Feline Congenital Erythropoietic Porphyria: Two Homozygous UROS Missense Mutations Cause the Enzyme Deficiency and Porphyrin Accumulation

Table 2 Erythrocyte and plasma porphyrins in the affected proband and WT cats.

Tissue and porphyrin	WT (n = 6), nmol/L tissue^a (range)	Wisconsin (n = 1)
Tissue and porphyrin	WT (n = 6), nmol/L tissue^a (range)	nmol/L Tissue (range)	Fold over WT	Percent of total I + III isomers
Erythrocytes
URO I	0.61 (0.0–1.22)	113	185	41.5
URO III	0.1 (0–0.1)	2.51	25.1	0.9
COPRO I	0.07 (0–0.14)	155	2,210	57.5
COPRO III	0.1 (0–0.1)	ND^b	ND^b	0.0
PROTO IX	ND^b	ND^b	ND^b	ND^b
Plasma
URO I	0.12 (0–0.17)	1,283 (1,123–1,443)	10,700	45.6
URO III	0.10 (0–0.39)	ND^b	ND^b	0.0
COPRO I	0.29 (0.15–0.53)	1,530 (1,376–1,684)	5,280	54.4
COPRO III	0.18 (0.11–0.28)	ND^b	ND^b	0.0

^aNormal values of porphyrins in a liter of packed erythrocytes are as previously published (1).
^bND, not detectable. The limit of detection of porphyrins was 0.1 pmol/g tissue.

ISSN: 1528-3658