ABSTRACT
The infantile or classic form of mannosidosis is characterized by a very early onset of a disease that resembles a severe mucopolysaccharidosis. Hematologic evaluation regularly reveals vacuolated lymphocytes in patients with all types of mannosidosis. Polymorphonuclear leukocytes may also be vacuolated, and the bone marrow may reveal foamy macrophages. α-Mannosidosis is an autosomal recessive disease, and affected offspring have been of both sexes. The defective enzyme, acid α-mannosidase, is lysosomal and is synthesized in a precursor form followed by processing into smaller subunits assembled in human liver into forms which are separable by chromatography and electrophoresis but immunologically indistinguishable. Bone marrow transplantation has been reported to stabilize intellectual function and improve hearing. Another disorder of glycoprotein catabolism, β-mannosidosis, was first described in goats, which displayed a severe degree of neurodegeneration. It is now apparent that this disease also occurs in man.
