Crigler-Najjar syndrome in The Netherlands: identification of four novel UGT1A1 alleles, genotype-phenotype correlation, and functional analysis of 10 missense mutants.
Hum Mutat
; 31(1): 52-9, 2010 Jan.
Article
em En
| MEDLINE
| ID: mdl-19830808
ABSTRACT
Crigler-Najjar syndrome (CN), caused by deficiency of UGT isoform 1A1 (UGT1A1), is characterized by severe unconjugated hyperbilirubinemia. In this study we have analyzed 19 CN patients diagnosed in The Netherlands (18) and in Belgium (1), and have identified 14 different UGT1A1 mutations, four of which are novel. Two mutations were present in several unrelated patients, suggesting the presence of two founder effects in The Netherlands. In addition, we show linkage of the UGT1A1 *28 promoter polymorphism (rs5719145insTA) to three structural mutations. Functional studies of partial active UGT1A1 mutants are limited. Therefore, we performed in vitro studies to determine the functional activity of seven missense mutants identified in this study and of three reported previously. In addition to bilirubin, we also determined their activity toward eight other UGT1A1 substrates. We demonstrate that five mutants have residual activity that, depending on the substrate, varies from not detectable to 94% of wild-type UGT1A1 activity. The identification of four novel pathogenic mutations and the analysis of residual activity of 10 UGT1A1 missense mutants are useful for clinical diagnosis, and provides new insights in enzyme activity, whereas the identification of two founder mutations will speed up genetic counseling for newly identified CN patients in The Netherlands.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Glucuronosiltransferase
/
Mutação de Sentido Incorreto
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Síndrome de Crigler-Najjar
/
Alelos
Tipo de estudo:
Diagnostic_studies
Limite:
Adolescent
/
Adult
/
Animals
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Female
/
Humans
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Male
/
Middle aged
País/Região como assunto:
Europa
Idioma:
En
Revista:
Hum Mutat
Assunto da revista:
GENETICA MEDICA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Finlândia