The Richards-Rundle syndrome (RRS) is characterized by hearing loss, mental deterioration, ataxia, primary hypogonadism and autosomal recessive transmission. In a sibship of six members we found two sisters with RRS together with baldness, impaired GH and PRL secretion after stimulation and different degrees of impaired insulin secretion. Cochleovestibular investigation of the sibship revealed in each subject more or less severe forms of bulbo-pontine cochleovestibular dysfunction. Three members of the same sibship had cutaneous signs of abortive forms of neurofibromatosis: the son of one of these subjects had a severe form of fully developed neurofibromatosis. Whether there is a pathogenetic linkage between the hereditary multisystemic degeneration (RRS), the dysembryopathy (neurofibromatosis) and the cochleovestibular dysfunction in this family is still not clear.