Duchenne muscular dystrophy: plasma membrane loss initiates muscle cell necrosis unless it is repaired.

Study of biopsies from 30 boys with Duchenne muscular dystrophy suggests that necrosis of muscle cells is initiated by loss of plasma membrane, followed, after a short interval, by Z disc lysis and mitochondrial changes to constitute the picture of fully developed necrosis. Empty basal lamina tubes containing collagen indicated that regeneration may fail to occur. The tubes form a basis for collagen deposition. Evidence suggests that small patches of membrane loss can be repaired, though a slice of superficial cytoplasm is lost, and a piece of detached basal lamina results. The markedly hypercontracted fibres seen did not show features of necrosis.