STUDIES IN DISORDERS OF MUSCLE. VII. CLINICAL MANIFESTATIONS AND INHERITANCE OF A TYPE OF PERIODIC PARALYSIS WITHOUT HYPOPOTASSEMIA 1

Abstract

A study of periodic paralysis occurring in 33 individuals in 7 generations of a single kindred is reported. Clinically the'' disorder begins in infancy with recurrent attacks of weakness of flaccid paralysis. Some extensor weakness and enlargement of muscles is evident at all times. The attacks are most consistently produced by vigorous exercise followed by complete rest. No correlation of the attacks with the serum K or other electrolyte concns. could be established. An unusual pathologic picture of vacuolization of scattered muscle fibers was found in biopsy material. Neither fat nor glycogeh could be demonstrated in the vacuoles and it is presumed that they contained only edema fluid. The pattern of inheritance is that characteristic of a simple Mendelian dominant trait with complete penetrance.