188. A 3-year-old boy is brought to the physician because of a 6-month history of a sway back when standing. His brother had a history of muscle weakness and died of pneumonia at the age of 12 years. Physical examination shows hip girdle weakness. His serum creatine kinase concentration is markedly increased. This patient's symptoms are most likely caused by the accumulation of a defective protein in which of the following locations in muscle cells? A) Cytoplasm B) Lysosome C) Mitochondria D) Nuclear membrane E) Peroxisome F) Smooth endoplasmic reticulum h

188. A 3-year-old boy is brought to the physician because of a 6-month history of a sway back when standing. His brother had a history of muscle weakness and died of pneumonia at the age of 12 years. Physical examination shows hip girdle weakness. His serum creatine kinase concentration is markedly increased. This patient's symptoms are most likely caused by the accumulation of a defective protein in which of the following locations in muscle cells? A) Cytoplasm B) Lysosome C) Mitochondria D) Nuclear membrane E) Peroxisome F) Smooth endoplasmic reticulum h