摘要：
Objective To analyze the deletion region for two fetal cases with large Yq deletions in order to provide genetic counseling and prenatal diagnosis.Methods For both cases,amniotic fluid samples were cultured and analyzed with G banding and fluorescence in situ hybridization (FISH).Multiplex polymerase chain reaction was also carried out to amplify 15 sequence tagged sites (STS) of azoospermia factor (AZF) on the Y chromosome.Results For both samples,the karyotypes were determined as 46,X,del(Y) (pter→q11:).No heterochromatin was found in C band.The karyotypes of their fathers were 46,XY,and heterochromatin was found in C band.STS analyses suggested that only sY82,sY84 and sY86 in AZFa were amplifiable while the other 12 STS were negative in amniotic fluid for the first case,which indicated deletions of AZFb,AZFd and AZFc.No AZF deletion was found in its father.For the second case,all 15 STS were amplifiable in the amniotic fluid,suggesting no AZF deletion.No AZF deletion was found in its father too.Conclusion Conventional karyotyping combined with FISH and molecular genetics techniques can enable characterization of AZF microdeletions and facilitate genetic counseling and prenatal diagnosis.%目的 对两例羊水细胞Y染色体长臂大片段缺失病例进行分析,为产前诊断提供遗传咨询.方法 对两例羊水细胞进行培养,采用显带技术、荧光原位杂交(fluorescence in situ hybridization,FISH)技术及多重PCR技术扩增Y染色体长臂无精子因子(azoospermia factor,AZF)区15个序列标签位点(sequence tagged site,STS).结果 两例羊水FISH检测提示为46,XY,染色体核型核型为46,X,del (Y)(pter→q11∶),C显带证实无异染色质,Yq末端缺失,孕妇丈夫外周血细胞染色体46,XY,C显带有异染色质.例1孕妇羊水所扩增的STS只有AZFa区sY82、sY84、sY86有特异扩增条带,其余12个STS均未见特异扩增条带,提示AZFb、AZFd、AZFc区缺失,其丈夫未见AZF区缺失.例2孕妇羊水15个STS均见特异扩增条带,未见AZF区缺失,其丈夫未见AZF区缺失.结论 常规染色体检查与FISH技术及分子遗传学技术的联合应用,对孕妇羊水Y染色体AZF微缺失进行检测,可为产前诊断提供遗传咨询帮助.
