GDF5 and obesity due to melanocortin 4 receptor deficiency: In the present study, the effect of obesity on the association of the rs143384 GDF5 with KOA was shown: allele G of this SNP was a KOA protective factor in individuals with BMI ≥ 30 (OR 0.41) and disease risk marker in individuals with BMI < 30 (OR 1.32–1.67).