Myoclonus, Cerebellar Ataxia, And Deafness

Clinical Features

May and White (1968) described a new syndrome of familial myoclonus, cerebellar ataxia and deafness and concluded that it is autosomal dominant. Evidence is meager; however, a mother and son had the full syndrome. Hearing loss was noted in childhood or early adulthood. Myoclonic jerks and cerebellar symptoms began at age 14 in the son. Chayasirisobhon and Walters (1984) observed the syndrome in identical twins. In both, bilateral hearing loss was detected at age 8 years and myoclonic jerks began at age 13. Unsteadiness of gait began in the mid-teens. Light and bright colors provoked intermittent jerky movements and EEG changes. Generalized tonic-clonic seizures also occurred but were controlled with phenytoin and valproic acid. See deafness, congenital, and familial myoclonus epilepsy (220300).