[Genotype and phenotype correlation in Chinese patients with Wilson's Disease].
OBJECTIVE
To determine distribution and mutation pattern of type P ATP7B gene mutation and to explore genotype and phenotype correlation in patients with Wilson's disease (WD).


METHODS
Sixty patients with WD from 57 no kinship families, 37 male and 23 female, were enrolled in this study. The age of onset ranged from 4.6 - 39 years, < or = 16 years in 55 patients. Some exons of ATP7B gene mutation were analyzed in patients with WD by using biochemical methods, polymerase chain reaction-single strand configuration polymorphism (PCR-SSCP), restriction fragment and DNA sequence analysis. Totally 778 coding regions were identified with restriction enzyme Msp I. The activity of Cu-ATPase was assessed by measuring inorganic phosphorus in 3 patients with known genotype.


RESULTS
Fifty-two of 60 patients (86%) had presented with hepatic manifestations, 30 of them had only hepatic manifestations, 12/52 patients had hepatic and neurological manifestations at the same time; 10/52 patients had hepatic and other symptom; 7/60 patients had only neurological symptom, one patient had no symptom. Eleven mutations were detected by DNA sequencing, including five missense mutations (R778L, V1140A,G943S, V1106I and V1216M), one deletion (1384del17) and five polymorphisms (IVS4-5T/C, A2495G, C2310G, IVS18 + 6C/T and IVS20 + 5A/G) were identified. R778L mutation was identified 52/114 alleles (45.6%). R778L occurred in 38/52 patients with hepatic manifestation (73%), homozygosis of R778L was demonstrated in 14 patients and heterozygosity of R778L in 24 patients. V1106I mutation was 1.7%, G943S, V1140A, and V1216M was 0.86% respectively in this study. Two patients with delayed onset of neurological symptoms occurred V1106I mutation of ATP7B. Cu-ATPase activity of 3 patients with known mutation (R778L/V1106I, R778L/V1216M and R778L/R778L) declined by 44.55%, 88.23% and 69.49%, respectively, compared with normal control.


CONCLUSIONS
The 1384del17bp and V1106I are two novel mutations found in patients with WD. R778L was common mutation of ATP7B gene with frequency of 45.6% in this study. The mutation in exon 8 of WD gene may play an important role in pathogenesis of WD in Chinese. Carriage of R778L mutation seems to be correlated with hepatic manifestation.
Liu
Xiao-qing
XQ
Department of Pediatrics, Xinhua Hospital, Shanghai Second Medical University and Shanghai Institute for Pediatric Research, Shanghai 200092, China.
Zhang
Ya-fen
YF
Liu
Tze-tza
TT
Gu
Xue-fan
XF
Hsiao
Kwang-jen
KJ
Bao
Ke-rong
KR
Yu
Li-hua
LH
D000251:Adenosine Triphosphatases / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D027682:Cation Transport Proteins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D000073840:Copper-Transporting ATPases; D004252:DNA Mutational Analysis; D005091:Exons; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006527:Hepatolenticular Degeneration / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D009154:Mutation; D010641:Phenotype; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D017422:Sequence Analysis, DNA
D027682:Cation Transport Proteins; D000251:Adenosine Triphosphatases; C000612464:ATP7B protein, human; D000073840:Copper-Transporting ATPases