Missense and Nonsense Mutations in the Lysosomal α-Mannosidase Gene (MANB) in Severe and Mild Forms of α-Mannosidosis

alpha-Mannosidosis is an autosomal recessive lysosomal-storage disorder caused by a deficiency of lysosomal alpha-mannosidase activity. This disease shows a wide range of clinical phenotypes, from a severe, infantile form (type I), which is fatal at