Modifying genes proposed to be associated with WD include esterase D (ESD), INO80 chromatin remodeling complex, apolipoprotein (APOE), methyl-CpG Binding Domain Protein 6 (MBD6), patatin-like phospholipase domain-containing 3 gene (PNPLA3), and methylenetetrahydrofolate reductase (MTHFR). Here, PNPLA3 is linked to Wilson disease.