Lethal arthrogryposis multiplex congenita: a pathological study of 21 cases.

Twenty-one cases of arthrogryposis multiplex congenita, which had resulted in death soon after birth or had been aborted following prenatal diagnosis, were studied. Histochemical and histological study of muscle indicated that 11 cases were of myogenic origin, including congenital muscular dystrophy in 10 cases from six families and nemaline rod myopathy in one. Neurogenic causation was established in five cases, including three with intra-uterine anoxic-ischaemic damage and two siblings with a severe form of cerebro-ocular-facio-skeletal syndrome. Causation remained uncertain in five. Unusual features included atrophy or amyoplasia of the diaphragm associated with lung hypoplasia in 10 cases and evidence of birth trauma in seven cases. One pair of siblings had subcutaneous tissue of doughy consistency and another pair had bladder hypertrophy. Familial recurrence was seen most often in cases with evidence of myogenic origin. We consider that neuropathology and muscle histochemistry are essential aids in determining the risks of recurrence in this group of lethal conditions which defy analysis by syndrome recognition techniques.