Mannosidosis
Mannosidosis– accumulation disease, which develops as a result of insufficiency of lysosomal mannosidases. Two etiologically and clinically different forms have been identified. a Mannosidosis develops with deficiency of α-mannosidase (*248500, EC 3.2.1.24, 19pl3.2-ql2, MANBA gene, p). Depending on the severity of symptoms and periods of onset, 2 forms of the disease are distinguished: a more severe type 1 (children’s) and a mild youthful form – type II. Clinical manifestations: vomiting, splenomegaly, coarse features of a broad face, macroglossia, wide spaces between teeth, deafness, clouding of the lens, muscle weakness, features of multiple dysostosis, repeated respiratory infections, mental retardation, dilated cerebral ventricles. Laboratory: mannosuria,. vacuolization of lymphocytes, pancytopenia, AT to platelets and neutrophils, low content of haptoglobins, hypogammaglobulinemia. Differential diagnosis: sialidosis, Hürler’s syndrome. Attempts to treat zinc were unsuccessful, but bone marrow transplantation had some effect. p Mannosidosis — deficiency of p-mannosidase (*248510, mannase, EC 3.2.1.25, MANBB gene, Xp. 4?, p). Characterized by deafness, mental retardation, behavioral abnormalities, moderate deformations of the bone skeleton, angiokeratomas. Laboratory: in the urine disaccharides, mannosyl(1-4)-M-acetylglucose, heparan sulfate. Differential diagnosis: Sanfshisho’s syndrome, fucosidosis, sialidosis, aspartyl glycosaminuria. ICD-10. E77.1 Defects in glycoprotein degradation Literature. Bennet JK et al: Clinical and biochemical analysis of two families with type I and type II mannosidosis. Am. J. Med. Genet. 55:21-26, 1995; Leipprandt JR et al: Caprine p-mannosidase: sequencing and characterization of the cDNA and identification of the molecular defect of caprine p-mannosidosis. Genomics 37:51-56, 1996; Nilssen 0 et al: a-Mannosidosis: functional cloning of the lysosomal a-mannosidase cDNA and identification of a mutation in two affected siblings. Hum. Molec. Genet. 6: 717-726, 1997; Riise HMF et al: Genomic structure of the human lysosomal a-mannosidase gene (MANB). Genomics 42: 200-207, 1997; Rodriguez-Serna M et al: Angiokeratoma corporis diffusum associated with p-mannosidase deficiency. Arch. Derm. 132: 1219-1222, 1996 Genet. 6: 717-726, 1997; Riise HMF et al: Genomic structure of the human lysosomal a-mannosidase gene (MANB). Genomics 42: 200-207, 1997; Rodriguez-Serna M et al: Angiokeratoma corporis diffusum associated with p-mannosidase deficiency. Arch. Derm. 132: 1219-1222, 1996 Genet. 6: 717-726, 1997; Riise HMF et al: Genomic structure of the human lysosomal a-mannosidase gene (MANB). Genomics 42: 200-207, 1997; Rodriguez-Serna M et al: Angiokeratoma corporis diffusum associated with p-mannosidase deficiency. Arch. Derm. 132: 1219-1222, 1996