BACKGROUND There are 45 known genetic diseases that impair the lysosomal degradation of macromolecules. The loss of a single lysosomal hydrolase leads to the accumulation of its undegraded substrates in tissues and increases of related glycoconjugates in urine, some of which can be detected by screening of free oligosaccharides (FOS) in urine. Traditional 1-dimensional TLC for urine oligosaccha...

Lysosomal storage diseases comprise a group of about 40 disorders, which in most cases are due to the deficiency of a lysosomal enzyme. Since lysosomal enzymes are involved in the degradation of various compounds, the diseases can be further subdivided according to which pathway is affected. Thus, enzyme deficiencies in the degradation pathway of glycosaminoglycans cause mucopolysaccharidosis, ...

Enzyme replacement therapy (ERT) has been approved for 6 lysosomal storage diseases (LSDs) worldwide including Japan. These diseases include Gaucher disease (GD), Fabry disease, mucopolysaccharidosis (MPS) types I, II, and VI, and Pompe disease (PD). The efficacy and safety of ERT for LSDs has been confirmed by extensive clinical trials. However, there are still obstacles to successful ERT, suc...

Lysosomes are organella involving the catabolism of biomolecules extracellularly and intra‐ cellularly incorporated, which contain more than 60 distinct acidic hydrolases (lysosomal enzymes) and their co-factors. Lysosomal storage diseases (LSDs) are caused by germ-line gene mutations encoding lysosomal enzymes, their activator proteins, integral membrane proteins, cholesterol transporters and ...