Congenital (persistent) myasthenia gravis is rarely diagnosed in the newborn period, but it may cause respiratory distress and even death. Most patients have a mild degree of weakness, often limited to the extraocular muscles, and their conditions are diagnosed at a later age.
Three siblings, two of whom were identical twins, had severe respiratory symptoms. With crying they developed grunting respirations and weak cry, followed by pallor, cyanosis, generalized weakness, apnea, and unconsciousness. The twins responded to intramuscularly administered neostigmine bromide within a few minutes. The oldest child, a boy, died during an episode at 6 months of age. One twin died in a similar manner at 21 months. Postmortem examinations revealed no significant findings.
Twin studies and familial incidence suggest an autosomal recessive heredity.
William T. McLean, Robert C. McKone. Congenital Myasthenia Gravis in TwinsIdentical Twins With Crises in the Newborn Period. Arch Neurol. 1973;29(4):223–226. doi:10.1001/archneur.1973.00490280035004