Inborn Errors of Metabolism Involving Complex Molecules: Lysosomal and Peroxisomal Storage Diseases

Peroxisomes and lysosomes are distinct subcellular compartments that underlie several pediatric metabolic disorders. Knowledge of their function and cell biology leads to understanding how the disorders result from genetic defects. Diagnostic and therapeutic approaches for the disorders take advantage of the cell biology mechanisms. Whereas peroxisomal disorders are characterized by enzymatic defects in peroxisomal pathways leading to metabolic and lipid changes, lysosomal storage disorders are marked by accumulation of substrates of lysosomal pathways inside the lysosome. The human diseases related to these two organelles are reviewed, focusing on general disease patterns and underlying diagnosis and treatment principles.