Analysis of the UDP-glucuronosyltransferase gene in Portuguese patients with a clinical diagnosis of Gilbert and Crigler–Najjar syndromes

• Autor(a) principal: Costa, Elísio
• Data de Publicação: 2006
• Outros Autores: Vieira, Emília, Martins, Marcia, Saraiva, Jorge A., Cancela, Eugénia, Costa, Miguel, Bauerle, Roswitha, Freitas, Teresa R., Carvalho, João, Santos-Silva, Ermelinda, Barbot, José, Santos, Rosário
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/491
• topic: Gilbert syndrome; UGT1A1; Crigler–Najjar syndrome; Hyperbilirubinemia; Mutations

We describe the molecular study in a cohort of 120 Portuguese patients with the clinical diagnosis of Gilbert syndrome and in one with the diagnosis of Crigler–Najjar syndrome type II, as well as a prenatal diagnosis of Crigler–Najjar syndrome type I. Among the 120 unrelated patients with Gilbert syndrome, 110 were homozygous for the [TA]7 allele ([TA]7/[TA]7), and one patient was a compound heterozygote for two different insertions ([TA]7/[TA]8). The remaining 9 patients were heterozygous for the TA insertion ([TA]6/[TA]7). Additional studies in these 9 patients revealed heterozygosity for the c.674T>G, c.488_491dupACCT and c.923G>A mutations, in 1, 1 and 4 patients, respectively. The patient with Crigler–Najjar syndrome type II was a compound heterozygote for [TA]7 and the c.923G>A mutation. The undocumented polymorphisms c.-1126C>T and c.997-82T>C were also detected in the course of this study. Prenatal diagnosis in a family with a boy previously diagnosed as Crigler–Najjar syndrome type I and homozygosity for the c.923G>A mutation revealed that the fetus was unaffected. Homozygosity for the [TA] insertion was found to be the most frequent cause of GS in our population. Identification of further mutations in the UGT1A1 gene was also seen to contribute significantly towards diagnosis.