Relevance Rating: There is some evidence or research available for these breeds
Relevance Rating: The test is unknown, there is no evidence (i.e. research) available, or it has not been evaluated yet. These tests may or may not be meaningful for these breeds
The variants are fixed in some breeds, so breeding away without an outcross would be impossible
In summary, our study strengthens the role of the DVL2 variant in the brachycephalic phenotype and caudal vertebral anomalies, and suggests that other conditions may be linked to canine Robinow-like syndrome, including BOAS and congenital heart defects. Kinked tail is an undesired trait in non-screw tail breeds and our study shows that screening of the DVL2 variant could help to redesign breeding plans to reduce unwanted DVL2-related anomalies and improve canine welfare....The DVL2 variant was completely fixed in Boston Terriers, French Bulldogs and English Bulldogs. Deletion homozygotes and heterozygotes were additionally discovered in ASTs and SBTs. Furthermore, heterozygotes were found in Dogues de Bordeaux, Olde English Bulldogges and American Bulldogs. Overall, the carrier frequency in these five breed cohorts ranged from 18.2% to 50.0%; however, sample sizes were highly variable (from 4 to 708). Finally, the variant was absent in the seven other breeds.[Niskanen et al, 2021]
The DVL2 variant appears to be associated with the "screw tail" (short, kinked tail) in a number of dog breeds/types. This variant may also be related to a Robinow-like syndrome, characterised by wide heads, flat caese and short-limbed dwarfism. The research establishes the likelihood that the variant is associated with caudal vertebral malformations (e.g. screw tail) and a brachycephalic conformation. There is some indication that this further links to brachycephalic obstructive airway syndrome and congenital heart defects. Screw-tail is an undesired trait in non-screw tail breeds, therefore screening of the DVL2 variant could help breeding plans to reduce unwanted DVL2-related risks. (ref. Niskanen et al. 2021) Inheritance pattern is suggested to be autosomal dominant, with incomplete penetrance, but in some breeds the variant may be fixed. While all indications appear that the DVL2 variant is important for screw-tail and likely risk-associated with brachycephalic conformation the severity of clinical signs may vary with breeds and individual dogs.
2018 Mansour, T.A., Lucot, K., Konopelski, S.E., Dickinson, P.J., Sturges, B.K., Vernau, K.L., Choi, S., Stern, J.A., Thomasy, S.M., Döring, S., Verstraete, F.J.M., Johnson, E.G., York, D., Rebhun, R.B., Ho, H.H., Brown, C.T., Bannasch, D.L. : Whole genome variant association across 100 dogs identifies a frame shift mutation in DISHEVELLED 2 which contributes to Robinow-like syndrome in Bulldogs and related screw tail dog breeds. PLoS Genet 14:e1007850, 2018. Pubmed reference: 30521570. DOI: 10.1371/journal.pgen.1007850.
2021 Niskanen, J.E., Reunanen, V., Salonen, M., Bannasch, D., Lappalainen, A.K., Lohi, H., Hytönen, M.K. : Canine DVL2 variant contributes to brachycephalic phenotype and caudal vertebral anomalies. Hum Genet 140:1535-1545, 2021. Pubmed reference: 33599851. DOI: 10.1007/s00439-021-02261-8.
Breed Specific Info
American Bulldog, American Staffordshire Terrier, Boston Terrier, Dogue de Bordeaux, English Bulldog, French Bulldog, Staffordshire Bull Terrier