Application of Biotechnology in Detection ATP7B Gene Mutation in Vietnamese Children with Wilson Disease and Screening Target Mutation for Their Family Members

Abstract

Background/Purpose: Wilson’s disease (WD) is an autosomal recessive disorder of the copper metabolism, which is caused by a mutation in the copper-transporting P-type ATPase (ATP7B). The mechanism of this disease is the failure of hepatic excretion of copper to bile, and leads to copper deposits in the liver and other organs. The ATP7B gene is located on the long arm of chromosome 13 (13q14.3). This study aimed to investigate the gene mutation in the Vietnamese patients with WD, and make a asymptomatic diagnosis for their familial members.
 Methods: Forty-three WD patients and their 67 siblings were identified as having ATP7B gene mutations. Genomic DNA was extracted from peripheral blood samples; 21 exons and exon-intron boundaries of the ATP7B gene were analyzed by direct sequencing.
 Results: A total of 27 different mutations were detected in this study, which accounted for 96.8%. Of which, S105* was the most prevalent mutation, accounting for 37.1%. Following was the five other mutations, including I1148T (7.3%), IVS14-2A>G (6.6%), L1371P (6.0%), T850I and V176SfsX28 (5.3%). Among 47 genotypes, ratio of compound heterozygote was 62.8%. Most of the mutations in the study occurred in exon 2 (43.0%), exon 16 (9.9%), exon 8 (8.6%), exon 14 and intron 14 (6.6%). A total of 13 affected siblings were identified by target mutation on ATP7B gene which was identified in the proband. Among them, 5 cases were asymptomatic that would be treated soon to prevent clinical feature. This study also discoved 65 carriers in their family members.
 Conclusion: The findings’ highest diagnostic importance for patients and their family members is in prognosis and the prevention of morbidity and mortality.