Maple syrup urine disease in Cypriot families: identification of three novel mutations and biochemical characterization of the p.Thr211Met mutation in the E1alpha subunit.
Genet Test Mol Biomarkers
; 13(5): 657-64, 2009 Oct.
Article
em En
| MEDLINE
| ID: mdl-19715473
ABSTRACT
We report five mutations, three of them novel, responsible for maple syrup urine disease in four unrelated Cypriot families. The five children studied are the first cases of classic maple syrup urine disease to be reported among Cypriots. The first novel mutation identified is a single-base deletion in exon 6 of the Elalpha gene (c.718delG), which leads to a frameshift after Ala240 and to a stop codon 89 residues further downstream. The other two novel mutations identified are in the Elbeta subunit a two-base deletion in exon 6, c.662_663delCC, which leads to a frameshift after Ala221 and creates a stop codon 17 residues further downstream, as well as a splice mutation, IVS3[+3]delA, which results in the skipping of exon 3. The two known mutations identified are in the Elalpha gene the G > C transversion at the 3'-splice acceptor site, (IVS5-1G > C), which results in the deletion of the entire exon 6, and the missense mutation in exon 5 (c.632C > T), which corresponds to a p.Thr211Met substitution. The p.Thr211Met substitution is located in a potassium-ion pocket in the E1 component required for stability of the bound cofactor thiamine diphosphate. The mutant E1 protein harboring the p.Thr211Met substitution was shown unable to bind thiamine diphosphate, leading to undetectable E1 activity.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Mutação da Fase de Leitura
/
3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)
/
Doença da Urina de Xarope de Bordo
Tipo de estudo:
Diagnostic_studies
Limite:
Humans
País/Região como assunto:
Europa
Idioma:
En
Revista:
Genet Test Mol Biomarkers
Assunto da revista:
BIOLOGIA MOLECULAR
/
GENETICA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Chipre