Mutation analysis of ATP7B gene in Turkish Wilson disease patients: identification of five novel mutations.

Wilson disease is an autosomal recessive disorder of copper metabolism caused by mutations in the ATP7B gene that encodes a P-type copper transporting ATPase. The aim of this study was to screen and detect mutations of the ATP7B gene in unrelated Turkish Wilson disease patients (n = 46) and control group (n = 52). Mutations were screened and detected by DNA sequencing. 30 out of 46 patients had mutations. 24 different Wilson disease related mutations were identified in those patients. The distribution of mutations in ATP7B gene was as follow: 17 missense, 3 nonsense, 1 silent, 3 frameshift (1 insertion, 2 deletion). None of them were not found in the control group. Five out of 24 mutations were found to be novel. Four of them were missense (c.2363C > T, c.3106G > A, c.3451C > T, c.3733C > A). The last one was deletion (c.3111delC). 10 single nucleotide polymorphisms (SNPs) given in the literature were found in both control and patients groups. Moreover one new polymorphism in exon 18 (c.3727G > A) not reported previously was discovered in both groups. It was striking that most of the mutations were found in exons 8, 12-14. This is the first study covering Turkish Wilson disease patients and control groups for mutation screening in all the coding regions of ATP7B gene by DNA sequencing method and adding five new mutations and one polymorphism into the HUGO Wilson disease mutation database.