SUMMARY The clinical and histological features of two Negro brothers with a centronuclear myopathy are described. They bring to 19 the number of cases now reported with this constellation of physical signs and pathological changes in the muscles. A review of these patients suggests the existence of several different diseases causing this picture, though presumably the underlying biochemical defects are closely related. It is concluded that these myopathies are degenerative rather than due to arrest of foetal muscle maturation. Spiro, Shy, and Gonatas (1966) described a boy with a congenital myopathy affecting all skeletal muscles, and especially causing external ophthalmoplegia, ptosis, and facial weakness. Up to 85% of the skeletal muscle fibres had central nuclei. The authors suggested that these fibres represented foetal myotubes persisting into adolescence, and named the condition 'myotubular myopathy'. Since then, 16 further cases believed to be suffering from the same condition have been reported (see Table 1). The theory of the persistence of myotubes has not won universal acceptance, and the term 'centronuclear myopathy' is to be preferred.We have studied a further pair of brothers with this condition, and record our findings in this report. A review of the 19 total cases shows a lack of uniformity in the age of onset, clinical features, and histochemical characteristics. The question of whether more than one disease entity is included will be discussed. facial, palatal, and lingual movements. The temporalis muscles were atrophic, but the masseter, stemomastoid, and upper trapezius muscles were of normal bulk. Movements of the extremities were extremely weak, especially proximally, and the limb girdle muscles particularly atrophic. The respiratory muscles were weak, with a thoracic kyphoscoliosis. A cardiac ejection systolic murmur was heard. The ECG showed right ventricular hypertrophy.The muscle weakness worsened, and at 34 years of age he was readmitted to the hospital because of dyspnoea. He was still able to feed himself and roll over in bed, but could do little else. A few days after admission he died of aspiration.Post-mortem examination disclosed bronchopneumonia, focal fibrosis of the myocardium, and a small colloid goitre. The skeletal muscles were pale and atrophic; the histological findings are described below. Numerous levels of the spinal cord showed no abnormality; the complement of motor neurones was normal. The smooth muscle of the gut, bladder, and blood vessels was normal. At necropsy the skeletal muscles were pale and atrophic. Sections from two (unstated) muscles showed changes similar to those in his brother's muscles (see below). The complement of motor neurones in the spinal cord was normal. The brain showed only anoxic changes. The smooth muscle of gut, bladder, and blood vessels, and the myocardium were normal.
FAMILY HISTORYThe parents of the two brothers (cases 1 and 2) were not known to have primary muscular disease, and there was no consanguinity in the family. The father, a...
