This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Channelopathies and Neuropathies, Subject name: Medicine
[{'content': 'A 14-year-old boy presents with bilateral foot deformity. On examination thickened peripheral nerves and sensory gait ataxia is observed. On biopsy of the nerve, a typical onion bulb appearance is noted. The probable diagnosis is? \nSelect and explain. \nA. Friedreich ataxia, B. Ataxia telangiectasia, C. Charcot Marie Tooth disease, D. Leprosy', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Image shows presence of Pes Cavus which indicates distal muscle weakness. Concomitant sensory deficit leads to Gait ataxia. Nerve biopsy: Classical onion bulb appearance s/o Charcot Marie Tooth disease. Charcot Marie Tooth disease ( Hereditary sensorimotor neuropathy) manifests as: Peroneal muscle dystrophy Stork leg appearance Thickened nerves N. biopsy: Onion bulb appearance Distal weakness ( Flexion contractures)', 'role': 'assistant'}]