BETA-MANNOSIDASE DEFICIENCY - HETEROGENEOUS MANIFESTATION IN THE 1ST FEMALE-PATIENT AND HER BROTHER

β-Mannosidase deficiency was demonstrated in fibroblasts of a girl who showed severe psychomotor retardation, bone deformities and gargoylism and recurrent skin and respiratory infections and who died at 20 years of age from bronchopneumonia. This first demonstration of a female patient confirms the autosomal recessive inheritance of β-mannosidosis. Further investigation of this gipsy family revealed β-mannosidosis in an older brother with a milder manifestation of gargoyl facial dysmorphology, mental retardation, hearing impairment and recurrent infections. β-Mannosidase activity was completely deficient in his cultured skin fibroblasts, leukocytes and plasma. In urine a characteristic disaccharide was present. Heterozygote levels of β-mannosidase were found in fibroblasts and/or plasma of the parents and one sister. © 1990 SSIEM and Kluwer Academic Publishers.