Microsomal triglyceride transfer protein
MTTP
Fat malabsorption, acanthocytosis, retinitis pigmentosa, ataxia, fat-soluble vitamin deficiency
Metabolic disorders
Inborn errors and acquired disorders mapped to the pathway and enzyme they affect.
Porphobilinogen deaminase (HMBS)
HMBS
Abdominal pain, neuropathy, psychiatric signs, port-wine urine; NO photosensitivity; triggered by CYP inducers, fasting, alcohol
Adenosine deaminase
Severe combined immunodeficiency; absent T, B and NK cells
Alkaptonuria
AR
Homogentisate 1,2-dioxygenase
HGD
Urine darkens on standing, ochronosis of cartilage, degenerative arthritis
Glycogen branching enzyme
Cirrhosis, failure to thrive, early death
Argininosuccinate lyase
ASL Urea Cycle
Hyperammonaemia, trichorrhexis nodosa (brittle hair)
Argininosuccinate synthetase
ASS1 Urea Cycle
Hyperammonaemia, vomiting, encephalopathy
Galactose-1-phosphate uridylyltransferase
GALT Galactose Metabolism
Cataracts, jaundice, hepatomegaly, intellectual disability, E. coli sepsis
Glycogen debranching enzyme
Milder than GSD I; normal lactate, hepatomegaly, myopathy
Carbamoyl phosphate synthetase I
CPS1 Urea Cycle
Neonatal hyperammonaemia, lethargy, coma
Carnitine palmitoyltransferase I
CPT1A
Hypoketotic hypoglycaemia, hepatomegaly; normal or high carnitine
Carnitine palmitoyltransferase II
CPT2
Adult form: rhabdomyolysis after prolonged exercise or fasting
UGT1A1 (absent)
UGT1A1
Severe neonatal jaundice, kernicterus, death without transplant
Cyanide / carbon monoxide poisoning
Acquired
Complex IV (cytochrome c oxidase) inhibition
(acquired) Electron Transport Chain (Com…
Headache, coma, lactic acidosis; cherry-red skin in CO; bitter-almond odour in cyanide
Cystinuria
AR
Dibasic amino acid transporter (COLA)
SLC3A1 / SLC7A9
Recurrent hexagonal cystine kidney stones