Whole exome sequencing aids the diagnosis of Simpson–Golabi–Behmel syndrome in two male fetuses

OBJECTIVE: To diagnose and explore the genetic aetiology of Simpson–Golabi–Behmel syndrome type 1 (SGBS1) in two male fetuses. METHODS: Prenatal ultrasound scans and further genetic analysis using karyotype analysis, chromosomal microarray analysis, whole exome sequencing (WES) and Sanger sequencing were conducted. RESULTS: Prenatal ultrasound scans of two fetuses showed multiple congenital anomalies and hydramnios. Subsequent to termination of the pregnancies, a novel nonsense variant (c.892G>T, p.E298*) in the glypican 3 (GPC3) gene of the two fetuses was identified by WES and further confirmed by Sanger sequencing. The two fetuses were diagnosed with SGBS1. The mother was heterozygous for the c.892G>T variant. CONCLUSION: This study describes the prenatal sonographic features of SGBS1, emphasizes the role of WES in the diagnosis of SGBS1 and expands the known mutation spectrum of the GPC3 gene.