尿道下裂与Ⅱ型3β羟类固醇脱氢酶基因突变的研究

Screening Mutations of Type II 3 Betal-hydroxysteroid Dehydrogenase Gene in Hypospadias

目的探讨尿道下裂的发生与Ⅱ型3β羟类固醇脱氢酶基因突变的关系。方法抽取47例尿道下裂患儿和32例包茎患儿静脉血,提取白细胞基因组DNA,PCR扩增Ⅱ型3β羟类固醇脱氢酶基因的第2、4外显子片段,SSCP电泳检测扩增片段。结果47例尿道下裂患儿 II型3β羟类固醇脱氢酶基因的第2外显子在270bp处均可见特异性扩增带,2例第2外显子的SSCP条带有异常泳动,第4外显子和对照组2、4外显子均未发现有异常泳动条带。结论在尿道下裂病儿中存在雄激素合成酶-Ⅱ型3β羟类固醇脱氢酶基因突变,尤其是严重的尿道下裂。雄激素合成酶的功能缺陷可能是先天性尿道下裂发生的原因之一。

Objective To explore the relationship between the etiology of hypospadias and the type II 3-betal-hydroxysteroid dehydrogenase (3-β-HSD II) gene mutation. Methods The venous blood was draw from 47 cases of hypospadias (experimental group ) and 32 cases of phimosis. DNA was extracted from leukocytes genome.The fragments of exon 2 and exon 4 of the 3-β-HSD II gene were amplified using polymerase chain reaction (PCR), and the mutations of these fragments were detected using single strand conformation polymorphism (SSCP) technique. Results A specific exspanding strap at the 270 bp of exon 2 of 3-β-HSD II gene was seen in 47 children with hypospadias,distict abnormal straps were detected by SSCP in 3-β-HSD II gene from 2 cases of severe hypospadias. Conclusions These findings suggest that mutation of 3-β-HSD II gene existed in the children with hypospadias, especially in the severe cases,the deficiency of the 3-β-HSD II ,which one of androgen synthetases, migth be one of the etiology of hypospadias,