ATP7B and Wilson disease: Copper deficiency due to malfunction of ATP7A copper transporter encoded by mutated ATP7A gene [11-13] causes neurological disorder in Menkes disease [14], while accumulation of excess copper due to malfunction of ATP7B copper transporter encoded by mutated ATP7B gene [15-17] causes neurological disorder in Wilson’s disease (WD), or hepatolenticular neurodegeneration [18-21].