Bone disorders in the dog: A review of modern genetic strategies to find the underlying causes

In man, the genetic defects of more than 600 inherited diseases, of which a t least 150 skeletal diseases, have been identified as is the chromosomal l ocation for approximately 7000 genes. This rapid progress has been made pos sible by the generation of a genetical and physical map of the human genome . There is no reason to believe that for the dog not a similar development may occur, This review is therefore focussed on the use of novel tools now available for comparative molecular genetic studies of skeletal dysplasias in the dog. Because the genomes of mammals at the subchromosomal level are very well conserved, likely candidate disease genes known from other specie s might be considered. In this review, formation of the bones and the most important canine disorders of the skeleton influencing locomotion will be d iscussed first. The canine disorders discussed are canine hip dysplasia, th e three different forms of elbow dysplasia (fragmented coronoid process, un united anconeal process, osteochondrosis dissecans and incongruency) and dw arfism, Where possible a link is made with similar diseases in man or mouse . Then, the molecular biological tools available to analyse the genetic def ect will be reviewed and some examples discussed.