| Other Names: | Juvenile Alopecia, Hypotrichiosis |
|---|---|
| Affected Genes: | SGK3 |
| Mutation(s): | rh1 = Chr29:16366702_16366705delTTAG (American Hairless Terrier Type); rh2 = Chr29: 16351976_16351977insT (Scottish Deerhound Type) |
| Breed(s): | American Hairless Terrier, Scottish Deerhound |
Testing Summary
The Hairlessness coat trait test reliably determines if a dog has one of the following genotypes at the SGK3 gene:
| RH/RH | This dog does not carry any copies of the rh1 or rh2 mutations and has a genotype of HR/HR which does not result in hairlessness in the Scottish Deerhound. This dog will pass one copy of HR to 100% of its offspring. Interpretation: Coated |
| RH/rh1 | This dog carries one copy of the rh1 Mutation and has a genotype of RH/rh1 which does not result in hairlessness. This dog will pass one copy of RH to 50% of its offspring and one copy of rh1 to 50% of its offspring. This dog can produce hairless offspring if bred to a dog that is also a Carrier of an rh mutation (RH/rh or rh/rh). Interpretation: Coated (carries hairlessness) |
| RH/rh2 | This dog carries one copy of the rh2 mutation and has a genotype of RH/rh2 which does not result in hairlessness. This dog will pass one copy of RH to 50% of its offspring and one copy of rh2 to 50% of its offspring. This dog can produce hairless offspring if bred to a dog that is also a carrier of an rh mutation (RH/rh or rh/rh). Interpretation: Coated (carries hairlessness) |
| rh1/rh1 | This dog carries two copies of an rh1 mutation which results in hairlessness. This dog will pass one copy of rh1 to 100% of its offspring. Interpretation: Hairless |
| rh2/rh2 | This dog carries two copies of an rh2 mutation which results in hairlessness. This dog will pass one copy of rh2 to 100% of its offspring. Interpretation: Hairless |
| rh1/rh2 | This dog carries one copy of the rh1 mutation and one copy of the rh2 mutation which results in hairlessness. This dog will pass one copy of rh1 to 50% of its offspring and one copy of rh2 to 50% of its offspring. Interpretation: Hairless |
Detailed Summary
The SGK3 gene impacts the presence or absence of coat in the American Hairless Terrier and Scottish Deerhound. SGK3 is critical to proper hair follicle development and maintenance. Variants in this gene cause juvenile hair loss and Alopecia, resulting in a hairless dog.
Testing Tips
Genetic testing of the SGK3 gene will reliably determine whether or not a dog is a genetic Carrier of the rh1 or rh2 variants that cause juvenile Alopecia in the American Hairless Terrier and Scottish Deerhound, respectively. Contrary to the HR Locus which causes hairlessness in the Chinese Crested, variants in the SGK3 gene are inherited in a recessive fashion, meaning that two copies of an rh (recessive hairlessness) variant are required to produce hairlessness. Dogs with one copy of rh or no copies of rh will be coated. However, a dog with two copies of rh will typically be born with sparse hair that will fall out within the first few weeks of life, resulting in hairlessness.
Disclaimer:
There may be other causes of this coat trait in dogs and a normal result does not exclude a different Mutation in this gene or any other gene that may result in a similar genetic trait.
References
- Hytönen MK, Lohi H. A frameshift insertion in SGK3 leads to recessive hairlessness in Scottish Deerhounds: a candidate gene for human alopecia conditions. Hum Genet. 2019 138, 535–539. https://doi.org/10.1007/s00439-019-02005-9
- Parker HG, Harris A, Dreger DL, Davis BW, Ostrander EA. 2017 The bald and the beautiful: hairlessness in domestic dog breeds. Phil. Trans. R. Soc. B 372: 20150488. http://dx.doi.org/10.1098/rstb.2015.0488
