COL2A1 and Legg-Calve-Perthes disease: In recent years, a considerable amount of research has been carried out on the etiology of the disease, and the development of the disease is believed to involve a variety of molecular biological alterations, such as the COL2A1 mutation, which may be one of the causes of necrotic collapses of the epiphyseal cartilage matrix in LCPD.