Maple Syrup Urine Disease (MSUD)

What this deck covers

Maple Syrup Urine Disease (MSUD) in fourteen 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 fourteen cases you are asked to choose between options such as: Maple syrup urine disease (MSUD), Urea cycle disorder, Isovaleric acidemia, Phenylketonuria (PKU), Phenylalanine hydroxylase (PAH), GALT (galactose-1-phosphate uridylyltransferase), OTC (ornithine transcarbamylase), Plasma amino acid analysis, Urine ketones, MRI brain, Intermittent MSUD, Classic MSUD, Intermediate MSUD, Thiamine-responsive MSUD, Low protein diet, Soy formula, BCAA-free medical formula, High calorie diet, Intraventricular haemorrhage, Cerebral oedema, Decorticate posturing, Normal newborn reflex, Simple hyperextension response, Oral thiamine supplementation, Low fat diet initiation, Empirical antibiotics.

Clinical pearls from this deck

• Classic MSUD follows a strikingly consistent timeline: normal at birth, subtle poor feeding by day 1–2, irritability and lethargy by day 3–4, and peak symptoms with the maple syrup odour by days 4–7. This 5-day-old sits exactly in that window.
• The odour comes from sotolone, an isoleucine metabolite whose furanone ring produces the sweet caramel smell. Crucially it is detectable in cerumen before it appears in urine — smelling the earwax can be the earliest bedside clue in a neonate.

The fourteen 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.