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.
Nucleotide · FMK 08.1
APRT (adenine phosphoribosyltransferase) deficiency Autosomal recessive
Defect / target: Adenine phosphoribosyltransferase (purine salvage: adenine + PRPP -> AMP)
Mechanism: Adenine cannot be salvaged to AMP and is instead oxidized by xanthine oxidase to the very insoluble 2,8-dihydroxyadenine, which precipitates in the urinary tract.
↑ Accumulates: Adenine, 2,8-dihydroxyadenine· ↓ Deficient: Salvaged AMP
Presentation: 2,8-dihydroxyadenine kidney stones; much milder than HGPRT deficiency
Labs: 2,8-dihydroxyadenine crystals/stones
Treatment: Allopurinol
APRT = Adenine; HGPRT = Hypoxanthine + Guanine
Learn the mechanism: Purine synthesis & salvage →
FMK 08.1 Nucleic Acid Metabolism · slide 13