Table 1: Amino acidemias and organic acidopathies.

DisorderDefective enzymeDiagnostic metabolites

Propionic acidemia (PA)Propionyl CoA carboxylase
Propionylcarnitine (C3; P)* 
Methylcitrate (U)* 
3-Hydroxypropionic acid (U)
Methylmalonic acidemia (MMA)Methylmalonic mutase
Cobalamin A
Cobalamin B
Methylmalonic acid (P, U)
Propionylcarnitine (C3; P)
Methylcitrate (U)
3-Hydroxypropionic acid
Methylmalonic acidemia with homocysteinuria, cobalamin C/DCobalamin C
Cobalamin D
Methylmalonic acid (P, U)
Propionylcarnitine (C3; P)
Methylcitrate (U)
Total homocysteine (P)
3-Hydroxypropionic acid (U)
Isovaleric acidemia (IVA) Isovaleryl dehydrogenaseIsovaleric acid (U)
Isovalerylcarnitine (C5; P)
3-Methylcrotonylglycinuria (3MCC) 3-Methylcrontonyl
CoA carboxylase
3-Hydroxyisovaleric acid (U)
3-Methylcrotonylglycine (U)
Hydroxyisovalerylcarnitine (C5OH; P)
3-Hydroxy-3-methylglutaryl CoA lyase deficiency3-Hydroxy-3-methyl-
glutaryl CoA Lyase
Hydroxyisovalerylcarnitine (C5OH; P)
3-Hydroxy-3-methylglutaric acid (U)
3-Methylglutaconic acid (U)
Malonic aciduriaMalonyl CoA decarboxylaseMalonate (U)
2-Methyl-3-hydroxybutyrl CoA dehydrogenase deficiency2-Methyl-3-hydroxybutyryl
CoA dehydrogenase
2-Methyl-3-hydroxybutyrate (U)
Tiglylglycine (U)
Ethylmalonic encephalopathyBranched chain Keto-dehydrogenaseC4
C5
Ethylmalonic acid (U)
Methylsuccinic acid
C4–C6 acylglycines (P)
Beta-ketothiolase deficiency3-Methyl acetoacetate
thiolase
C5:1 (P)
2-Methyl-3-hydroxybutyrate (U)
Tiglylglycine (U)
2-Methyacetoacetate (U)
Biotinidase deficiency and Holocarboxylase synthetase deficiencyBiotinidase
Holocarboxylase synthetase
Propionylcarnitine (C3; P)
Hydroxyisovalerylcarnitine (C5OH; P)
Biotinidase enzyme deficiency (P)
Lactate (P, U)
3-Methylcrotonylglycine (U)
Methylcitrate (U)
3-Hydroxypropionic acid (U)
2-Methyl butyryl CoA dehydrogenase 2-Methyl butyryl CoA dehydrogenase2-Methylglycience (U)
Isovalerylcarnitine (C5; P)
Glutaric acidemia IGlutaryl CoA dehydrogenaseGlutaric acid (U)
3-Hydroxyglutaric acid (U)
Glutaryl carnitine (C5-DC; P)
3-Methylglutaconic acidurias 3-Methylglutaconyl CoA 
hydratase (Type I)
Barth (Type II)
Costeff (Type III)
Type IV
Type V
3-Methylglutaconic acid (U)
Hydroxy-isovalerylcarnitine (P)
Canavan diseaseAspartoacylaseN-Acetylaspartic Acid (U)
L-2-Hydroxyglutaric aciduriaL-2-Hydroxyglutarate dehydrogenaseL-2-Hydroxyglutaric Acid (U)
Lysine (CSF)
D-2-Hydroxyglutaric aciduriaD-2-Hydroxyglutarate dehydrogenase
Hydroxy-oxoacid
transhydrogenase
D-2-Hydroxyglutaric acid (U)
4-Hydroxybutyric AciduriaSuccinate semialdehyde dehydrogenaseGamma-hydroxybutric acid (U)
Fumaric aciduriaFumarate hydrataseFumarate (U)
Maple syrup urine disease (MSUD)Branched chain Keto-dehydrogenaseLeucine (P)
Alloisoleucine (P)
Dicarboxylic acids (U)
Dihydrolipoamide dehydrogenaseMSUD IIILeucine (P)
Alloisoleucine (P)
Dicarboxylic acids (U)
Lactic acid (P, U)
Phenylketonuria (PKU)Phenylalanine hydratase (PAH)Phenylalanine (P)
Low tyrosine (P)

(P): plasma, (U): urine. Adapted from Pearl [2].