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.
Amino acid · FMK 07.2
Maple syrup urine disease (MSUD) Autosomal recessive
Defect / target: Branched-chain α-ketoacid dehydrogenase (BCKD) complex — partial or complete deficiency (a PDH-like multienzyme complex)
Mechanism: Oxidative decarboxylation of all three branched-chain α-ketoacids is blocked by one shared complex, so leucine, isoleucine, valine and their ketoacids accumulate simultaneously; leucine is neurotoxic.
↑ Accumulates: Leucine, isoleucine, valine and their branched-chain α-ketoacids
Presentation: Feeding problems, ketoacidosis, altered muscle tone, coma (from elevated leucine), maple-syrup urine odor (from isoleucine); fatal if untreated; intellectual disability if treatment delayed
Labs: Newborn screening; elevated plasma BCAAs and ketoacids; ketoacidosis
Treatment: Synthetic BCAA-free formula with limited Leu/Ile/Val — enough for growth, not enough for toxicity
One complex handles all three BCAAs; odor from isoleucine, coma from leucine
AR (~1:185,000)
Learn the mechanism: PDH & TCA cycle →
FMK 07.2 Amino Acid Metabolism II; FMK 02.4 Mitochondrial Metabolism and Energy Disorders · slide 07.2: 07.2: 14, 15; 07.1: 29, 33; 02.4: 18