<prompt> Dystrophic gene mutation leads toMyasthenia gravisDuchenne Muscular DystrophyMotor neuron diseasePoliomyelitis  <response>: Mutation in the Dystrophin gene leads to Duchene muscular dystrophy.Beckers muscular dystrophy is also caused by a mutation in the dystrophin gene.More questions on Duchennes muscular dystrophyIt is X-linked recessive diseaseClinical manifestation starts at 3-5 years of ageLoss of muscle strength is progressive with a predilection for proximal limb muscles.Gowers manoeuvreOn getting up from the door the patient uses his hand to climb up himself.Pseudohypertrophy of calf muscles is seenThe term pseudohypertrophy is used because it is not true hypertrophy of muscles the muscle is replaced by fatand connective tissuesIntellectual impairment is common in Duchenne muscular dystrophySerum creatinine phosphokinase levels are invariably elevated to 20-100 times normal.Muscle biopsy shows muscle fibres of varying sizes. 