Abstract: Mutations in the gene coding collagen type II α 1 chain (COL2A1 ) are associated with a series of human disorders mainly involving the skeletal system. Here, we describe the second family with COL2A1  mutation, c.611G>C, Gly204Ala, leading to a replacement of glycine in the core triple helical (Gly-X-Y) domain of COL2A1  gene. The replacements of glycine in every third position of the triple with other amino acids will cause failure in the structure of type II collagen. The affected family members manifested early-onset osteoarthritis involving multiple joints. We propose that the COL2A1  gene should be taken into consideration for genetic counseling for patients with hereditary premature osteoarthritis and individuals carrying this mutation should receive early interventions for osteoarthritis.
Keywords: COL2A1 , mutation, early-onset osteoarthritis