A nonsense mutation (R242X) in the branched-chain alpha-keto acid dehydrogenase E1alpha subunit gene (BCKDHA) as a cause of maple syrup urine disease. Mutations in brief no. 160. Online.
Mutation analysis of DNA from cultured amniocytes with absent branched-chain alpha-ketoacid dehydrogenase activity revealed a C to T transition producing a nonsense mutation (R242X) in exon 7 of the gene encoding the E1a subunit of this multienzme complex (BCKDHA). This pregnancy occured in a large consanguinous pedigree with mutiple individuals with maple syrup urine disease (MSUD). PCR amplification of the region surrounding exon 7 allowed the identification of this mutation as well as two other previously identified mutations which cause MSUD.
Chinsky
J
J
Division of Human Genetics, Departments of Pediatrics and Obstetrics/Gynecology, and Department of Microbiology/Immunology, University of Maryland School of Medicine, Baltimore, MD, USA. jchinsky@welchlink.welch.jhu.edu
Appel
M
M
Almashanu
S
S
Costeas
P
P
Ambulos
N
N
Carmi
R
R
D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D001120:Arginine / Q000235:genetics; D003241:Consanguinity; D006801:Humans; D007658:Ketone Oxidoreductases / Q000235:genetics*; D008375:Maple Syrup Urine Disease / Q000201:enzymology / Q000235:genetics*; D009097:Multienzyme Complexes / Q000235:genetics*; D020125:Mutation, Missense / Q000235:genetics*; D010375:Pedigree
D009097:Multienzyme Complexes; D001120:Arginine; D007658:Ketone Oxidoreductases; D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)