Benign congenital myopathy with myasthenic features.

It has been increasingly apparent in recent years that in addition to cases which fall into recognizable categories of muscle disease, a number of less common disorders occur from time to time which do not correspond to the accepted descriptions. Some of these appear to be metabolic in origin and can be elucidated, at least in part, by modern methods of investigation (McArdle, 1951) while others seem to fall into a borderland of either myopathy or myasthenia gravis. A case of the latter type is described and discussed below.