Tuesday 29 July 2008
Alpha-mannosidosis is an autosomal recessive lysosomal storage disease of glycoprotein catabolism caused by a deficiency of lysosomal alpha-mannosidase activity. The disorder shows a wide range of clinical phenotypes, from a severe infantile form (type I), which is fatal at less than 3 to 8 years of age, to a less severe juvenile- or adult-onset form (type II), which ultimately shows progressive neurologic degeneration.
Beta-mannosidosis is an autosomal recessive lysosomal storage disease of glycoprotein catabolism caused by a deficiency of lysosomal beta-mannosidase activity. Most patients have mental retardation.
alpha-mannosidosis (MIM.248500): mutation in the gene encoding alpha-mannosidase, class 2B1 (MAN2B1) (MIM.609458)
beta-mannosidosis : mutation in the gene encoding beta-mannosidase (MANBA) (MIM.609489).