The Japanese population has shown a higher incidence of osteoarthritis in patients with intronic and core promoter single nucleotide polymorphism (SNP) in the CALM-1 gene. Among SNP positive cases and controls, 5 cases (8.7%) and no controls were heterozygosis for the occurrence of SNP. Genetic polymorphism in relation to the intronic region of the Calm-1 gene was studied by DNA extraction, polymerase chain reaction and restriction fragment length polymorphism method.