The attenuated/late onset lysosomal storage disorders: Therapeutic goals and indications for enzyme replacement treatment in Gaucher and Fabry disease.

Enzyme replacement therapies have been developed and authorized for commercial use for six different lysosomal storage disorders. For Gaucher disease, Fabry disease and mucopolysaccharidosis type 1, disease-specific treatments have been available for more than a decade. Although long term follow-up data are still sparse, therapeutic goals for patients with Gaucher disease and Fabry disease have been formulated and published for both adults and children. Without adaptation or modification, these goals are often applied in clinical research and in routine patient care across the entire phenotypic spectrum of disease, although in practice, patients commonly manifest high variability in clinical presentation and course of the illness. In this context, establishing goals for the follow-up and treatment of late onset/attenuated phenotypes is particularly challenging. In this chapter, we review current therapeutic goals for Gaucher disease and Fabry disease and discuss approaches for those with attenuated disease manifestations.