About Alpha-Mannosidosis

Alpha-Mannosidosis is a rare Lysosomal Storage Disease (LSD) caused by mutations affecting the alpha-mannosidase lysosomal enzyme. This enzyme is an exoglycosidase, that cleaves α-linked mannose residues of N-linked oligosaccharides. If the alpha-mannosidase enzyme is impaired, degradation of glycoproteins is blocked and a progressive accumulation of mannose-rich oligosaccharides occurs in all tissues, leading to impaired cellular function and apoptosis.1

about-alphamannosidosis

This impaired cellular function has a downstream impact upon organ systems, with typical presentation reflected as skeletal deformation, coarse facial features, hearing loss, cognitive disabilities, immune defects, and central nervous system involvement.1

The prevalence of Alpha-Mannosidosis is not known exactly. However, a number of reports from different countries estimate that it occurs in approximately one in every million babies born worldwide.2 The condition is often diagnosed and treated using a multi-disciplinary approach, involving paediatricians, orthopedics, ophthalmologists, otologists neurologists, immunologists, neurosurgeons and physiotherapists.3

Alpha-Mannosidosis is a progressive disorder, and its presence should be suspected in patients with mental cognitive disabilities, skeletal changes (eg swollen joints, curved spine), hearing loss and recurrent infections. Although children with the condition are often born seemingly normal, their condition deteriorates with age.
Alpha-Mannosidosis can impact on a patient’s quality of life in many ways, including their ability to live independently, socialise or find employment.3,4

Mechanism of the disease

Learn about disease mechanisms
mechanism-of-disease
Understanding Alpha-Mannosidosis begins here

Understanding
Alpha-Mannosidosis begins here

  1. Borgwardt, L. et al. Alpha-mannosidosis: correlation between phenotype, genotype and mutant MAN2B1 subcellular localisation. Orphanet J Rare Dis 10, 70 (2015).
  2. Beck, M. et al. Natural history of alpha mannosidosis a longitudinal study. Orphanet J Rare Dis 8, 88 (2013).
  3. Borgwardt, L., Lund, A. M. & Dali, C. I. Alpha-mannosidosis – a review of genetic, clinical findings and options of treatment. Pediatr Endocrinol Rev 12 Suppl 1, 185–191 (2014).
  4. Malm, D. & Nilssen, Ø. Alpha-mannosidosis. Orphanet Journal of Rare Diseases 3, 21 (2008).