All about the symptoms of Alpha Mannosidosis?

Due to the heterogeneity of the disease, the symptoms of Alpha Mannosidosis may initially be confused with those of other medical conditions.1 Diagnoses are made by doing a urine analysis2, using blood tests to measure enzyme activity in white blood cells and genetic analyses.3

It’s important to talk to your doctor about all the symptoms you notice in your child, as your doctor may not think about the possibility of Alpha Mannosidosis. Often, symptoms start with a child feeling weak, getting ear infections, and having issues with developing language skills.4,5

The symptoms of Alpha Mannosidosis, like other related conditions, are extremely varied. Some people will have mild to moderate learning difficulties that develop in childhood or adolescence6, while others may have more severe symptoms that develop from a very early age.7,8

The wide range of possible symptoms are presented in the diagram below, however affected individuals may not experience all of them.

Signs of Alpha Mannosidosis9A

Alpha Mannosidosis symptoms

Persons may have fluid build-up in the brain

Hearing loss
Almost all individuals suffering from alpha mannosidosis will have some degree of hearing loss

Skeletal abnormalities in many individuals include scoliosis, or curvature of the spine

Immunodeficiency and autoimmunity recurrent infection, especially in the first decade of life

Mental functions individuals with alpha mannosidosis usually have some signs of learning disability, which can be mild or more severe. Such signs include difficulty in learning to speak

Facial features tend to be coarse

Persons may have polyarthropathy, a disease involving multiple joints

Motor control
Persons with alpha mannosidosis may often appear to be clumsy, which is cause by muscleweakness and abnormalities in their joints

  1. Alpha Mannosidosis. DoveMed 2017.
  2. Malm D & Nilssen ø. Alpha-mannosidosis. Orphanet J Rare Dis 2008;3:21
  3. Malm D & Nilssen ø. Alpha-mannosidosis. Orphanet J Rare Dis 2008;3:21
  4. Alpha-Mannosidosis. MPS Society ( – Last accessed March 2024)
  5. Alpha Mannosidosis. National Organization for Rare Diseases (NORD) Factsheet 2015.
  6. Alpha-Mannosidosis. MPS Society ( – Last accessed March 2024)
  7. Malm D & Nilssen ø. Alpha-mannosidosis. Orphanet J Rare Dis 2008;3:21
  8. Beck M, Olsen KJ, Wraith JE et al. Natural history of alpha-mannosidosis: a longitudinal study. Orphanet J Rare Dis 2013;8:88
  9. Malm D, Nilssen O. Alpha-Mannosidosis. NCBI. Available at:

The information on this website is intended only to provide knowledge of Alpha Mannosidosis disease health topics. This information should not be used in place of advice from your GP or other healthcare professional. If in doubt please contact your doctor for advice. This website has been produced by Chiesi Pharmaceuticals. The website has been developed in accordance with industry and legal standards to provide information for healthcare professionals and the general public about Alpha Mannosidosis disease health topics. Chiesi Pharmaceuticals makes every reasonable effort to include accurate and current information. However, the information provided in this website is not exhaustive.