Disease progression

Alpha-Mannosidosis is a lifelong multi-systemic progression with neuromuscular and skeletal deterioration over decades. The timing of the appearance of symptoms correlates with the severity of the disease. Neonates with lysosomal disorders are mostly asymptomatic and only rarely severely affected, which delays diagnosis.^{1 ,2}

The first decade of life is characterised by early development of hearing impairment, psychomotor delay, frequent recurrent infections, especially upper airway infections, pulmonary infections and acute/serous otitis media infections.³

During the second and third decades of their lives, patients develop polyarthropathy, ataxia, muscle weakness, and severe skeletal problems, which eventually leave the patient unable to walk. Patients typically present with skeletal and facial abnormalities, hearing loss, intellectual disability, and immune deficiency.¹

In the more severe form, where the condition appears in infancy in most cases, and leads to early death following severe infections.¹ However, those presenting with the milder form can usually survive into adulthood.¹

When a neonate or infant has hearing difficulties and impaired motor skills, recurrent infections or skeletal abnormalities that child should be tested for lysosomal storage disease and Alpha-Mannosidosis. Urine tests and blood tests for enzyme activity are reliable in establishing a diagnosis.¹ Genetic testing can detect the mutation of the MAN2B1 gene that causes Alpha-Mannosidosis, thus facilitating early identification and treatment.¹