Table 2

The porphyrias: patterns of overproduction of haem precursors

	Urine
Disorder	PBG/ALA	Porphyrins	Faecal porphyrins	Erythrocyte porphyrins	Plasma fluorescence emission peak
*Total porphyrins may be increased due to presence of excess uroporphyrin.⁶
†PBG and ALA excretion may be normal when only skin lesions are present.
‡Hexacarboxylix and pentacarboxylic porphyrins and coproporphyrin are increased to a smaller extent. Uroporphyrin is a mixture of type I and III isomers; heptacarboxylic porphyrin is mainly type III.
ALA, 5-aminolevulinate; PBG, porphobilinogen.
ALA dehydratase deficiency	ALA	Copro III	Not increased	Zn–proto	–
Acute intermittent porphyria	PBG > ALA	(porphyrin mainly from PBG)	Normal, or occasional slight increase in copro, proto*	Not increased	615–620 nm
Congenital erythropoietic porphyria	Not increased	Uro I, Copro I	Copro I	Zn–proto, proto	615–620 nm
				Copro I, Uro I
Porphyria cutanea tarda	Not increased	Uro, Hepta‡	Isocopro, Hepta‡	Not increased	615–620 nm
Hereditary coproporphyria	PBG > ALA†	Copro III	Copro III	Not increased	615–620 nm
		(porphyrin from PBG)
Variegate porphyria	PBG > ALA†	Copro III	Proto IX > Copro III, X porphyrin	Not increased	624–627 nm
		(porphyrin from PBG)
Erythropoietic protoporphyria	Not increased	Not increased	± Protoporphyrin	Protoporphyrin	626–634 nm