Alpha-mannosidosis

Alpha-mannosidosis is a genetic condition that causes a progressive storage disorder in the body's organs. Genetic changes or mutations in the MAN2B1 gene cause complex sugar molecules, called oligosaccharides, to build up in different parts of the body. This buildup of oligosaccharides causes health problems for people with alpha-mannosidosis, which is why it is called a storage disorder or, more specifically, a lysosomal storage disorder. The main health problems that result from the buildup of oligosaccharides in people with alpha-mannosidosis include intellectual disability, pronounced or "coarse" facial features, and skeletal issues like abnormally shaped back bones (vertebrae), thickened bones at the top of the skull, reduced bone density (osteopenia), bowed legs, and knock-knee abnormalities. People with alpha-mannosidosis can also have medical problems such as frequent infections, hearing loss, vision loss from cloudy corneas, enlargement of the liver and spleen, muscle weakness, and difficulties coordinating movement (ataxia).