about 1 .5 times to have longer CAG repeats than a shorter length for each repeat length investigated. Con-clusion WehaveinvestigatedalargenumberofhypospadiascaseswithregardstotheCAGrepeatlength,and we provided evidence that a higher number of the CAG repeat sequence in the AR gene have a clear effect on the risk of hypospadias in Han Chinese.