Center for Reproductive Medicine and Center for Prenatal Diagnosis, The First Hospital of Jilin University, Changchun, Jilin, China.
Braz J Med Biol Res. 2020 Feb 14;53(3):e8980. doi: 10.1590/1414-431X20198980. eCollection 2020.
The mosaic 45,X/46,XY karyotype is a common sex chromosomal abnormality in infertile men. Males with this mosaic karyotype can benefit from assisted reproductive therapies, but the transmitted abnormalities contain 45,X aneuploidy as well as Y chromosome microdeletions. The aim of this study was to investigate the clinical and genetic characteristics of infertile men diagnosed with 45,X/46,XY mosaicism in China. Of the 734 infertile men found to carry chromosomal abnormalities, 14 patients were carriers of 45,X/46,XY mosaicism or its variants, giving a prevalence of 0.27% (14/5269) and accounting for 1.91% (14/734) of patients with a chromosomal abnormality. There were ten cases (71.43%, 10/14) of 45,X mosaicism exhibiting AZF microdeletions. Case 1 and Case 4 had AZFc deletions, and the other eight cases had AZFb+c deletions. A high frequency of Y chromosome microdeletions were detected in male patients with 45,X/46,XY mosaicism. Preimplantation genetic diagnosis should be offered to men having intracytoplasmic sperm injection for hypospermatogenesis caused by 45,X/46,XY mosaicism, to avoid the risk of transfering AZF microdeletions in addition to X monosomy in male offspring.
45,X/46,XY 嵌合体核型是男性不育症中常见的性染色体异常。携带这种嵌合体核型的男性可以受益于辅助生殖治疗，但传递的异常既包含 45,X 非整倍体，也包含 Y 染色体微缺失。本研究旨在调查在中国诊断为 45,X/46,XY 嵌合体的不育男性的临床和遗传特征。在发现携带染色体异常的 734 名不育男性中，有 14 名患者携带 45,X/46,XY 嵌合体或其变体，患病率为 0.27%（14/5269），占染色体异常患者的 1.91%（14/734）。有 10 例（71.43%，10/14）为 45,X 嵌合体，表现为 AZF 微缺失。病例 1 和病例 4 存在 AZFc 缺失，而其他 8 例存在 AZFb+c 缺失。在 45,X/46,XY 嵌合体男性患者中检测到 Y 染色体微缺失的频率较高。对于由于 45,X/46,XY 嵌合体导致的少精子症而进行胞浆内精子注射的男性，应提供植入前遗传学诊断，以避免除 X 单体之外，还将 AZF 微缺失传递给男性后代的风险。
