Osteogenesis imperfecta and rheumatoid arthritis: is there a link?

Summary We present the cases of a mother and daughter with osteogenesis imperfecta, also diagnosed later with rheumatoid arthritis. In our patients finding and treating the over-imposed arthritis improved the joint pain initially attributed to osteogenesis imperfecta. Exploring joint inflammation in this setting could help ease the disease burden. Purpose Osteogenesis imperfecta (OI) is a rare hereditary disease evolving with recurrent fractures upon minor trauma, blue sclerae, and hearing loss. Although inflammation was not generally considered a feature of the disease, systemic inflammation was recently reported in children with OI and in murine models of OI. Method We present the cases of a mother and a daughter with OI, without a personal or family history of autoimmune diseases, who were also diagnosed with rheumatoid arthritis seropositive for anti-cyclic citrullinated peptide autoantibodies and rheumatoid factor. Results The genetic tests identified in both patients a deletion in COL1A1 gene (c.3399del, p.Ala1134Profs*105), not previously reported, not present in population databases, creating a premature translational stop signal in the COL1A1 gene in the collagen I major ligand binding region 3. In our patients finding and treating the over-imposed arthritis improved the joint pain initially attributed to OI. Possible pathogenic links between OI and RA are discussed. Conclusion The prevalence of joint inflammation in OI is unknown and may be underestimated. As musculoskeletal involvement affects the quality of life in most OI patients, exploring this relation may help ease the disease burden.