[Mutation analysis and prenatal diagnosis for a pedigree affected with maple syrup urine disease].

Objective: To carry out mutation analysis for a pedigree affected with maple syrup urine disease (MSUD).
Methods: Clinical data of the proband was collected. Potential mutations of the BCKDHA and BCKDHB genes were analyzed by PCR and Sanger sequencing. Prenatal diagnosis was provided to a high-risk fetus at 12th gestational week through chorionic villus sampling.
Results: Two heterozygous mutations c.284G>C (p.Gly95Ala) and c.853C>T (p.Arg285*) of the BCKDHB gene were identified in the proband, which were inherited from his mother and father, respectively. Among these, c.853C>T (p.Arg285*) was known to be pathogenic, while c.284G>C (p.Gly95Ala) was a novel mutation. Prenatal diagnosis showed that the fetus has inherited the c.284G>C (p.Gly95Ala) mutation from its mother but no mutation from its father. After birth, the infant appeared to be healthy.
Conclusion: The compound heterozygous mutations c.284G>C (p.Gly95Ala) and c.853C>T (p.Arg285*) probably underlie the pathogenesis of MUSD in the proband. Mutation analysis can facilitate prenatal diagnosis and genetic counseling for the affected families.