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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.
Heme · FMK 08.4
ALA dehydratase deficiency porphyria Autosomal recessive
Defect / target: ALA dehydratase (porphobilinogen synthase, ALAD) - step 2
Mechanism: Deficient conversion of two ALA molecules to PBG causes ALA to accumulate before tetrapyrrole ring closure, producing a neurovisceral picture like AIP without photosensitivity.
↑ Accumulates: delta-Aminolevulinic acid (ALA)· ↓ Deficient: Porphobilinogen and downstream heme
Presentation: Acute neurovisceral attacks (abdominal pain, neuropathy, psychiatric symptoms), no photosensitivity; very rare
Labs: Elevated urinary ALA with normal PBG (biochemically resembles lead poisoning)
Treatment: Hemin, glucose, avoid precipitants (as for acute porphyrias)
Sits in the 'before ring closure' zone = neurovisceral only
Learn the mechanism: Heme synthesis (porphyrias) →
FMK 08.4 Heme Metabolism · slide 14-15