Mild spondyloepiphyseal dysplasia due to COL2A1 mutation with early-onset osteoarthritis is a type 2 collagen-related bone disorder characterized by precocious, generalized osteoarthritis (with onset as early as childhood) and mild, dysplastic spinal changes (flattening of vertebrae, irregular endplates and wedge-shaped deformities) resulting in a mildly short trunk.

Autosomal dominant multiple epiphyseal dysplasia (MED) presents in early childhood, usually with pain in the hips and/or knees after exercise. Affected children complain of fatigue with long-distance walking. Waddling gait may be present. Adult height is either in the lower range of normal or mildly shortened. The limbs are relatively short in comparison to the trunk. Pain and joint deformity progress, resulting in early-onset osteoarthritis, particularly of the large weight-bearing joints.