Y长臂部分缺失伴X单体嵌合性发育异常胎儿1例的产前诊断及遗传学分析

Prenatal diagnosis and genetic analysis of a fetus with partial deletion of Yq and mosaicism of 45,X

目的对1例性发育异常(DSDs)胎儿进行产前诊断和遗传学分析。方法选取2021年9月于深圳市人民医院发现的1例DSDs胎儿为研究对象。联合应用荧光定量PCR(QF-PCR)、多重连接探针扩增(MLPA)、染色体微阵列分析(CMA)、实时荧光定量PCR(qPCR)等分子遗传学技术以及核型分析、荧光原位杂交(FISH)等细胞遗传学技术进行分析。用超声检查胎儿性发育的情况。结果分子遗传学检测提示胎儿可能存在Yq11.222qter缺失与X单体的嵌合, 结合细胞遗传检测确定其核型为mos 45, X[34]/46, X, del(Y)(q11.222)[61]/47, X, del(Y)(q11.222), del(Y)(q11.222)[5], 超声检查发现胎儿存在尿道下裂, 产前诊断胎儿为DSDs, 引产后证实。结论综合应用多种遗传学检测技术及超声检查, 完成了1例具有复杂核型的DSDs胎儿的产前诊断。

Objective To carry out prenatal diagnosis and genetic analysis for a fetus with disorders of sex development(DSDs).Methods A fetus with DSDs who was identified at the Shenzhen People's Hospital in September 2021 was selected as the study subject.Combined molecular genetic techniques including quantitative fluorescence PCR(QF-PCR),multiplex ligation-dependent probe amplification(MLPA),chromosomal microarray analysis(CMA),quantitative real-time PCR(qPCR),as well as cytogenetic techniques such as karyotyping analysis and fluorescence in situ hybridization(FISH)were applied.Ultrasonography was used to observe the phenotype of sex development.Results Molecular genetic testing suggested that the fetus had mosaicism of Yq11.222qter deletion and X monosomy.Combined with the result of cytogenetic testing,its karyotype was determined as mos 45,X[34]/46,X,del(Y)(q11.222)[61]/47,X,del(Y)(q11.222),del(Y)(q11.222)[5].Ultrasound examination suggested hypospadia,which was confirmed after elective abortion.Combined the results of genetic testing and phenotypic analysis,the fetus was ultimately diagnosed with DSDs.Conclusion This study has applied a variety of genetic techniques and ultrasonography to diagnose a fetus with DSDs with a complex karyotype.