GM1 gangliosidosis
SeriousVery rare in this breed
A separate mutation, in the GLB1 gene, causes a related but distinct fatal storage disease. In the cats in which it has been studied, onset is around 3 months of age, reaching a terminal stage — including blindness and seizures — by 9 to 10 months; progression is slower than GM2 but equally fatal. The same GLB1 variant is found in Siamese cats, but the Korat is a separate, natural Thai breed, not one founded on the Siamese. In the Korat the disease has been described in a single cat, which fell ill at seven months, worsened slowly and was put to sleep at 21 months; that cat was never DNA-tested, and a 2022 screen of over 11,000 cats found the variant in none of 51 Korats.