Wilson disease (WD) is an autosomal recessive disorder of copper transport, resulting in copper accumulation and toxicity to the liver and brain. The gene (WD) has been mapped to chromosome 13 q14.3. On yeast artificial chromosomes from this region we have identified a sequence, similar to that coding for the proposed copper binding regions of the putative ATPase gene (MNK) defective in Menkes disease. We show that this sequence forms part of a P-type ATPase gene (referred to here as Wc1) that is very similar to MNK, with six putative metal binding regions similar to those found in prokaryotic heavy metal transporters. The gene, expressed in liver and kidney, lies within a 300 kb region likely to include the WD locus. Two WD patients were found to be homozygous for a seven base deletion within the coding region of Wc1. Wc1 is proposed as the gene for WD.

We have previously reported the cloning of a gene that encodes a copper transporting P-type ATPase (ATP7B) which is defective in Wilson disease. We have now identified in 58 WND patients, 20 new mutations as well as three of five previously published mutations: 11 small insertions and deletions, seven missense, two nonsense and three splice site mutations. Two of the mutations are relatively frequent, representing 38% of the mutations in patients of European origin. Our findings suggest a wider spectrum of age of onset than is considered typical of Wilson disease: mutations that completely disrupt the gene can produce liver disease in early childhood when Wilson disease may not typically considered in the differential diagnosis. The mutations identified provide an explanation for at least part of the wide phenotypic variation observed in Wilson disease.

The major cause of death in cystic fibrosis (CF) is chronic lung disease associated with persistent infection by the bacterium, Pseudomonas aeruginosa. S100A8, an S-100 calcium-binding protein with chemotactic activity, is constitutively expressed in the lungs and serum of CF patients. Levels of S100A8 mRNA were found to be three to four times higher in the lungs of mice carrying the G551D mutation in CF transmembrane conductance regulator compared with littermate controls. Intravenous injection of bacterial LPS induced S100A8 mRNA in the lung to a greater extent in G551D mice than in wild-type littermates. Localization of S100A8 mRNA and protein in the lung indicate that it is a marker for neutrophil accumulation. Bone marrow-derived macrophages from G551D mice were shown to also exhibit hypersensitivity to LPS, measured by induction of TNF-α. These results provide evidence that the pathology of CF relates to abnormal regulation of the immune system.