Prenatal ultrasound findings in Koolen‐de Vries foetuses: Central nervous system anomalies are frequent markers of this syndrome

Objective Prenatal diagnoses of microdeletion syndromes without ultrasound findings in the first and second trimester are always difficult. The objective of this study is to report the prenatal ultrasound findings in four foetuses diagnosed with 17q21.31 microdeletions (Koolen‐de Vries syndrome) using chromosomal microarrays (CMA). Patients and Methods We present four foetuses with 17q21.31 microdeletion. All showed CNS anomalies in the third trimester, three had ventriculomegaly, and one hypogenesis of corpus callosum at 31 weeks of pregnancy. Results Array‐SNPs and CGH‐array were performed on uncultured amniocytes and peripheral blood revealing a 17q21.31 microdeletion. Conclusions Prenatal CNS anomalies (mainly ventriculomegaly) at third trimester, in spite of isolate, should be considered a prenatal ultrasound marker of this syndrome. This kind of malformations raise the possibility of an underlying genetic conditions including 17q21.31 microdeletion; thus, CMA should be taken into consideration when offering prenatal genetic counselling.
Prenatal CNS anomalies (mainly ventriculomegaly) at third trimester, should be considered a prenatal ultrasound marker of this syndrome. This kind of malformations raise the possibility of an underlying genetic condition including 17q21.31 microdeletion. Thus CMA should be taken into consideration when offering prenatal genetic counselling.