Novel mutations in Uridyl-diphosphate-glucuronosyl-transferase 1A1 (UGT1A1) gene in Tunisian patients with unconjugated hyperbilirubinemia.

Autor: Trabelsi N; Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire d'Hématologie Moléculaire et Cellulaire, Tunisie. Electronic address: nawel.trabelsi@pasteur.utm.tn., Chaouch L; Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire d'Hématologie Moléculaire et Cellulaire, Tunisie; Université de Sousse, Faculté de Médecine de Sousse, Tunisie., Haddad F; Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire d'Hématologie Moléculaire et Cellulaire, Tunisie., Jaouani M; Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire d'Hématologie Moléculaire et Cellulaire, Tunisie., Barkaoui E; Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire d'Hématologie Moléculaire et Cellulaire, Tunisie., Darragi I; Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire d'Hématologie Moléculaire et Cellulaire, Tunisie., Chaouachi D; Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire d'Hématologie Moléculaire et Cellulaire, Tunisie., Boudrigua I; Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire d'Hématologie Moléculaire et Cellulaire, Tunisie., Menif S; Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire d'Hématologie Moléculaire et Cellulaire, Tunisie., Abbes S; Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire d'Hématologie Moléculaire et Cellulaire, Tunisie.
Jazyk: angličtina
Zdroj: European journal of medical genetics [Eur J Med Genet] 2021 Feb; Vol. 64 (2), pp. 104139. Date of Electronic Publication: 2021 Jan 07.
DOI: 10.1016/j.ejmg.2021.104139
Abstrakt: Introduction: Unconjugated hyperbilirubinemia (UCB) is a feature of Gilbert's syndrome (GS) and Crigler-Najjar's syndrome (CNS), which are two hereditary defects in bilirubin metabolism. Both syndromes are linked to mutations in the UGT1A1 gene, which cause either the decrease or the absence of the UGT1A1 enzymatic activity. Here, we investigated the molecular basis of the UGT1A1 gene in Tunisian patients presenting with unconjugated hyperbilirubinemia.
Methods: Twenty-four patients with UCB were investigated. The screening protocol for hemoglobinopathies, enzymopathies, and membrane defects was executed in all patients. Afterward, the molecular analysis of the entire UGT1A1 gene was performed by DNA Sanger sequencing. Several bioinformatic tools were used to explore the effects of novel mutations.
Results: Fifteen different UGT1A1 variations were identified, among which four are described here for the first time. In exon 5, the c.1412C > G; p.(Ala471Gly) and c.1589C > T; p.(Ser530Phe) mutations were detected in patients presenting with CNS type I and GS, respectively. In the 3'UTR region of UGT1A1, the c.*90C > T mutation was detected in 3 patients with CNS type I. In the same region, the c.*388C > T defect was found in a GS patient. A deleterious and damaging effect on the UGT1A1 protein were predicted for both exonic mutations. Furthermore, novel microRNAs were identified as targetting the mutated sequences for the 3'UTR mutations.
Conclusion: Our study provides novel data on UCB among Tunisians. Furthermore, we report four novel mutations associated with both GS and CNS. The identification of these mutations increases the spectrum of the UGT1A1 mutations and contributes to an understanding of the molecular abnormalities associated with unconjugated hyperbilirubinemia.
(Copyright © 2021 Elsevier Masson SAS. All rights reserved.)
Databáze: MEDLINE
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