CONGENITAL MYASTHENIA IN SIBLINGS

Abstract

THERE is a group of neuromotor disorders of early life in which the disease process becomes evident clinically before birth. The prenatal manifestations of the disorder are a delay of quickening and a reduction in the amount of fetal activity. This symptom of impaired fetal movement has been previously reported in a number of cases of amyotonia congenita (Oppenheim), apparently having first been noted by Foot1in 1913. Fetal inactivity does not refer to a specific clinicopathologic disease process, but merely indicates prenatal suppression of neuromuscular mechanisms controlling motor behavior. Thus, in the following cases a myasthenic syndrome was present from birth, and one may surmise from the prenatal history that muscular function (or neuromuscular transmission) of the fetus was similarly defective. REPORT OF CASES Case 1. —In the case of J. E. B., a male infant, quickening began during the seventh month of the mother's pregnancy and was