Molecular genetic analysis of exon 3 of the ATP7B gene in Cuban patients with Wilson’s disease

Abstract

Introduction: Wilson's disease is a rare inherited autosomal recessive disorder caused by mutations in the ATP7B gene. The exon 3 of the ATP7B gene is polymorphic, and more than 120 polymorphisms of this type have been reported in the literature.

Objective: To identify conformational band shifts in exon 3 and detect polymorphisms of the ATP7B gene in Cuban patients, clinically diagnosed with Wilson's disease.

Material and Methods: A descriptive study including 105 patients with the clinical diagnosis of Wilson's disease was conducted at the National Center for Medical Genetics and the National Institute of Gastroenterology from 2007 to 2013.  Salting-out protocol was used for DNA extraction. The Polymerase Chain Reaction was used to amplify the fragment of interest and the Single-Strand Conformational Polymorphism was   applied in the region of exon 3 of the ATP7B gene to identify conformational changes and the presence of the polymorphism p.L456V.

Results: The conformational change called B and C corresponded to the p.L456V polymorphism in the heterozygous and homozygous states, respectively. The allelic frequency of the p.L456V polymorphism in 105 Cuban patients clinically diagnosed with Wilson's disease was 41 %.  The most common manifestations in patients with this polymorphism were related to the liver.

Conclusions: The p.L456V polymorphism was identified in 64 Cuban patients with Wilson disease, which will enable us to conduct molecular studies by indirect methods.

Keywords: Wilson disease, polymorphism, exon 3, SSCP, Polymerase Chain Reaction, salting-out.