<prompt> A 5-year-old male presented to AIIMS pediatrics OPD with a chief complaint of difficulty in climbing stairs and getting up from sitting position. There was history of maternal uncle having the same illness. On examination; there was pseudohypertrophy of calf muscle. Biopsy of the muscle was performed as shown below. What is your diagnosis?Duchenne muscular dystrophyMyotonic dystrophyFacioscapulohumeral muscular dystrophyNemaline myopathy  <response>: Ans. a Duchenne muscular dystrophyThis is myopathy with X-linked inheritance suggested by same history in maternal uncle. On muscle biopsy prominent variation in size of muscle fibers can be seen. 