Lysosomal Storage Disorders

What are Lysosomal Storage Disorders? Lysosomal storage disorders are inherited disorders caused by inborn errors of lysosomal metabolism that are characterized by an absence or deficiency of an enzyme. The lack of sufficient enzyme leads to the accumulation of the substrate within the cells. Each lysosomal storage disease has characteristic symptoms that affect different parts of the body depending upon the enzyme that is deficient.

There are over 50 known lysosomal storage disorders, and while they are individually considered rare diseases, collectively they are diagnosed in 1 in 5000 live births. Some lysosomal storage diseases occur more commonly in certain populations as seen in the increased prevalence of Gaucher and Tay Sachs disease in the Ashkenazi Jew population. 

Classification of Lysosomal Storage Disorders

Lysosomal storage diseases are often classified in broad categories based upon the substrates accumulated:

  • Sphingolipidosis (phospholipids containing complex sphingosine): GM2 gangliosidosis, Niemann-Pick disease, Gaucher disease, Fabry disease.
  • Oligosaccharidosis (glycoproteins): Schindler disease, Aspartylglucosaminuria.
  • Mucopolysaccharidosis (glycosaminoglycans): Hurler syndrome, Scheie syndrome, Hunter syndrome.
  • Neuronal ceroid lipofuscinosis (lipofuscin): CLN 1-14
  • Sialic acid disorder (sialic acid): Galactosialidosis, Infantile sialic acid storage disease, Sialuria.
  • Mucolipidosis (mucolipids): Mucolipidosis I-IV, including Sialidosis, I-cell disease, Pseudo-Hurler-polydystrophy.
  • Glycogen storage disease (glycogen): Pompe disease, Danon disease

Source: NORD – National Organization for Rare Disorders. (2017, August 28). Lysosomal Storage Disorders. Retrieved May 30, 2022, from https://rarediseases.org/rare-diseases/lysosomal-storage-disorders/