Prenatal diagnosis of a de novo 17q25.3 microdeletion encompassing RAC3 and CSNK1D in a fetus associated with partial agenesis of the corpus callosum, small brain volume, micrognathia and total anomalous pulmonary venous return.

Objective: We present prenatal diagnosis of a de novo 17q25.3 microdeletion in a fetus with abnormalities of the brain, heart and face.

Case Report: A 32-year-old, gravida 2, para 1, woman underwent amniocentesis at 25 weeks of gestation because of fetal abnormalities of partial agenesis of the corpus callosum with absence of the splenium, small brain volume, colpocephaly and micrognathia on fetal magnetic resonance imaging (MRI) and total anomalous pulmonary venous return (TAPVR) and partial agenesis of the corpus callosum on fetal ultrasound at 23 weeks of gestation. Amniocentesis revealed a karyotype of 46,XY, and simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes showed arr [GRCh37 (hg19)] 17q25.3 (79,838,999-80,426,634) × 1.0 with a 587.64-kb 17q25.3 microdeletion encompassing 23 OMIM genes including RAC3 and CSNK1D. The parental bloods did not have such a microdeletion. The pregnancy was subsequently terminated, and a malformed fetus was delivered with facial dysmorphism of abnormal head shape, low-set ears, micrognathia, depressed nasal bridge and hypertelorism. aCGH analysis on the cord DNA confirmed the prenatal diagnosis of a 17q25.3 microdeletion.

Conclusion: A 17q25.3 microdeletion encompassing RAC3 and CSNK1D may present abnormalities of the brain, heart and face on fetal imaging.