Medium-Chain Acyl-CoA Dehydrogenase Deficiency (MCAD)

What this deck covers

Medium-Chain Acyl-CoA Dehydrogenase Deficiency (MCAD) in twelve clinical teaching cases with worked explanations. Each case gives you a clinical vignette, four options, the correct answer, and an explanation of why each of the other three is wrong.

Diagnoses and management options tested

Across the twelve cases you are asked to choose between options such as: High dietary fat intake causing lipid overload, Excess protein catabolism from muscle breakdown, Prolonged fasting depleting glycogen stores during illness, Mitochondrial toxicity from viral replication, Elevated urinary ketones with normal glucose, Metabolic alkalosis with hyperammonemia, Hypoketotic hypoglycaemia with elevated acylcarnitines, Lactic acidosis with elevated pyruvate, Generalised lymphadenopathy and splenomegaly, Hepatomegaly with hypotonia and depressed consciousness, Peripheral oedema and distended neck veins, Petechial rash and bulging fontanelle, PAH gene mutation; autosomal recessive, HADHA gene mutation; X-linked recessive, ACADM gene mutation; autosomal recessive, ETFDH gene mutation; autosomal dominant, Propionylcarnitine (C3), Palmitoylcarnitine (C16), Octanoylcarnitine (C8), Isovalerylcarnitine (C5), Fluorescent immunoassay of whole blood proteins, Urine organic acid chromatography, Liver biopsy to assess fatty infiltration, Elevated liver transaminases (AST/ALT), Elevated C8-acylcarnitine with inappropriately low ketones, Hypoglycaemia with high urine ketone levels.

Clinical pearls from this deck

• The trigger is always the fast, never the food. Illness depletes glycogen within hours, the body switches to fat oxidation, and the MCAD block stops medium-chain fats being burned. No ketones are produced, so the brain loses its backup fuel and hypoketotic hypoglycaemia follows. Peak risk is 2–24 months.
• Hypoketotic hypoglycaemia is the defining signature — low glucose with inappropriately absent ketones, plus elevated C6–C12 acylcarnitines. In normal fasting, ketones rise to protect the brain; in MCAD that safety net simply is not there.

The twelve worked cases in this deck, with the images and the full explanation of every option, are part of Pediatric Case Review membership. See what is included.

More from this system: all metabolic and genetic decks and question sets · pediatric reference values.