Beta-mannosidosis

The β - mannosidosis is an extremely rare autosomal recessive lysosomal storage disease belonging to the group of oligosaccharidoses.

Prevalence

The β - mannosidosis is a prevalence of less than 1: 1,000,000 in live-born children a very rare disease. Worldwide by 2008, only 20 cases have been reported in 16 families. Due to the poor data situation, the symptoms are not described adequately secured.

Symptoms

Similar to the α - β - mannosidosis the mannosidosis in affected patients by immune deficiency, mental retardation, delayed speech development, changes in the skeleton and hearing loss is identified. In addition, in some cases, hypotension and seizures. The weakened immune system has recurrent respiratory infections result.

Genetics and pathogenesis

The β - mannosidosis is based on an autosomal recessive mode of inheritance. Mutations in Manba gene locus is located on chromosome 4 q22 - q25, are the cause of the disease. Manba the gene encodes β -mannosidase for the enzyme. Mutations in this gene can result in a decreased activity of β -mannosidase, which accumulate disaccharides of mannose in the tissues of affected patients.

Diagnosis

The diagnosis can be made by determining the activity of β -mannosidase in leukocytes or cultured fibroblasts. A DNA analysis ( genetic testing ) may be performed to confirm the results. Excretion of increased amounts of mannose disaccharide in the urine is an indication of the disease, but no specific detection. Prenatal diagnosis is both biochemical and molecular genetic methods possible.

Therapy

No specific therapy is not yet known. The disease is treated symptomatically.

First description and Veterinary Medicine

The disease was first described in 1981 in goats, and five years later the first time in humans. The disease in goats is much more serious and leads to an early death of the animals. In cattle, the disease was first detected in 1993.