Osteoarthritis (OA) refers to a heterogeneous group of distinct diseases which express a common radiographic and clinical phenotype at diarthrodial joints.It is the leading cause of pain and disability in the elderly with a prevalence of 75 percent in the population aged 70 years. There is a substantial genetic component in the etiology of osteoarthritis. It is expected that genetic heterogeneity, the extent of which is unknown yet, contributes to a spectrum of osteoarthritis related phenotypes. Linkage as well as candidate gene studies are being performed to identify the genes involved.The overall aim of our research project is to identify genes that contribute to osteoarthritis. The aim of the present thesis was to understand the relation between hemochromatosis and osteoarthritis. As a part of this project, candidate osteoarthritis genes were analysed. These include the gene encoding the alpha domain of collagen type IX (COL9A1) and the HFE gene involved in hereditary hemochromatosis, a disorder that coincides with arthropathy. This thesis, therefore, brings together two related complex diseases, that share related phenotypes and possibly some of the underlying genetic components.