Genetic markers of canine hip dysplasia

Canine hip dysplasia is a complex skeletal malformation caused by genetic and environmental factors. The prevalence of hip dysplasia in different canine breeds ranges widely, from 1% (for Whippet and Borzoi) to over 70% (for Bulldog and Pug). These differences indicate the presence of genetic variants predisposing to or preventing this disorder in gene pools of particular breeds. The importance of genetic factors is also confirmed by a high coefficient of heritability (h2) of canine hip dysplasia, which for most breeds oscillates around 0.5 – 0.6. Application of modern genomic methods, that is, mainly genome scanning (based previously on microsatellite markers and currently on SNP microarrays) has led in recent years to the identification of potential genetic markers associated with this disorder. Such studies were carried out mostly in two breeds: Labrador retriever and German shepherd. Some of the markers were found in the vicinity of genes involved in skeletal development. Following these achievements, the use of some markers has been suggested for early risk diagnosis of hip dysplasia. This shows that molecular testing is becoming important for not only monogenic, but also polygenic canine diseases and disorders. Identification of genetic markers associated with predisposition to hip dysplasia offers an opportunity for an early risk evaluation of this disorder (prior to its first signs). Moreover, it facilitates effective breeding selection aimed at eradicating undesirable genetic variants from the gene pool of a given breed..