In Wilson disease, there is a wide variety in phenotypic presentation, even in patients with the same mutations in ATP7B. Several studies into possible modifier genes were executed and several candidate polymorphisms are thought to modify the clinical phenotype, including COMMD1 [8], ATOX1 [9], PNPLA3 [10], MTHFR [11], XIAP [12], and DMT1 [13]. This evidence concerns the gene ATP7B and Wilson disease.