Conceptual

Lysosomal Storage Diseases: Enzyme Deficiencies and Clinical Findings for USMLE Step 1

Lysosomal storage diseases represent a class of inherited metabolic disorders defined by specific enzymatic deficiencies within lysosomes, resulting in the pathological accumulation of undegraded substrates and subsequent cellular dysfunction across various organ systems including bone marrow, liver, spleen, brain, kidneys, eyes, heart, skin, nerves, and joints. The domain encompasses glycogen storage diseases (excluding Pompe), sphingolipidoses like Fabry, Gaucher, Tay-Sachs, Niemann-Pick, Krabbe/CRD/GM1, mucopolysaccharidosis II, Hurler's syndrome, metachromatic leukodystrophy and I-cell disease. These conditions relate to the parent discipline of biochemistry and molecular genetics as fundamental models for studying intracellular trafficking mechanisms, lysosomal degradation pathways, and structure-function relationships between specific enzymes and their cognate substrates.