15q11.2-q15.1微缺失产前诊断及遗传学分析

Prenatal diagnosis and genetic analysis of 15q11.2-q15.1 microdeletion

目的通过细胞遗传学及分子细胞遗传学为1例发育异常胎儿进行产前诊断,为遗传咨询提供依据。方法对胎儿及其父母进行高分辨G显带染色体分析和染色体微阵列分析(chromosomal microarray analysis,CMA)。结果脐血G显带核型结果46,XN,del(15)(q11.2q15.1)dn;CMA检测到15q11.2q15.1存约6.0Mb缺失,缺失区域涉及Angelman综合征(Angelman syndrome,AS)、Prader-Willi综合征(Prader-Willi syndrome,PWS)区域和15q13.3缺失综合征区域。胎儿父母检测结果均未见异常。结论明确胎儿15q11.2-q15.1区域发生缺失为新发异常。15q11.2-q15.1缺失综合征存在不完全外显及表现度差异,如果超声筛查提示胎儿发育异常,建议进一步产前诊断进行胎儿染色体核型及CMA检测。

Objective Through cytogenetics and molecular cytogenetics,prenatal diagnosis was made for one case of fetal dysplasia,which provided the basis for genetic counseling.Methods High resolution G-banding technology and chromosome microarray analysis(CMA)were performed on the fetus and its parents.Results The karyotype of the fetal cord blood was 46,XN,del(15)(q11.2q15.1)dn.The results of CMA showed 6.0 Mb deletions in 15q11.2q15.1,which involved Angelman syndrome(AS),Prader-Willi syndrome(PWS)and 15q13.3 deletion syndrome.The parents of the fetus showed no abnormal results in karyotype and CMA detection.Conclusions The deletions in 15q11.2-q15.1 was identified as a novel abnormality.15q11.2-q15.1 deletion syndrome has incomplete penetrance and expression difference.If ultrasound screening indicates fetal dysplasia,further prenatal diagnosis of karyotype and CMA detection are recommended.