隐睾患儿SRD5A2基因突变的检测及其临床意义

Identification of Mutation of SRD5A2 Gene in Patients with Cryptorchidism

目的探讨SRD5A2基因与睾丸下降之间的可能关系及其临床意义。 方法隐睾患儿20例,对照组10例,取外周血标本,提取白细胞:DNA组保存,继而PCR扩增SRD5A2基因第4外显子,最后进行目的基因测序。 结果30例标本PCR产物1％琼脂糖凝胶电泳,在240bp处均出现扩增基因片段,均检测出PCR扩增的约240bp的目的基因碱基序列。实验组中,有7例发现第227位密码子点突变,Arg→Gln(CGA→CAA)。对照组中,未发现有基因碱基序列改变。在实验组及对照组中,未发现有基因多态存在。 结论SRD5A2基因突变可导致隐睾,SRD5A2基因突变检测对于临床上不可扪及的隐睾治疗上有一定的指导作用。

Objective To explore possible relationship between the mutation of SRD5A2 gene and cryptorchidism occurred.Methods 20 cryptorchidy children and 10 cases of normal boys were collected as experimental group and control group respectively.The peripheral blood samples were drew by veins.DNA was extracted from leukocytes, then exon 4 of SRD5A2 gene was amplified by PCR,final the mutation detection was performed using direct DNA sequencing.Results PCR products of 30 samples were electrophoresed with 0.1% agarose,amplified gene fragment occurred at 240 bp. Aim gene 240 bp sequence amplified by PCR were all detected.DNA sequencing revealed that a point mutation transition from A to G at codon 227 in 7 cases in experimental group, leading to a substitution of Gln for Arg. Conclusion SRD5A2 gene might play a key role in the descent of testis.Therefore,we believe that the mutation of SRD5A2 gene could cause crypterchidism.The determination of the SRD5A2 gene mutation has guide significance in clinical treatment of cryptorchidism which can not palpation.