The clinical course of mannosidosis.

The clinical course of mannosidosis was studied in eight patients. The age at onset of symptoms varied from 6 months to 3 years. The first symptom was usually delayed development of speech or motor or mental functions and was often accompanied by recurrent infections. All the patients were mentally retarded, with slightly coarse facial features, poor ability to speak, sensorineural hearing loss and dysostosis multiplex. Ataxia was seen in all but one case, appearing in childhood at the same time as the hearing loss. Follow-up observations suggested gradual impairment of mental and motor functions and speech with age. Other findings were stunted growth in adults, and vacuolated lymphocytes in the peripheral blood.