Objective: To carry out genetic analysis for 3 children from two Chinese families affected with maple syrup urine disease (MSUD).
Methods: Target capture - next-generation sequencing and Sanger sequencing were used to detect pathogenic variants associated with MSUD.
Results: The proband from family 1 was found to harbor homozygous c.560G>T (p.Gly187Val) variant of the BCKDHB gene (NM_000056), whilst the two patients from family 2 were found to harbor compound heterozygous variants c.197-2A>G (splicing)/c.218delT (p.F74Sfs*4) of the BCKDHB gene. Among these, the c.560G>T and c.218delT variants were unreported previously.
Conclusion: The new variants discovered in this study have expanded the mutational spectrum of the BCKDHB gene.