Deutsch
Hrvatski
Русский
Português
Ehlers-Danlos Syndrome (variants 1 and 2)
| Acronym: | EDS |
| Gene: | TNXB |
| Mutation: | g.1499124C>T, g.1490385C>T |
| Inheritance: | Autosomal Recessive |
| Sample type: | CHS (Cheek Swab), WBE (Whole Blood EDTA) |
Genetics and characteristics
Ehlers-Danlos syndromes (EDS) are a group of heritable connective tissue disorders caused by genetic defects in 20 different genes and reported in various animals and humans. EDSs are characterized by skin hyperextensibility, joint hypermobility, and generalized tissue fragility and may include potentially life-threatening cardiovascular, musculoskeletal and other organ complications. All of the genes whose mutations cause the disease are involved in the biosynthesis and/or fibrillogenesis of collagens at some level. The type of EDS found in dogs is caused by two mutations in the TNXB gene and hence, two variants are identified. Both mutations are point mutations resulting in a non-functional extracellular matrix protein that regulates regulate collagen deposition.
These connective tissue disorders in dogs are inherited as an autosomal recessive trait meaning two copies of the mutated gene for the disease to develop. However, there have been few cases reported of dogs who were heterozygous for TNXB genetic variants, carrying one mutated and one normal copy of the gene, and developed a milder form of EDS. Early detection by genetic testing can identify carriers and help breeders in selecting future mating pairs.
Results Reported As
Test Result |
Interpretation of test result |
CLEAR |
Tested mutation was not detected in animal with „clear“ result. Animal tested as clear has wild-type allele in homozygous state (i.e. two pairs of healthy alleles). It will not develop disease caused by tested mutation.* It will pass only wild-type allele to its offspring. |
CARRIER |
Tested mutation was detected in animal with „carrier“ result. Animal tested as carrier has one wild-type and one mutation allele, it is in heterozygous state. It will not develop disease caused by tested mutation.* It can pass wild-type or mutation allele to its offspring. |
AFFECTED |
Tested mutation was detected in animal with „affected“ result. Animal tested as affected has two copies of mutation alleles affecting the gene. It is likely the animal will experience a genetic disorder due to this mutation.** It will pass only mutation allele to its offspring. |
*Test excludes only tested mutation but not possible unknown mutations or factors that can lead to similar condition/symptoms.
** Potential unknown mutations or multiple other factors can possibly affect the likelihood of experiencing a genetic disorder.
References:
Bauer, A., de Lucia, M., Leuthard, F., Jagannathan, V. and Leeb, T. (2019), Compound heterozygosity for TNXB genetic variants in a mixed-breed dog with Ehlers-Danlos syndrome. Anim Genet, 50: 546-549. https://doi.org/10.1111/age.12830
Vroman, R., Malfait, A.M., Miller, R.E., Malfait, F., Syx, D. Animal models of Ehlers-Danlos syndromes: Phenotype, pathogenesis, and translational potential. Front Genet 12:726474, 2021. Pubmed reference: 34712265. DOI: 10.3389/fgene.2021.726474.