Identification of a high frequency of mutation at exon 8 of the ATP7B gene in a Chinese population with Wilson disease by fluorescent PCR.
BACKGROUND: Wilson disease (WD) is an autosomal recessive disorder of copper transport. Mutation analysis has led to the discovery of more than 100 mutations at ATP7B, and most of them are population specific. OBJECTIVES: To verify the high frequency of mutation at exon 8 of ATP7B in Chinese patients with WD and to establish a DNA diagnostic method for WD. SETTING: University medical centers. PATIENTS AND METHODS: Screening for mutations at exon 8 of ATP7B by fluorescent polymerase chain reaction analysis and restriction analysis was conducted in 106 unrelated Chinese patients with WD and in 55 individuals from 10 Chinese families with WD. RESULTS: Five homozygotes and 32 heterozygotes were identified. Sequence analysis showed a missense mutation (2273G-->T) and a nonsense mutation (2250C-->G) together at exon 8. The rate of gene mutation in 106 patients was 35% (5% homozygous and 30% heterozygous). Samples of DNA from 55 individuals from 10 Chinese families with WD were examined by fluorescent polymerase chain reaction. We found that 13 siblings were carriers (24%). CONCLUSIONS: A high frequency of mutation at exon 8 of the ATP7B gene exists in the Chinese population, and fluorescent polymerase chain reaction analysis may be an effective and accurate assay in detection of the WD gene.