Wilson's disease (WD) is an autosomal recessive disorder of copper metabolism. The clinical phenotype of the disease is varied. It is proposed that this variation may be a result of differential functional disruption of ATPase7B (ATP7B) resulting from mutations in the gene ATP7B. We aimed to assess the relationship between specific mutational defects in ATP7B and divergence in the phenotypic expression of WD. One hundred and forty-two patients with clinically, biochemically and genetically diagnosed WD were included in the study. The phenotypic expression of WD was compared between patients with different types of mutations in ATP7B, detected by direct sequencing of exons 1-21 of the gene. Twenty-six mutations were identified in ATP7B; eleven of them were mutations predicted to result in the absence of a full-length normal protein [frameshift/nonsense mutations; classified as 'severe' mutations (SMs)], 14 were missense mutations (MMs) and one was a splice site mutation. Patients with one or two SMs on their alleles had lower serum copper and ceruloplasmin and were younger when the first symptoms of the disease appeared, compared with individuals with two MMs. The effect of SMs on the WD phenotype was dose-dependent. It is concluded that mutations within ATP7B are very heterogeneous. Frameshift and nonsense mutations are associated with a severe phenotype of WD.

Our investigations support the current hypothesis that NOD2/CARD15 mutations are associated with a phenotype of Crohn's disease with younger age at diagnosis, ileal involvement, ileocecal resections and a high risk of postoperative relapse and reoperation. NOD2/CARD15 mutations might therefore be used to identify high risk patients for relapse prevention strategies.

Wilson disease (WD) is a rare inherited autosomal recessive disorder caused by a defect in a metal transporting P-type ATPase, resulting in copper overload in various tissues and cells. The aim was to assess both the phenotype in Brazilian WD patients and the corresponding ATP7B genotype. Sixty subjects belonging to 46 pedigrees diagnosed as WD were included in this study. Direct sequencing of all 21 exons within ATP7B and their flanking introns was performed. Demographic, clinical, laboratory and histopathological data at the time of diagnosis were obtained. We identified twenty-five mutations, twelve of them reported for the first time. The c.3402delC mutation had the highest allelic frequency (30.8%), followed by the c.2123T>C (p.L708P) (16.7%). Exons 8 and 15 were the site of 62.5% of the mutations. The common European mutation c.3207C>A (p.H1069Q) was not present at all. Phenotype varied greatly among individuals with the same ATP7B genotype. Our data confirm the heterogeneity of ATP7B genotype in Brazilian WD patients. The mutational spectrum is compatible with the Brazilian history of Mediterranean immigration; however, new mutations, and different frequencies and phenotype associated with the previously known mutations characterize this population. Exons 8 and 15 should be preferentially screened in WD cases from Brazil. Phenotype variation among subjects with the same ATP7B genotype suggests that modifying factors play an additional role in the pathogenesis of WD.

We compared the effect of the p.H1069Q mutation and other non-p.H1069Q mutations in ATP7B on the phenotypic expression of Wilson's disease (WD), and assessed whether the clinical phenotype of WD in compound heterozygotes depends on the type of mutation coexisting with the p.H1069Q. One hundred forty-two patients with clinically, biochemically, and genetically diagnosed WD were studied. The mutational analysis of ATP7B was performed by direct sequencing. A total number of 26 mutations in ATP7B were identified. The p.His1069Gln was the most common mutation (allelic frequency: 72%). Seventy-three patients were homozygous for this mutation. Of compound heterozygotes, 37 had frameshift/nonsense mutation, and 20 had other missense mutation on one of their ATP7B alleles. Twelve patients had two non-p.H1069Q mutations. Patients homozygous for the p.H1069Q mutation had the less severe disturbances of copper metabolism and the latest presentation of first WD symptoms. The most severely disturbed copper metabolism and the earliest age at initial disease manifestation was noticed in non-p.H1069Q patients. In compound heterozygotes, the type of mutation coexisting with the p.H1069Q to a small extent influenced WD phenotype. The phenotype of WD varied considerably among patients with the same genotype. The p.H1069Q mutation is associated with late WD manifestation and with a mild disruption of copper metabolism. In compound heterozygotes, the phenotype of WD to a small extent depends on the type of mutation coexisting with the p.H1069Q. Besides genotype, additional modifying factors seem to determine WD manifestations.