The paper by Vrabelova et al. reflects a comprehensive genetic approach in characterizing genetically patients with Wilson disease (WD). They studied mutations within ATP7B-the gene encoding the defective WD protein ATPase 7B-in 227 WD patients from 200 unrelated Czech and Slovak families, which represents a very large cohort for WD, and therefore, the impact of their findings are highly important. There are accumulating papers published on mutations in WD, but besides reporting new mutations, mostly the genetic analysis is presented by sequencing data of limited exon analysis and the lack of additional screening techniques used. This in turn complicates the current interpretation of the reported mutations within ATP7B and the role of genetic testing for WD in general. The real distribution of mutations within ATP7B are not well established, there is limited information on the mutational detection rate, and there is still little known on the promoter region of ATP7B.