Diagnostic algorithm

Alpha-Mannosidosis is a rare disease, and its timely diagnosis has the potential to influence patient outcomes since management and preventive therapies can be initiated at an early stage. Currently, early diagnosis is mainly hampered by:1

  • the rarity of the disease;
  • the variety of signs/symptoms observed;
  • the wide range of disease severity.

A standardised diagnostic algorithm might help to overcome this gap.1

In 2019, with no internationally recognized guidelines for early diagnosis of Alpha-Mannosidosis, an international working group of experts met to establish an algorithm to help general practitioners and specialists (metabolic and non-metabolic) achieve early diagnosis and initiate adequate treatment as soon as possible.1

Two consensus proposals were developed for diagnostic algorithms of Alpha-Mannosidosis:

Patients ≤10 years of age in which hearing impairment and/or speech delay are the cardinal symptoms that should prompt the clinician to look for additional symptoms that may provide further diagnostic clues.1

 

patients

Algorithm
in patients ≤10 years

In patients ≤10 years of age, the presence of hearing impairment and/or speech delay is the main motivator to look for Alpha-Mannosidosis. The presence of hearing impairment or speech delay should then lead the clinician to look for evidence of additional symptoms. If these additional symptoms are not identified, then additional monitoring can be carried out or patients can be referred to a metabolic center for additional testing at the discretion of the physician.1

algorithm patients less 10
Modified from fig 1 ref 1: Proposed algorithm for diagnosis of alpha-mannosidosis in patients ≤10 years. (Abbreviations: MPS, mucopolysaccharidosis)1

Patients >10 years of age have different clinical presentations, and the presence of mental retardation and motor impairment progression and/or psychiatric manifestations should prompt the clinician to assess for other symptoms.1

Patient > 10 years

Algorithm
in patients >10 years of age

For patients >10 years of age, the presence of mental retardation and motor impairment progression and/or psychiatric manifestations (including acute psychotic events) should prompt assessment of clinical history for two of the following symptoms:1

  • hearing impairment;
  • intellectual disability;
  • motor disturbances/ataxia;
  • skeletal disorders/joint diseases.

If these conditions are not met then additional monitoring can be carried out, or patients can be referred to a metabolic center for additional testing.1

algorithm patients over 10
Modified from fig 2 ref 1: Proposed algorithm for diagnosis of alpha-mannosidosis in patients >10 years. (* Includes acute psychotic events).1
Diagnostic algorithm for Alpha-Mannosidosis

Diagnostic algorithm
for Alpha-Mannosidosis

Learn about the clinical characteristics of Alpha-Mannosidosis
Learn about the symptoms and red flags

  1. Guffon, N. et al. Recognition of alpha-mannosidosis in paediatric and adult patients: Presentation of a diagnostic algorithm from an international working group. Molecular Genetics and Metabolism 126, 470–474 (2019).