IDH1 and chondrogenic neoplasm: In the study by Amary et al., 13 of 23 (56.5%) cases of DDCS harbored IDH mutation (12 cases in IDH1 R132C/G/H/L and 1 in IDH2 R172S), and in central low-grade cartilaginous tumours IDH mutations were observed in 52% of cases [78].