IDH1 and Ollier disease: Recent studies show some evidence regarding etiology of the enchondromas, which is physis growth abnormality related to the PTHR1 and IDH1/2 gene mutation.[9–11] Enchondromatosis or Ollier disease is a rare congenital disorder characterized by multiple enchondromas that may present with shortening, enlargement, and various deformities of the affected bones.[3,5–7,9,10]