α-Mannosidosis is an inherited lysosomal storage disorder caused by genetic mutations leading to limited or no expression of a gene responsible for metabolizing oligosaccharides.
Besides the low awareness for α-mannosidosis, clinical assessment based on phenotypic data and clinical symptoms is challenging, especially in contrast to mucopolysaccharidosis (MPS). In a pilot study, we investigated the addition of α-mannosidase enzyme activity analysis in individuals suspicious of MPS.
Although α-Mannosidosis is considered to be ultra-rare, studies indicate it may be underdiagnosed.
We analyzed α-mannosidase activity in over 1,000 residual DBS samples previously tested for six different MPS types. Our study identified four α-mannosidosis positive patients who were originally suspected of an MPS. These results underline the necessity for diagnostic initiatives as well as a general discussion in the community of lysosomal storage diseases. The study and our results can be read in Molecular Genetics and Metabolism.
Our Medical Laboratory offers differential tests and diagnostic panels for Lysosomal Storage Disorders including α-mannosidosis and mucopolysaccharidoses. Genetic confirmatory testing is available usually on the same DBS sample.