Furthermore EDM1, another subgroup of multiple epiphyseal dysplasia, and pseudochondroplasia are linked to defects in cartilage oligomeric matrix protein (COMP) [48] and share pathogenesis with EDM2 [49], suggesting that COMP and CIX are interacting in the large polymeric network of cartilage. Here, COL9A2 is linked to multiple epiphyseal dysplasia.