What is the purpose for DNA testing of coat color genes?
The information gained from DNA testing of coat color genes is useful in several ways. It can help to define/verify the base color of a horse (particularly if obscured by other genes such as Grey, double Cream Dilution), and to determine the possibility whether a horse can (or cannot) produce certain color(s) in the foals. Based on the DNA test results, the owner has the opportunity to make an educated decision with what mate to breed the horse to increase the probability of getting offspring with a desired color. A special case is testing for the Lethal White Overo gene (LWO/OLWS) to detect carriers of this mutation. Because the mating between two LWO/OLWS carriers has a 25% calculated risk of producing a lethal white foal, conscientious testing for LWO/OLWS is important to minimize/prevent such unfortunate events.
