性发育异常患者的细胞分子遗传学分析

目的: 探讨性发育异常患者的细胞分子遗传学特征。方法: 应用多重连接依赖的探针扩增(MLPA)技术对3例染色体核型为46,XX的男性性反转综合征患者及1例女性假两性畸形患者父母进行SRY、CYP21A2、DSS、DAX1、WNT4、SOX9、NR5A1等性别相关基因的拷贝数筛查,并采用细菌人工染色体(BAC)克隆制备探针,以荧光原位杂交技术(FISH)进行基因定位。结果: 3例男性性反转综合征患者经MLPA基因筛查均发现存在单拷贝SRY基因,FISH技术鉴定存在2条X染色体,SRY基因易位于其中1条X染色体的短臂上;女性假两性畸形患者的母亲染色体核型为46,XX,MLPA基因筛查发现其CYP21A2-ex03杂合性缺失,CYP21A1P-ex02杂合性重复;父亲染色体核型为46,XY,MLPA基因筛查发现CYP21A2-ex01和CYP21A2-ex03杂合性缺失,CYP21A1P-ex02和CYP21A1-ex10杂合性重复。结论: 性别决定是以SRY基因为主导、其它多个基因参与的过程,对性发育异常患者进行MLPA基因筛查有利于明确病因。

Cytogenetics and molecular genetics of patients with disorder of sex deve-lopment

AIM: To explore the cytogenetics and molecular genetics of the patients with disorder of sex deve-lopment. METHODS: Three patients of 46, XX male sex-reversal syndrome and 1 patient of female pseudoherma-phroditism received gene copy number detection of sex-determining region Y gene (SRY), CYP21A2, DSS, DAX1, WNT4, SOX9, NR5A1 by multiplex ligation-dependent probe amplification (MLPA). Fluorescence in situ hybridization (FISH) analysis was also performed to map the genes using the probes from the bacterial artificial chromosome (BAC) clone. RESULTS: The single-copied SRY gene was detected by MLPA among the 3 patients of 46, XX male sex-reversal syndrome. FISH analysis revealed that there were double X chromosomes, and SRY gene was translocated to the short arm of one of the X chromosomes. Chromosome analysis of the mother of the female pseudoherma-phroditism patient was 46, XX, whose MLPA analysis showed loss of heterozygosity at CYP21A2-ex03 and amplification at CYP21A1P-ex02. Chromosome analysis of her father was 46, XY, whose MLPA analysis revealed loss of heterozygosity at CYP21A2-ex01 and CYP21A2-ex03,and amplification at CYP21A1P-ex02 and CYP21A1-ex10. CONCLUSION: Sex determination is a process controlled by SRY gene and other genes also participate in. The copy number detection of SRY gene and other genes by MLPA contributes to determine the etiology of the patients with disorder of sex development.