Table 2: Fatty acid oxidation disorders and biochemical characteristics.

DisorderBiochemical characteristics

Carnitine uptake defect (CUD)
(Primary/systemic carnitine deficiency, carnitine transporter OCTN2 deficiency)
Carnitine (P)
Carnitine palmitoyltransferase I deficiency (CPT 1A)↑ Ammonia (P)
↑ Liver enzymes (ALT, AST)
Carnitine palmitoyltransferase II deficiency (CPT II) 
(i) lethal neonatal
(ii) infantile
(iii) myopathic
↑ C12–C18 acylcarnitines (P)
Carnitine-acylcarnitine translocase deficiency (CACT)↑ Ammonia (P)
↑ Liver enzymes (ALT, AST)
↑ Creatine kinase (P)
↑ Long chain acylcarnitines (P)
Free carnitine (P)
Mitochondrial trifunction protein deficiency (TFP) 
(i) Isolated long chain Acyl-CoA
Dehydrogenase deficiency (LCHAD)
Hypoketotic hypoglycemia
Very long chain acyl-CoA dehydrogenase deficiency (VLCAD)Hypoglycemia (ketotic or nonketotic)
Medium chain acyl-CoA dehydrogenase deficiency (MCAD)Hypoketotic hypoglycemia
Medium chain 3-ketoacyl-CoA thiolase deficiency (MCKAT)Ketotic lactic aciduria
C6–C12 dicarboxylic aciduria
Short chain acyl-CoA dehydrogenase deficiency (SCAD)↑ Ethylmalonic acid (U)
Medium/short chain acyl-CoA dehydrogenase deficiency (M/SCHAD) Hyperinsulinemic hypoglycemia
↑ 3-Hydroxybutylcarnitine
↑ 3-Hydroxy butyric acid (U)
↑ 3-Hydroxy glutaric acid (U)
Glutaric acidemia Type IIHypoglycemia
Metabolic acidosis
2,4-Dienoyl-CoA reductase deficiency2-Trans,4-Cis-decadienoylcarnitine (P, U)
Acyl-CoA dehydrogenase 9 deficiency (ACAD9)Persistent lactic acidosis