A prevalent mutation for galactosemia among black Americans.
J Pediatr
; 128(1): 89-95, 1996 Jan.
Article
em En
| MEDLINE
| ID: mdl-8551426
OBJECTIVE: To define the mutation causing galactosemia in patients of black American origin who have no galactose-1-phosphate uridyltransferase (GALT) activity in erythrocytes but good clinical outcome. METHODS: We discovered a mutation caused by a C-->T transition at base-pair 1158 of the GALT gene that results in a serine-to-leucine substitution at codon 135 (S135L). We developed a method with which to screen populations for its prevalence. We compared galactose-1-phosphate uridyltransferase among erythrocytes, leukocytes, and transformed lymphoblasts, as well as total body oxidation of D-(13C)-galactose to 13CO2 among three genotypes for GALT (S135L/S135L, Q188R/Q188R, and Normal/Normal). RESULTS: We found a 48% prevalence of the S135L mutation among 17 black American patients with classic galactosemia and a 1% prevalence in a population of 50 black Americans without galactosemia. The S135L mutation was not found in 84 white patients with G/G galactosemia nor in 87 white control subjects without galactosemia. We found normal whole body oxidation of D-(13C)-galactose by the patient homozygous for S135L and various degrees of enzyme impairment among different tissues. CONCLUSIONS: The S135L mutation in the GALT gene is a prevalent cause of galactosemia among black patients. Because GALT activity varies in different tissues of patients homozygous for S135L, they may have a better clinical outcome than patients who are homozygous for Q188R when both are treated from infancy.
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Bases de dados:
MEDLINE
Assunto principal:
UTP-Hexose-1-Fosfato Uridililtransferase
/
Mutação Puntual
/
População Negra
/
Galactosemias
Tipo de estudo:
Prevalence_studies
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Risk_factors_studies
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Screening_studies
Limite:
Female
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Humans
/
Newborn
Idioma:
En
Revista:
J Pediatr
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Estados Unidos