IllnessMannosidase deficiency

NGS +

Mannosidase deficiency can be divided into α- and β-mannosidosis. α-mannosidosis affects many organs and tissues. Affected individuals may have mental retardation, prominent facial features and skeletal abnormalities. The latter include osteopenia, thickened skull bones, deformities of the vertebrae, knock knees as well as bone and joint affections. These patients may also have ataxia, myopathy, psychomotor retardation, increased risk of infection, hepatosplenomegaly, hydrocephalus, hearing loss and cataract. Psychiatric symptoms occur also in several α-mannosidosis patients. The symptoms can range from mild to severe. The disease can occur in infancy, progress rapidly and lead to severe neurological deterioration. Affected individuals with this early-onset form often do not survive childhood. In the most severe cases, a fetus may even die before birth. Other patients suffer milder symptoms that occur later and progress more slowly. People with later-onset α-mannosidosis can survive until they are fifty years old. The mildest cases can only be detected by laboratory tests and cause few, if any, symptoms. Mutations in the MAN2B1 gene cause α-mannosidosis.

The symptoms of β-mannosidosis vary widely, and the disorder nay begins between infancy and adolescence. Almost all patients with β-mannosidosis have mental retardation, some show delayed motor development and seizures. The affecteds may be extremely introverted, prone to depression or have behavioral problems. β-mannosidosis patients have an increased risk of respiratory and ear infections, hearing loss, speech disorders, difficulty swallowing, muscle hypotonia and peripheral neuropathy. They may also have prominent facial features and numerous angiokeratomas. Mutations in the MANBA gene cause β-mannosidosis. Both forms of mannosidase deficiency, α- and β-mannosidosis, are inherited in an autosomal recessive manner. The diagnostic yield is not precisely known. Therefore, clinical biochemical diagnosis cannot be refuted on the basis of a negative DNA test result.

Reference: https://www.ncbi.nlm.nih.gov/books/NBK1396/

https://medlineplus.gov/genetics/condition/beta-mannosidosis/

• Alais: Lysosomal alpha-D-mannosidase deficiency
• Alias: Alpha-D-mannosidosis
• Alias: Alpha-mannosidase B deficiency
• Alias: Alpha-mannosidase deficiency
• Alias: Beta-D-mannosidosis
• Alias: Beta-mannosidase deficiency
• Alias: Beta-mannosidosis
• Alias: Deficiency of alpha-mannosidase
• Alias: Lysosomal alpha B mannosidosis
• Alias: Lysosomal alpha-D-mannosidase deficiency
• Alias: Lysosomal beta A mannosidosis
• Alias: Lysosomal beta-mannosidase deficiency
• Alpha-Mannosidose (MAN2B1)
• Mannosidosis, alpha-, types I + II (MAN2B1)
• Mannosidosis, beta (MANBA)