Early-onset osteoarthritis, Charcot-Marie-Tooth like neuropathy, autoimmune features, multiple arterial aneurysms and dissections: an unrecognized and life threatening condition.

BACKGROUND: Severe osteoarthritis and thoracic aortic aneurysms have recently been associated with mutations in the SMAD3 gene, but the full clinical spectrum is incompletely defined. METHODS: All SMAD3 gene mutation carriers coming to our centre and their families were investigated prospectively with a structured panel including standardized clinical workup, blood tests, total body computed tomography, joint X-rays. Electroneuromyography was performed in selected cases. RESULTS: Thirty-four SMAD3 gene mutation carriers coming to our centre were identified and 16 relatives were considered affected because of aortic surgery or sudden death (total 50 subjects). Aortic disease was present in 72%, complicated with aortic dissection, surgery or sudden death in 56% at a mean age of 45 years. Aneurysm or tortuosity of the neck arteries was present in 78%, other arteries were affected in 44%, including dissection of coronary artery. Overall, 95% of mutation carriers displayed either aortic or extra-aortic arterial disease. Acrocyanosis was also present in the majority of patients. Osteoarticular manifestations were recorded in all patients. Joint involvement could be severe requiring surgery in young patients, of unusual localization such as tarsus or shoulder, or mimicking crystalline arthropathy with fibrocartilage calcifications. Sixty eight percent of patients displayed neurological symptoms, and 9 suffered peripheral neuropathy. Electroneuromyography revealed an axonal motor and sensory neuropathy in 3 different families, very evocative of type II Charcot-Marie-Tooth (CMT2) disease, although none had mutations in the known CMT2 genes. Autoimmune features including Sjogren's disease, rheumatoid arthritis, Hashimoto's disease, or isolated autoantibodies- were found in 36% of patients. INTERPRETATION: SMAD3 gene mutations are associated with aortic dilatation and osteoarthritis, but also autoimmunity and peripheral neuropathy which mimics type II Charcot-Marie-Tooth.

TNF receptor-associated periodic syndrome (TRAPS): a new cause of joint destruction?

TNF receptor-associated periodic syndrome (TRAPS) is a highly polymorphic autoinflammatory syndrome related to mutations in the TNFRSF1A gene encoding the type 1 TNF receptor. Arthralgia and nonerosive synovitis are among the most common manifestations. We report the case of a 73-year-old woman who presented with chronic erosive joint disease that progressed by flare-ups. Moderate nonspecific abdominal and cutaneous abnormalities were noted, suggesting TRAPS. This diagnosis was confirmed when genetic tests identified the R92Q mutation in the TNFRSF1A gene. Although glucocorticoid therapy was effective in alleviating the symptoms, combination therapy with methotrexate and etanercept neither decreased the frequency of the flare-ups nor slowed the pace of joint destruction. Treatment with anakinra is being considered. To our knowledge, this is the first reported case of joint destruction related to TRAPS. In patients with refractory inflammatory joint disease, the presence of extraarticular manifestations, however mundane, should suggest TRAPS.