Thelansis

  Alpha-mannosidosis is an autosomal recessive lysosomal storage disease caused by MAN2B1 gene mutations. It is diagnosed by detecting low levels of acidic alpha-mannosidase enzyme activity in peripheral blood leukocytes or cultured skin fibroblasts, with affected individuals displaying 5–15% of regular leukocyte activity. In most patients, the disease is clinically recognised in the first decade of life, progression is slow, and ataxia develops between 20 to 30 years. Long-term enzyme replacement therapy (ERT) is a treatment option for alpha-mannosidosis, and the first human recombinant form of alpha-mannosidase available for ERT is velmanase alfa. Patients with alpha-mannosidosis who were treated with velmanase alfa improved in biomarkers, motor function, pulmonary function, immunologic profile, and quality of life in clinical trials. Intracellular accumulation of mannose-rich oligosaccharides causes various clinical symptoms, including hearing loss, intellectual disabilities, an...