You Are Examining a Pediatric Patient Brought to You by His

You are examining a pediatric patient brought to you by his parents because they are disturbed by his progressive mood changes and apparent hightened anxiety. Physical examination shows pellegra-like skin eruptions and signs of cerebellar ataxia that include unsteady gait and uncoordinated eye movements. Serum and urinalysis show significant aminoacidemia and aciduria. These signs and symptoms are most likely due to which of the following disorders?

A) alkaptonuria
B) glycine decarboxylase deficiency (GCC deficiency)
C) Hartnup disorder
D) maple syrup urine disease
E) PKU