Genetic Research Of Wilson's Disease

Objective:To detect of the ATP7B gene mutation type and mutation frequency in the Chinese Han patients with Wilson's disease (WD; hepatolenticular degeneration, HLD) from Hunan province.Methods:Direct sequencing of the polymerse chain reaction (PCR) products of 21 exons on the ATP7B gene was conducted in 9 Chinese Han family with WD and 100 normal controls.Results:1. The ATP7B gene mutations were identified in 9 WD families (2 homozygous mutations families and 7 compound heterozygous mutations families), and 11 mutations were found including 2 nonsense mutations (p.Glu388X and p.Gly837X), one deletion mutation (c.2659delG) and 8 missense mutations (p.Val145Phe, p.Thr498Ser, p.Asp765Gly, p.Arg778Leu, p.Gly869Arg, p.Pro992Leu, p.Ala1295Val and p.Arg1320Ser), of which p.Val145Phe, p.Glu388X, p.Thr498Ser and p.Gly837X were the new discovered mutations. Sixteen polymorphisms (p.Ser137Ser, p.Ser406Ala, p.Val456Leu, p.Phe763Phe, p.Leu770Leu, p.Arg832Lys, p.Val834Val, p.Arg952Lys, p.Val1140Ala, p.Val1297Ile, p.Leu1325Leu, p.Leu1333Leu, IVS8+26A/G, IVS8+27G/A, IVS18 +6T/C and IVS19+50G/C) were found at the same time genetic analysis of families, of which p.Ser137Ser, IVS8+26A/G, IVS8+27G/A, p.Phe763Phe, p.Val834Val, p.Leu1325Leu and p.Leu1333Leu were new discovered polymorphisms.2. Haplotype analysis were conducted in the families with the same mutations, and we found that different families shared with the same disease haplotypes (a common haplotype for Family M1279, Family M1524 and Family M2621; a common haplotype Family M41 and Family M1407; a common haplotype Family M1031, Family M1038 and Family M1623), suggesting possible founder effects.3. In our families, p.Arg778Leu mutation on exon 8 and p.Pro992Leu on exon 13 were all found in 33.3%(3/9) patients with WD. Mutation p.Ala1295Val on exon 18 was found in 22.2%(2/9) patients with WD. Mutations p.Val145Phe and p.Glu388X were mapped on exon 2, and mutations p.Gly869Arg and c.2659deIG were located on exon 11. Therefore, we suggest that exons 2,8,11,13 and 18 of the ATP7B gene may set as the prior screening exons for Chinese Han patients with WD from Hunan.Conclusions:1. The ATP7B gene mutations were identified in 9 WD families, including a total of 11 mutations and 16 polymorphisms, of which p.Val145Phe, p.Glu388X, p.Thr498Ser and p.Gly837X are new discovered mutations, and p.Ser137Ser, p.Phe763Phe, IVS8+26A/G, IVS8+27G/A, p.Val834Val, p.Leu1325Leu and p.Leu1333Leu are new discovered polymorphisms.2. Different families shared with the same disease haplotypes (a common haplotype for Family M1279, Family M1524 and Family M2621; a common haplotype Family M41 and Family M1407; a common haplotype Family M1031, Family M1038 and Family M1623), suggesting possible founder effects.3. Exons 2,8,11,13 and 18 on the ATP7B gene may be considered as mutation high frequency regions and regular screening sites for WD in the Chinese Han nationality from Hunan.