This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Dystrophic gene mutation leads to \nSelect and explain. \nA. Myasthenia gravis, B. Duchenne Muscular Dystrophy, C. Motor neuron disease, D. Poliomyelitis', 'role': 'user'}, {'content': "Answer: B \nExplanation: Mutation in the Dystrophin gene leads to Duchene muscular dystrophy.\nBecker’s muscular dystrophy is also caused by a mutation in the dystrophin gene.\nMore questions on Duchenne’s muscular dystrophy\n\nIt is X-linked recessive disease\nClinical manifestation starts at 3-5 years of age\nLoss of muscle strength is progressive with a predilection for proximal limb muscles.*\nGowers' manoeuvre*\nOn getting up from the door the patient uses his hand to climb up himself.\nPseudohypertrophy of calf muscles is seen\nThe term pseudohypertrophy is used because it is not true hypertrophy of muscles (the muscle is replaced by fat\nand connective tissues)\nIntellectual impairment is common in Duchenne muscular dystrophy\nSerum creatinine phosphokinase levels are invariably elevated to 20-100 times normal.\nMuscle biopsy shows muscle fibres of varying sizes.", 'role': 'assistant'}]