The Koala

Alpha-Mannosidosis

Alpha-mannosidosis, a glycoproteinosis, is due to a genetic defect of the lysosomal enzyme alpha-mannosidase that is responsible for the hydrolysis of glycoprotein carbohydrate moieties. The decreased activity of this enzyme leads to accumulation of oligosaccharides in several cells and organs. Alpha-mannosidosis is a slowly progressive disorder that shows a broad phenotypic variability. Clinical features include hearing impairment, skeletal abnormalities, impairment of mental function, sometimes periods of psychosis. In addition, muscular weakness and ataxia are observed. In the first decade of life recurrent infections occur due to an immune defect.