Characterization of the Prenatal Ultrasound Phenotype Associated With 7q11.23 Microduplication Syndrome and Williams–Beuren Syndrome

ABSTRACT Objective This study aimed to characterize the intrauterine phenotype of fetuses with 7q11.23 microduplication syndrome and Williams–Beuren syndrome (WBS) to provide insight into prenatal genotype and phenotype correlations in the 7q11.23 region. Methods Seven fetuses with 7q11.23 microduplication syndrome and sixteen with WBS were diagnosed via array comparative genomic hybridization (array CGH) or copy number variation sequencing (CNV‐seq) at our center. Clinical data were also systematically collected and analyzed, including intrauterine phenotype, pregnancy outcome, and inheritance. Results In our cases, the most common prenatal ultrasound feature of 7q11.23 microduplication syndrome was cardiovascular defects; less frequent features included choroid plexus cysts, anencephaly, bilateral pyelectasis, and cervical lymphatic hygroma. On the other hand, WBS was mainly associated with cardiovascular defects and intrauterine growth retardation. Other clinical phenotypes included hypoechoic frontal horn of the right lateral ventricle, crossed fused renal ectopia, hyperechogenic bowel, hyperechogenic right thoracic cavity, and hyperechogenic hepatic parenchyma/intrahepatic duct wall. Conclusions Our study describes a series of new ultrasound features identified prenatally in fetuses with 7q11.23 microduplications and microdeletions with the intent of expanding the prenatal phenotype associated with copy number variants in this chromosomal region. Additional studies are needed to clearly delineate specific prenatal features associated with these rare genetic entities.