性畸形四例遗传学分析

Cytogenetic analysis of four cases of hermaphroditism

在细胞遗传学核型分析的基础上，利用Ｙ染色体性决定区基因（ｓｅｘ－ｄｅｔｅｒｍｉｎｉｎｇｒｅｇｉｏｎｏｆｔｈｅＹｃｈｒｏｍｏｓｏｍｅ，ＳＲＹ）探针，对４例性畸形病例进行了Ｓｏｕｔｈｅｒｎ杂交分析。同时运用ＳＲＹ编码区的特异性引物，对其基因组ＤＮＡ进行了聚合酶链式反应（ＰＣＲ）扩增检测。结果显示：１例４６，ＸＹ女性伴性腺发育不良症；１例４５，ＸＯ／４６，ＸＹ女性表现为Ｔｕｒｎｅｒ综合征，未检出ＳＲＹ特异性杂交带及ＰＣＲ扩增带，表明其女性表型是由于缺失ＳＲＹ基因所致；１例４６，ＸＸ男性伴睾丸发育不良症，检测出与正常男性相同的杂交带及ＰＣＲ扩增带，提示基因组内有ＳＲＹ基因，可能其父亲生殖细胞在减数分裂过程中，Ｙ染色体与Ｘ染色体或常染色体之间发生了异常交换，导致患者表现为男性；１例核型为４６，ＸＸ／４７，ＸＸＹ真两性畸形患者有ＰＣＲ扩增带，而未能检出ＳＲＹ特异性杂交带，表明其基因组中存在ＳＲＹ基因，两种核型的并存导致真两性畸形。同时，Ｓｏｕｔｈｅｒｎ杂交及ＰＣＲ扩增两种检测方法比较，ＰＣＲ扩增检测更加快速、灵敏。

On the basis of cytogenetics karyotype analysis, southern blot hybridization using sex-determiningregion of the Y chromosOme(SRY) probe and amplified cation of the genomic DNA between the SRYcode region by specific primers through polymerase chain reaction(PCR)have been performed in fourcases of hermaphroditism, The results showed that,in 1 46,XY female and 145,XO/46,XY female,the SR Y specific hybridization band and PCR amplified band could not be detected; in 1 4 6,XX male,the spec ific hybridization and PCR band showed SRY gene as in normal male; in anot her truehermaphredite, the karyotype is 46,XX/47,XXY,PCR band is detectable but not hybridization band. The mec hanism of the a bnormal sex differentiation of the cases was ana lyized and the two detectionmethods were compared.