 Many of the worst, like PKD in Persians, Hip Dysplasia in British Shorthairs and Maine Coons, HCM in Maine Coons, Persians, Exotic Shorthair, British Shorthair, Norwegian Forest Cat, Ragdoll and Bengal, are still present in high frequencies.The frequency of HCM in British Shorthairs are 2.1% for females and 20.4% for males.The frequency of Hip Dysplacia in Maine Coons is 36,3%  or 30.2%.