The University of Liège has identified the mutation responsible for the genetic defect CDH (Cholesterol Deficit Haplotype) in the Holstein Friesian dairy population.

Thanks to this discovery this genetic defect can now be eradicated with the highest accuracy. The discovery of the causative mutation means in practice that animals can now be tested whether they are carrier with a reliability of 100%. An important step in reducing the incidence of this – still recently discovered – genetic defect. From haplotype to causative mutation CDH is a genetic defect that causes early mortality of young calves. In the summer of 2015 the existence of CDH was made public by the German animal information center vit (IT Solutions for Animal Production), who discovered the haplotype for CDH (part of the chromosome where the responsible gene should be present). The available haplotype test which was developed in order to identify carriers of this defect has a reliability lower than 100%. With knowledge about the haplotype and a list of known carriers, the researchers of the University of Liège were able to identify the corresponding causative mutation. This research was also made possible by herd improvement organization CRV who provided the DNA samples. Having identified the mutation, the University of Liège can now test animals for CDH with – as mentioned above – a reliability of 100%, avoiding the unnecessary culling of false positive animals. This direct test will be made accessible to the market for commercial use at the Unit of Animal Genomics (University of Liège, GIGA-R). The corresponding information – including sample type and price details – can be downloaded at: http://www.giga.ulg.ac.be/cms/c_20697/en/unit-of-animal-genomics-diagnostics The identification of the ‘cholesterol deficit’ causative mutation shows the effectiveness of DNA technology in the identification and eradication of hereditary diseases. The co-operation with chain partners was of great help to speed up this process.