Osteochondrodysplasia (Scottish Fold cartilage/bone disease)
The TRPV4 mutation that folds a Scottish Fold's ears also disrupts cartilage growth throughout the skeleton, causing shortened or misshapen limb bones, a thickened and inflexible tail, and progressive, often painful degenerative joint disease. A cat needs only one copy of the mutation to have folded ears and be at risk; two copies bring more severe skeletal disease. Because a folded ear cannot exist without at least one copy of the mutation, the appearance and the disease risk cannot be separated by any test.
What to ask for
TRPV4 Scottish Fold genotyping result for both parents (UC Davis VGL), confirming N/SF rather than SF/SF, plus a veterinary orthopaedic assessment of the individual cat — genotyping rules out the more severely affected homozygous form but cannot rule out the disease itself in a fold-eared cat