In other species: domestic guinea pig

Categories: Homeostasis / metabolism phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 614097 (trait) , 115500 (gene)

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal

Disease-related: yes

Key variant known: yes

Year key variant first reported: 2000

Cross-species summary: Catalase catalyses the decomposition of hydrogen peroxide to oxygen and water. Reduced levels of catalase can lead to hypocatalasemia / hypocatalasaemia or hypocatalasia and absence of catalase activity results in acatalasaemia / acatalasemia.

Molecular basis: By cloning and sequencing a very likely candidate gene (based on knowledge of the biochemical and physiological properties of the enzyme catalase in affected dogs), Nakamura et al. (2000) reported that the canine disorder in Beagles is due to a missense mutation [in the catalase gene (CAT),] leading to the substitution of alanine(327) (GCT) by threonine (ACT)".

Clinical features: Catalase is an enzyme responsible for breaking down reactive oxygen species. As there are other enzymes able to fulfil this role, hypocatalasia often has no clinical signs. Hypocatalasia has been associated with ulcers of the oral cavity leading to gangrene, a condition known as “Takahara disease” in humans (Fukuda et al., 1982). The pathogenesis of this disease is explained by some oral bacteria producing hydrogen peroxide, which is unable to be decomposed due to catalase deficiency (Ogata et al. 2008). IT thanks DVM student Joumana Quinn, who provided the basis of this contribution in May 2023.

Prevalence: Noting that the original discovery of the likely causal variant (c.979G>A; p.Ala327Thr) was in a Beagle colony, Donner et al. (2016) reported that "To our knowledge, presence and manifestation of acatalasemia due to the aforementioned CAT variant has not been previously documented in the pet Beagle population. We therefore note that we identified pet Beagle carriers, and a tenmonth-old mutant homozygous Beagle through panel screening. During this investigation, the genetically affected Beagle developed gangrene of the oral cavity leading to the removal of three teeth at the age of eighteen months, which could be a manifestation of acatalasemia". Donner et al. (2016, 2018) reported additional breeds in which the c.979G>A; p.Ala327Thr variant was present: American Foxhound (n=1), English Foxhound (n=1), Harrier 9 (n=6), Miniature Poodle (n=1), Treeing Walker Coonhound (n=2).

Breeds: American Foxhound (Dog) (VBO_0200047), Beagle (Dog) (VBO_0200131), English Foxhound (Dog) (VBO_0200490), Harrier (Dog) (VBO_0200660), Poodle, Miniature (Dog) (VBO_0201051), Treeing Walker Coonhound (Dog) (VBO_0201374).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene: