[Genetic analysis of a Chinese family affected with α-dystroglycanopathy due to variant of B3GALNT2 gene].

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with recurrent fetal hydrocephalus. METHODS: A couple who had presented at the Affiliated Hospital of Putian College on March 3, 2021 was selected as the study subject. Following elective abortion, fetal tissue and peripheral blood samples were respectively obtained from the abortus and the couple, and were subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing. RESULTS: The fetus was found to harbor compound heterozygous variants of the B3GALNT2 gene, namely c.261-2A>G and c.536T>C (p.Leu179Pro), which were inherited from its father and mother, respectively.According to the guidelines of American College of Medical Genetics and Genomics, both variants were classified as pathogenic (PVS1+PM2_Supporting; PM3+PM2_Supporting+PP3+PP4). CONCLUSION: The compound heterozygous variants of the B3GALNT2 gene probably underlay the α-dystroglycanopathy in this fetus. Above results have provided a basis for genetic counseling of this pedigree.