SLC26A2 (p.R279W, c.-26+2T>C, p.C653S, p.V340del, p.R178X) is a disorder of cartilage and bone development primarily affecting the ends of the long bones in the arms and legs (epiphyses). Symptoms can include joint pain that most commonly affects the hips and knees, early-onset arthritis, and a waddling walk.