[Prenatal diagnosis of two fetuses with 17q12 microdeletion syndrome]

To explore the genetic etiology of two fetuses with 17q12 microdeletion syndrome.

Chromosomal karyotype analysis, whole exome sequencing (WES) and chromosomal microarray analysis (CMA) were carried out for the fetuses. Relevant literature was searched in databases such as CNKI, Wanfang and PubMed to summarize the prenatal ultrasound finding, pregnancy outcome and clinical phenotype of the syndrome.

Both fetuses were found have renal parenchymal echo enhancement, accompanied by presence of renal cysts or hydramnios. Both were found to have a normal chromosomal karyotype, but had a 17q12 microdeletion by WES and CMA analysis. A total of 433 cases of 17q12 microdeletion syndromes have been reported in the literature, with renal cysts and diabetes as the most common phenotypes. Among 240 fetuses diagnosed with this syndrome, 72.9% showed unilateral or bilateral renal parenchymal echo enhancement, and 23.3% showed unilateral or bilateral renal cysts. Among these, 68 had reported the pregnancy outcome, for which 70.5% of pregnant women had opted termination of the pregnancy.

WES and CMA can effectively detect 17q12 microdeletion. The clinical manifestations of this syndrome mainly include enhanced renal parenchymal echo, renal cyst, kidney disease and early-onset diabetes. Upon prenatal consultation, the prognosis of the fetus should be fully informed, and advice should be provided in combination with the preference of the couple, pregnancy history, family condition and other aspects.