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

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.