Mutation screening and prenatal diagnosis of methylmalonic academia in a Chinese pedigree by Ion Torrent semiconductor sequencing

Abstract

To identify pathogenic mutations in a Chinese pedigree affected with methylmalonic academia for genetic counseling and prenatal diagnosis. Molecular analysis of the MUT, MMACHC, MMAA and MMAB genes was performed for the proband with methylmalonic academia by Ion Torrent semiconductor sequencing. Candidate mutations were validated by Sanger sequencing. The couple was offered prenatal diagnosis via analyzing of the fetal DNA through amniocentesis. The proband was found to be compound heterozygous for c.609G>A (p.Trp203X) and c.658-660del AAG (p.Lys220del) mutations, which were inherited respectively from each of his parents. Prenatal diagnosis showed that the fetus has inherited two wild-type parental alleles. The targeted Ion Torrent PGM sequencing has detected pathogenic mutations in the Chinese pedigree affected with methylmalonic academia, which has provided molecular evidence for clinical diagnosis, genetic counseling and prenatal diagnosis for the family.