In other species: domestic cat , pig , cattle

Possibly relevant human trait(s) and/or gene(s) (MIM number): 263700 (trait)

Mendelian trait/disorder: unknown

Considered a defect: yes

Cross-species summary: Porphyrins are a class of organic compounds characterised by four pyrrole nuclei connected in a ring structure. When combined with iron, porphyrins form haem, which is a component of haemoglobin, cytochromes, catalases and peroxidases. Thus, porphyrins are constituents of many compounds that play a vital role in biological systems. The biosynthesis of porphyrins involves a six-step process, starting with aminolaevulinic acid (ALA) and ending with protoporphyrin. Each step is catalysed by an enzyme. A deficiency of any one of these enzymes results in a buildup of intermediates prior to the step for which the enzyme is lacking, and a deficiency of intermediates after that step. In much of the literature, these intermediates are loosely called porphyrins. Congenital eryhtropoietic porphyria results from a deficiency of the third enzyme, uroporphyrinogen III cosynthetase, and a consequent buildup of intermediates (i.e. a buildup of porphyrins) that have been synthesised in the three previous steps.

Species-specific description: Queiroz et al. (2021) describe "a presumptive case of CEP in a Gir calf based on clinical and pathological findings. An intron 8 single-nucleotide polymorphism (SNP) in both the Gir calf and control animals, along with the absence of the uroporphyrin III synthetase (UROS) gene mutation, was observed."

Clinical features: Queiroz et al. (2021): "A 3-day-old Gir calf showed teeth discoloration, fever, dehydration, and dyspnea."

Pathology: Queiroz et al. (2021): "The main gross findings were pink-colored teeth, red-brown periosteum and bone marrow, and a fluorescent bright pink coloration of the bone marrow and articular surfaces under ultraviolet light. Aggregates of periodic acid-Schiff (PAS)-stained porphyrin pigments were evident in the lungs, kidneys, and the liver."

Breed: Gir.