Final summary update from the end of year 3 of research underway by Dr. Iivanainen of University of Helsinki to hopefully lead to a genetic test to aid breeders in controlling hip dysplasia. Research revealed 30 markers on eight different chromosomes that suggestively associated with the disease.
The overall objective of our study is to perform a genome wide association study (GWAS) of canine hip dysplasia (CHD) in German Shepherds using a large sample cohort (200 cases and
200 controls). CHD is a common problem in many breeds. The dysplasia phenotype is graded from radiographs. In this study, we use the standards of Fédération Cynologique Internationale (FCI) ranging from A (healthy) to E (severely dysplastic). Each hip joint is graded individually.
As the disease progresses also the risk for hip joint arthrosis – a painful and incurable condition – increases. The identification of genetic risk factors would enable the development
of genetic tests to aid the breeders in controlling the disease. Four hundred animals consisting of carefully matched pairs of healthy and affected individuals should provide enough power for the association study to uncover the major genetic risk factors for this degenerative disease.
We have collected a large single-breed study cohort of 1141 German Shepherds including 411 cases and matched controls plus additional 319 controls. We have analyzed the association of CHD to a genome wide array of genetic markers using a subset of these dogs (N=497). The study revealed ca. 30 markers on eight different chromosomes that suggestively associated
with the disease. Targeted replication studies using independent cohorts of dogs (German Shepherds N=244 and 11 breeds N=1767) have validated the findings from 3 chromosomes.
We are currently preparing several manuscripts based on our findings. The preliminary results were presented in the European Human Genetics Conference in Barcelona, Spain, on May