中国无精症、严重寡精症患者的染色体异常和Y染色体微缺失

染色体异常和Y染色体微缺失被认为是两个白种人群中常见的生精障碍相关遗传因素。为了解中国无精症、严重寡精症患者中的染色体异常和Y染色体微缺失，运用染色体G显带技术，在358个原发无精症（256人）和严重寡精症（102人）不育患者中进行染色体核型分析；同时运用多重PCR技术，在核型正常的患者和100个正常生育男性中，对Y染色体AZF区微缺失进行筛查。在358个患者中，39人（10．9％）发现有染色体异常，Klinefelter（47，XYY）最为常见。无精症患者性染色体异常频率明显高于严重寡精症患者（12．1％VS1％）。在319个核型正常的患者中，46（14．4％）发现有AZF区微缺失，无精症和寡精症患者中Y染色体微缺失频率分别为15％和13．1％，AZFc区的微缺失最为常见，AZFa区的微缺失只见于无精症患者，正常生育男性中未发现AZF区的微缺失。结果显示，在中国无精症、严重寡精症患者中，大约25％的患者有染色体异常或Y染色体AZF区微缺失，提示这两种遗传异常是中国人群生精障碍的重要相关遗传病因，有必要在男性不育的诊断以及利用细胞浆内精子注射技术进行辅助生育时，对患者的这些遗传异常进行筛查。

Chromosomal Abnormality and Y Chromosome Microdeletion in Chinese Patients with Azoospermia or Severe Oligozoospermia

Chromosomal abnormality and Y chromosome microdeletion are regarded as two frequent genetic causes associated with spermatogenic failure in Caucasian population. To investigate the distribution of the two genetic defects in Chinese patients with azoospermia or severe oligozoospermia, karyotype analysis by G-banding was carried out in 358 idiopathic infertile men, including256 patients with azoospermia and 102 patients with severe oligozoospermia, and screening of AZF region microdeletion of Y chromosome by multiplex PCR was performed in those patients without detectable chromosomal abnormality and 100 fertile controls. Of 358 patients, 39(10.9%) were found to have chromosomal abnormalities in which Klinefelter's syndrome (47, XXY) was the most common chromosomal aberration. The incidence of sex chromosomal abnormality in patients with azoospermia was significantly higher than that in patients with severe oligozoospermia (12.1% vs 1%). Among the rest of the 319 patients with normal karyotype, 46 (14.4%) were found to have microdeletions in AZF region. The prevalence rates of AZF microdeletion was 15% and13.1% in patients with azoospermia and severe oligozoospermia respectively. The microdeletion in AZFc was the most frequent deletion and all the microdeletions in AZFa were found in azoospermic patients. No microdeletion in AZF region was detected in fertile controls. In conclusion, chromosomal abnormality and AZF region microdeletion of Y chromosome might account for about25% of Chinese infertile patients with azoospermia or severe oligozoospermia, suggesting the two abnormalities are important genetic etiology of spermatogenic failure in Chinese population and it is essential to screen them during diagnosis of male infertility before in vitro assisted fertilization by introcytoplasmic sperm injection.