Learn / FMK
Every FMK condition
299 diseases, deficiencies, toxicities and drug mechanisms harvested from every FMK deck — the ones sprinkled through a single bullet as much as the ones with their own slide. Pick what you're given and what you have to name, or let it cycle; distractors come from the same category so you have to discriminate (hypoketotic vs. ketotic hypoglycemia, which GSD, which urea-cycle enzyme…). Every answer shows the whole card with the lecture and slide.
Lysosomal · FMK 01.2
Hurler syndrome (MPS I) Autosomal recessive
Defect / target: Lysosomal GAG-degrading enzymes (Hurler: alpha-L-iduronidase)
Mechanism: GAGs dermatan sulfate and heparan sulfate cannot be degraded and accumulate in lysosomes of connective tissue, cornea, heart and brain; only ~20% enzyme activity is needed to be symptom-free, most patients have <1%.
↑ Accumulates: Glycosaminoglycans (heparan sulfate, dermatan sulfate)· ↓ Deficient: alpha-L-iduronidase (Hurler)
Presentation: normal at birth; progressive coarse facial features (short upturned nose, flat face, prominent forehead, large head, thick lips, large tongue), finger contractures/claw hand, corneal clouding (ground glass), glaucoma, retinal disease, chronic rhinitis/otitis media, cardiomyopathy (most common cause of death), hydrocephalus, developmental delay, gibbus deformity, abnormal clavicles, hip dysplasia, joint stiffness, growth retardation; Hurler most severe (0% enzyme), Hurler-Scheie intermediate, Scheie mildest (no cognitive delay)
Labs: urine screen for dermatan sulfate and heparan sulfate
Treatment: Enzyme replacement, hematopoietic stem cell transplant
Learn the mechanism: Lysosomal card →
FMK 01.2 Proteins, Carbohydrates, Lipids; FMK Protein Targeting & Lysosomal Disorders · slide 01.2: 10; Protein: n/a (Hurler pages)