A 15-year-old girl is seen by a dermatologist for removal of multiple squamous cell carcinomas of the skin. The patient has nearly white hair, pink irises, very pale skin, and a history of burning easily when exposed to the sun. This patient's condition is caused by a disorder involving which of the following substances?
A. Aromatic amino acids
B. Branched chain amino acids
E. Sulfur-containing amino acids