Congenital erythropoietic porphyria / CEP 2 variants (UROS-related) - Cat

CEP and haem synthesis in cats

This genetic analysis examines two UROS variants, c.140C>T and c.331G>A, jointly involved in congenital erythropoietic porphyria (CEP) in cats. CEP is an inherited disorder of haem synthesis in which porphyrins accumulate because uroporphyrinogen III synthase functions poorly.

Typical visible signs include reddish-brown urine and brownish discoloured teeth that can fluoresce pink under UV light. The test helps distinguish CEP from other feline porphyrias, such as acute intermittent porphyria.

Practical value of this test

• Determines whether the cat does not carry, carries or is homozygous for the two tested UROS markers.
• Supports breeding selection in lines where porphyria-like signs occur.
• Helps targeted interpretation when brown teeth or reddish-brown urine are observed.

CEP follows an autosomal recessive mode of inheritance. Because the described feline variant consists of two UROS changes assessed together, the combination of both subanalyses is important for the final interpretation.