Novel prenatally diagnosed compound heterozygous POMT2 variants in fetal congenital primary aqueduct stenosis

ObjectiveTo study the etiology of congenital hydrocephalus in genetic aqueduct stenosis.Case reportWe report the case of a 31-year-old pregnant female, G2P0A1, with a history of hyperthyroidism under medical control. The patient received regular prenatal care, with no specific findings in the Level II ultrasound at 21 weeks of gestation. However, hydrocephalus was noted at GA 31 weeks. High-resolution sonography and fetal magnetic resonance imaging (MRI) reported fetal aqueduct stenosis. Maternal HSV, CMV, and toxoplasma infection were not detected. Fetal karyotype and chromosomal microarray analysis (CMA) indicated a normal. After intensive counseling, the parents decided to terminate the pregnancy due to the poor fetal prognosis. Post-mortem, a whole-exome sequencing (WES) and Sanger sequencing analysis trio study identified two compound heterozygous variants in the POMT2 gene inherited from both recessive parents. In the subsequent pregnancy, a WES survey revealed inheritance of only the maternal POMT2 gene variant; a live, healthy male baby was born.ConclusionExtended WES represents a precision maternal medicine tool for novel prenatal diagnosis of congenital aqueduct stenosis.