Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, USA.
J Urol. 2010 Apr;183(4):1636-42. doi: 10.1016/j.juro.2009.12.004. Epub 2010 Feb 20.
The causes of male infertility are heterogeneous but more than 50% of cases have a genetic basis. Specific genetic defects have been identified in less than 20% of infertile males and, thus, most causes remain to be elucidated. The most common cytogenetic defects associated with nonobstructive azoospermia are numerical and structural chromosome abnormalities, including Klinefelter syndrome (47,XXY) and Y chromosome microdeletions. To refine the incidence and nature of chromosomal aberrations in males with infertility we reviewed cytogenetic results in 668 infertile men with oligozoospermia and azoospermia.
High resolution Giemsa banding chromosome analysis and/or fluorescence in situ hybridization were done in 668 infertile males referred for routine cytogenetic analysis between January 2004 and March 2009.
The overall incidence of chromosomal abnormalities was about 8.2%. Of the 55 patients with abnormal cytogenetic findings sex chromosome aneuploidies were observed in 29 (53%), including Klinefelter syndrome in 27 (49%). Structural chromosome abnormalities involving autosomes (29%) and sex chromosomes (18%) were detected in 26 infertile men. Abnormal cytogenetic findings were observed in 35 of 264 patients (13.3%) with azoospermia and 19 of 365 (5.2%) with oligozoospermia.
Structural chromosomal defects and low level sex chromosome mosaicism are common in oligozoospermia cases. Extensive cytogenetic assessment and fluorescence in situ hybridization may improve the detection rate in males with oligozoospermia. These findings highlight the need for efficient genetic testing in infertile men so that couples may make informed decisions on assisted reproductive technologies to achieve parenthood.
男性不育的原因具有异质性,但超过 50%的病例有遗传基础。在不育男性中,已经确定了不到 20%的特定遗传缺陷,因此,大多数原因仍有待阐明。与非阻塞性无精子症相关的最常见细胞遗传学缺陷是数目和结构染色体异常,包括克氏综合征(47,XXY)和 Y 染色体微缺失。为了阐明不育男性中染色体畸变的发生率和性质,我们回顾了 668 例少精子症和无精子症不育男性的细胞遗传学结果。
2004 年 1 月至 2009 年 3 月,对 668 例因常规细胞遗传学分析而就诊的不育男性进行了高分辨率吉姆萨带染色体分析和/或荧光原位杂交。
染色体异常的总发生率约为 8.2%。在 55 例具有异常细胞遗传学发现的患者中,性染色体非整倍体占 29 例(53%),包括 27 例克氏综合征(49%)。涉及常染色体(29%)和性染色体(18%)的结构染色体异常在 26 例不育男性中被检测到。在 264 例无精子症患者中观察到 35 例(13.3%)和 365 例少精子症患者中 19 例(5.2%)存在异常细胞遗传学发现。
结构染色体缺陷和低水平性染色体嵌合体在少精子症病例中很常见。广泛的细胞遗传学评估和荧光原位杂交可能会提高少精子症男性的检测率。这些发现强调了对不育男性进行有效遗传检测的必要性,以便夫妇能够就辅助生殖技术做出明智的决定,实现生育。