The correct answer is C. ATP7B gene.
The correct answer is the ATP7B gene (Choice 3), which is mutated in Wilson’s disease. In this condition, there is a defect in copper metabolism leading to deposition in the liver and subsequent liver failure. Cutaneous findings include Kayser-Fleischer rings (due to copper deposition in Descemet’s membrane), blue lunulae, and pretibial hyperpigmentation.
Phenylalanine hydroxylase (PAH) gene (Choice 1) is mutated in phenylketonuria. α-galactosidase A (GLA) gene (Choice 2) is mutated in Fabry disease. Glucocerebrosidase (GBA) gene (Choice 4) is mutated in Gaucher disease. Cystathionine β-synthase (CBS) gene (Choice 5) is mutated in homocystinuria.
Bolognia, Jean., Jorizzo, Joseph L.Schaffer, Julie V. (Eds.) (2012) Dermatology /[Philadelphia] : Elsevier Saunders