Infantile centronuclear myopathy Evidence suggesting incomplete innervation

A male case of centronuclear myopathy is reported, with severe weakness at birth and death at 7 weeks. In all the muscles studied the fibres, despite their immature appearances, showed normal histochemical differentiation into type I and type II moieties. In contrast to the extrafusal fibres, the intrafusal fibres seemed to be normal in their development. Although the small centrally-nucleated muscle fibres were equipped with motor end-plates, …