This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Amino acid Metabolism, Subject name: Pediatrics
Not a feature of Hanup's disease: 
Select and explain. 
A. Pellagroid skin lesion, B. Cerebellar ataxia, C. Mental retardation, D. Psychological disturbances
C: Mental retardation
Answer: C: Mental retardation 
Explanation: Hanup disease: Most children remain asymptomatic In symptomatic patient- cutaneous photosensitivity: pellagra-like rash on sun exposure Some patients may have intermittent ataxia & psychological disturbances, but mental development is usually normal.