Wilson's disease (WD) is an autosomal recessive disorder of copper metabolism caused by a large number of different mutations in the ATP7B gene. R778L mutation is mostly observed in Chinese, Japanese and Korean patients, whereas the H1069Q point mutation in the ATP7B gene is the most frequent mutation in European patients with WD. In our previous study we did not find a significant correlation between genotype and phenotype (age of onset and clinical presentation) in patients homozygous (37 patients) or heterozygous (52 patients) for R778L. It was reported that European patients homozygous for H1069Q who were also homozygous for the ApoE genotype epsilon3/3 developed clinical symptoms 5-11 years later than did patients with genotypes other than ApoE epsilon3/3. In the present study (i) we firstly observed that ApoE epsilon3/3 did not delay the onset of WD; (ii) no association between ApoE genotype and WD clinical presentation in Chinese Han children, including those patients homozygous for R778L. Thus we conclude that the onset of WD in Chinese children is not related to ApoE epsilon3/3, although the high frequency of ApoE epsilon3/3 in Chinese Han children with WD was not significantly different from that in controls.