EP04.13: Parental origin of autosomal trisomies and triploidies prenatally diagnosed by QF‐PCR

Abstract

Array was normal male. Turbo WES revealed a homozygous pathogenic c.964-1G>C mutation in the 7-dehydrocholesterol reductase (DHCR7 )gene known to cause the autosomal recessive Smith-Lemli-Opitz syndrome. The parents decided for termination of the pregnancy. Obduction of the fetus showed an ambiguous gender with a vagina and micropenis, previously described facial dysmorphism, anomalies of the extremities and heart, partial agenesis of the corpus callosum and bilateral hypoplastic kidneys. Microscopy of the gonads showed male gonads with reduced number of tubuli seminiferi.The best diagnostic clues for SLOS is the combination of early onset severe FGR, polydactyly / syndactyly, genital ambiguity and various anomalies in brain, heart and kidneys. Identification of mutations in DHCR7 in affected pregnancies allows carrier detection and future preimplantation and prenatal diagnosis. EP04.13Parental origin of autosomal trisomies and triploidies prenatally diagnosed by QF-PCR