Description: Enamel formation is a strictly regulated process in which various genes and their products are involved. Mutations in any of them can result in defective development. Amelogenesis imperfecta (AI) is an inherited tooth disease affecting the structure, composition, and amount of enamel formed in the process of amelogenesis. Non-syndromic and syndromic forms are known, and several genes responsible for various aspects of enamel physiology have been described. Non-syndromic AI also occurs spontaneously in dogs with known autosomal recessive variants in the ACP4 (Hytönen et al., 2019), ENAM (Gandolfi et al., 2013; Hytönen et al., 2019), and SLC24A4 (Pedersen et al., 2017) genes. Affected dogs have a rough tooth surface with brown spots in places where the enamel is thin or completely absent. Their teeth can be smaller, and pointed, with large gaps between the individual teeth. They are more prone to dental plaque, fractures, gingivitis, pulpitis, or other periodontal diseases.

The ACP4 gene belongs to the superfamily of histidine phosphatases (acid phosphatases). They are enzymes catalyzing the hydrolysis of phosphate esters in acidic conditions. The ACP4 gene was originally referred to as ACPT (testicular acid phosphatase) because it is highly expressed in the testes. In addition, however, it is also expressed in the skin and in the brain, where it is important for the development of neurons and synaptic plasticity. It has been shown that ACPT is also expressed in odontoblasts, osteoblasts, and in secretory ameloblasts, but its function in tooth development is not yet clear enough. It is thought to play a role in the secretory phase of amelogenesis, odontoblast differentiation, and dentin mineralization by supplying phosphate.

Inheritance: autosomal recessive

Mutation: 1 bp insertion c.1189dupG (p.Ala397Glyfs) in ACP4 gene

Sample: EDTA whole blood (1.0 ml) or 2 buccal brushes

The analysis is suitable for the following breeds: Akita Inu, American Akita

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