Lysosomal glycoprotein storage disease with mental
retardation, hearing loss, and recurrent infections (upper or lower
respiratory tract, and gastrointestinal tract). Other clinical features include
coarse face, prominent forehead, prominent jaw, diffuse dysfunction of the
brain, severe ataxia, deafness, scoliosis, rheumatoid arthritis, hypotonia,
and muscle pain. Two types are described: α and β. α-Mannosidosis displays clinical heterogeneity, ranging from very serious to
very mild forms. β-Mannosidosis causes a severe disorder that affects
the peripheral and central nervous systems.