ADMED can be due to; COMP (cartilage oligomeric matrix protein), COL9A1-COL9A3 (collagen type IX alpha 1–3 chain) or MATN3 (matrilin 3) and presents in childhood with joint pain, exercise-induced fatigue, restricted mobility, short stature, and early-onset osteoarthritis [18]. The gene discussed is COL9A3; the disease is osteoarthritis.