无精子症患者的遗传学诊断

Genetic diagnosis of azoospermia

目的 :了解精子发生障碍的遗传学原因。 方法 :对 1 0 7例无精子症患者进行染色体核型分析及Y染色体微缺失的检测。 结果 :检出染色体异常核型 1 3例 (1 2 .1 % ) ,均涉及性染色体数目、结构畸变 ,其中 1 0例为 4 7,XXY ,1例为 4 7,XXY ,t(4 ;1 2 ) ,1例为 4 6X ,del(Y) ,1例为 4 6 ,XX。 4 6X ,del(Y)和 4 6 ,XX除检出SRY外 ,未检出Y染色体上与精子发生相关的其他DNA片段。检出 8例患者有Y染色体微缺失 ,AZFb +AZFc缺失 2例 ,AZFc缺失 6例 ,共占 7.5 % (8/ 1 0 7)。 1例AZFb +AZFc缺失患者 ,睾丸活检病理显示唯支持细胞综合征 ,1例生精阻滞在初级精母细胞阶段。 6例AZFc缺失患者精液细胞学检测 ,1例见初级精母细胞 ,5例见各级生精细胞。 结论 :染色体核型分析和Y染色体微缺失的检测有助于无精子症的遗传学病因诊断。

Objective: To investigate the genetic causes of spermatogenetic failure. Methods: Both karyotypic analysis and Y chromosome microdeletion diagnosis by STS PCR were performed in 107 blood specimen from azoospermic men. Results: Out of the 107 cases of azoospermia, 13 (12.1%) patients were found with number or structure aberration of sex chromosome and 8 (8.7%) of those with Y chromosome microdeletion. Among the 13 cases, there were ten patients were 47,XXY, other three were 47,XXY,t(4;12), 46,X,del(Y) and 46,XX respectively. Both 46,XX and 46,X,del(Y) were detected with only SRY but without other DNA fragments associated with spermatogenesis on Y chromosome. Of the 8 patients, there were two cases had both AZFb and AZFc deletion and six cases had AZFc deletion. Testicular pathology exhibited sertoli cell only syndrome in one case had both AZFb and AZFc deletion and another case had the same deletion and germ cells were arrested at primary spermatocytes stage. Of the 6 cases with AZFc deletion, a variety of spermatogenic cells at different levels were observed from all of the cases except for one case that only primary spermatocytes were found in the seminal specimen. Conclusion: Karyotypic analysis and detection of Y chromosome microdeletion are very helpful methods for the genetic diagnosis of azoospermia.