There's an increased risk of skin cancer (because of sunburn) on white and lighter colored cats. Since Casper is deaf, you probably won't be letting him outside so skin cancer is not much of a risk for him.
I read once that the risk of a white cat getting skin cancer was one in eight, if they have unlimited access to sunlight, though that must depend ont he part of the world they live in. But I have three white cats and I put children's sunblock on all of them in summer, whetehr they go outside ort not, as they all love sitting in sunny windows and doorways.