Disorder | Defective Enzyme/Transporter | Clinical Picture | Mnemonic |
---|---|---|---|
Phenylketonuria (PKU) | Phenylalanine hydroxylase | Musty body odor, intellectual disability, seizures, pale skin, eczema | Pale kids with Krappy Urine |
Alkaptonuria | Homogentisic acid oxidase | Black urine, ochronosis (bluish-black pigmentation in connective tissues), arthritis | Black CAP: Cartilage, Arthritis, Pigmentation |
Maple Syrup Urine Disease (MSUD) | Branched-chain α-ketoacid dehydrogenase | Sweet-smelling urine, poor feeding, vomiting, lethargy, developmental delays | I LoVe Maple Syrup: Isoleucine, Leucine, Valine |
Homocystinuria | Cystathionine β-synthase | Lens dislocation, marfanoid habitus, intellectual disability, thromboembolism | HOMOCY: Homocysteine in urine, Osteoporosis, Marfanoid, Ocular issues, CV risk, Younger thrombus |
Tyrosinemia Type I | Fumarylacetoacetate hydrolase | Liver and kidney failure, cabbage-like odor, failure to thrive | Tyrosine in liver is toxic |
Cystinuria | Defective renal reabsorption of cystine | Recurrent kidney stones (cystine crystals) | COLA: Cystine, Ornithine, Lysine, Arginine |
Argininosuccinic Aciduria | Argininosuccinate lyase | Hyperammonemia, lethargy, seizures, growth delays | Arginine Stops (succinate) ammonia buildup |
Ornithine Transcarbamylase (OTC) Deficiency | Ornithine transcarbamylase | Hyperammonemia, orotic acid in urine, lethargy, vomiting, confusion | OTC: Orotic acid, Toxic ammonia, Confusion |
Hartnup Disease | Defective neutral amino acid transporter | Photosensitivity, ataxia, rash resembling pellagra (niacin deficiency due to tryptophan loss) | HART: High-light sensitive, Ataxia, Rash, Tryptophan loss |
Primary Hyperoxaluria | Glyoxylate aminotransferase | Recurrent calcium oxalate kidney stones, renal failure, systemic oxalosis | OX: Excess oxalate leads to Systemic Oxalosis |