Mutation analysis of Taiwanese Wilson disease patients.
Wilson disease (WD) is an autosomal recessive disorder of copper metabolism, which is caused by mutation in copper-transporting ATPase (ATP7B). In the present study, we report a molecular diagnosis method to screen the WD chromosome in patients or in heterozygotic carriers in Taiwan. Exons 8, 11, 12, 13, 16, 17, and 18 of ATP7B are selected for the screening of mutations. The most common mutation, Arg778Leu or Arg778Gln, was first screened by PCR-RFLP then we combined single-stranded conformation polymorphism (SSCP) analysis followed by direct DNA sequencing on the DNA fragments with mobility shift on SSCP analysis. The diagnostic rate was compared with standard ATP7B whole gene sequencing analysis. Ten different mutations were identified among 29 WD patients; among them four were novel (Ala1168Pro, Thr1178Ala, Ala1193Pro, and Pro1273Gln). The false positive rates were tested against 100 normal individuals and listed as follows: exon 8: 5%; exon 11: 4%; exon 12: 6%; exon 13: 5%; exon 16: 5%; exon 17: 3%; exon 18: 4%. The Arg778Leu mutation exhibited the highest allelic frequency (43.1%). The detection rate of WD chromosomes is 65.52%, which is as sensitive as whole gene sequencing scanning. According to our results, WD chromosomes in Taiwan are predominantely located at exons 8, 11, 12, 13, 16, 17, and 18. The standard sequencing analysis on the entire gene is time consuming. We recommend screening these 7 exons first on those individuals who have a higher risk in having WD, before whole gene and promoter sequencing analysis in Taiwan.
Wan
Lei
L
Department of Medical Research, China Medical University Hospital, Taichung, Taiwan.
Tsai
Chang-Hai
CH
Tsai
Yuhsin
Y
Hsu
Chin-Moo
CM
Lee
Cheng-Chun
CC
Tsai
Fuu-Jen
FJ
D000251:Adenosine Triphosphatases / Q000235:genetics*; D000483:Alleles; D001120:Arginine / Q000235:genetics; D001483:Base Sequence; D004252:DNA Mutational Analysis; D005091:Exons / Q000235:genetics*; D005189:False Positive Reactions; D005787:Gene Frequency; D006580:Genetic Carrier Screening; D005973:Glutamine / Q000235:genetics; D006527:Hepatolenticular Degeneration / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D007930:Leucine / Q000235:genetics; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D017422:Sequence Analysis, DNA; D013624:Taiwan / Q000453:epidemiology
D005973:Glutamine; D001120:Arginine; D000251:Adenosine Triphosphatases; D007930:Leucine