性分化异常的遗传学诊断

Genetic Diagnosis in Abnormalities of Sexual Differentiation and Development

目的 :研究SRY基因在性分化和发育中的作用。方法 :细胞遗传学核型分析技术结合PCR技术检测外周血SRY基因。结果 :在 12例性分化异常患者中 ,有 7例核型为 4 6 ,XY ,SRY(+) ,其中 1例为睾丸女性化综合征。说明性腺病理有睾丸与外周血SRY相符。另有 5例核型为 4 6 ,XX。其中 1例外周血SRY(+) ,显示性反转综合征 ;1例为Turner嵌合型综合征 ,核型为 4 6 ,XX 4 5 ,X ,SRY(- ) ,但睾酮升高 (12 7nmoL L)。正常成年女性睾酮参考值 (0 7～ 2 8)nmoL L。 3例外周血SRY为 (- )。结论 :SRY基因检测比外周血核型更能预示睾丸组织的存在 ,性腺的病理取决于性腺部位的染色体核型和SRY基因。除SRY基因外 ,可能存在多个参与性别决定和分化的基因。

Objective:To study the role of SRY gene in abnormalities of sexual differentiation and development.Me thods: The karyotype analysis technique of the cytogenetics combined with polymerase chain reaction(PCR)was used to detect the SRY gene of peripheral blood.Results:Among the 12 cases in abnormalities of sexual differentiation and development,7 cases were the blood karyotype of 46,XY,blood SRY positive,one of 7 presented the testicular feminization syndrome.And 5 of 12 were the blood karyotype of 46,XX,one of 5 presented blood SRY positive,showing the sex reversal syndrome,and one was the blood karyotype of 46,XX/45,X,blood SRY negative,but the testosterone was up to 12 7nmoL/L[(0 7～2 8)nmoL/L in the normal female adult].Conclusion:SRY gene detection is more sensitive and specific than blood karyotype in the prediction of the presence of testicular tissue.It is not necessary that peripheral blood karyotype reflects the type of the gonads.The SRY gene is the best candiation gene of the testis determining factor.The sex differential abnomality expresses highly the genetic heterogeneity.