Objective:To analyze ultrasonographic manifestations and genetic etiology of nine fetuses with 7q11.23 duplication syndrome.Methods:Ultrasonographic finding, pregnancy outcome and follow-up of nine fetuses detected at the Prenatal Diagnosis Center of the Third Affiliated Hospital of Zhengzhou University from January 2017 to December 2021 were retrospectively analyzed.Results:The fetuses were found to harbor a duplication in the 7q11.23 region by chromosomal microarray analysis (CMA). Among these, five had shown ventriculomegaly, including four syndromic and one non-syndromic. For the remainders, one had ventricular septal defect and mild tricuspid regurgitation, one had echogenic intracardiac focus, whilst another two were normal. Five couples had accepted parental verification, and the results confirmed that the 7q11.23 duplication carried by their fetuses were de novo in origin. Following genetic counseling, seven couples had opted to terminate their pregnancies. Two fetuses were delivered at full term, and follow-up had found no abnormalities. Conclusion:Prenatal ultrasonographic manifestations of fetuses with 7q11.23 duplication syndrome are variable. CMA can provide assistance for their diagnosis and genetic counseling.

Objective:To explore the clinical characteristics and variant of CREBBP gene in a fetus with Rubinstein-Taybi syndrome (RSTS). Methods:A fetus with RSTS diagnosed at the Third Affiliated Hospital of Zhengzhou University in August 2022 was selected as the study subject. Clinical data, amniotic fluid sample of the fetus and peripheral blood samples of its parents were collected for whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing.Results:Foot malformation, cerebellar vermis agenesis, brain agenesis, polysyndactyly of the big toes and other phenotypes were found by prenatal ultrasound. WES revealed that the fetus has harbored a heterozygous c. 4684G>T (p.E1562*) variant in exon 28 of the CREBBP gene (NM_004380.3), which was de novo in origin. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be pathogenic (PVS1+ PS2_Moderate+ PM2_Supporting). After genetic counseling, the couple had opted to terminate the pregnancy and refused autopsy for the fetus. Conclusion:The c. 4684G>T (p.E1562*) variant of the CREBBP gene probably underlay the RSTS in this fetus. The newly discovered variant has enriched the mutational spectrum of the CREBBP gene and illustrated that WES is an efficient tool for the prenatal diagnosis of RSTS.