[Multicentric carpotarsal osteolysis in a rheumatologist's practice].

Multicentric carpotarsal osteolysis (MCTO) syndrome is a rare skeletal dysplasia associated with missense mutation in the MAFB gene, usually manifesting in young childhood, and showing variative phenotypic signs and course. The clinical manifestations of the syndrome include aggressive osteolysis predominantly of carpal and tarsal bones, progressive nephropathy, and mild craniofacial anomalies. The similarity between the initial clinical manifestations of MCTO and the symptoms of childhood inflammatory joint diseases makes a diagnosis very difficult, in the early stages of the disease in particular, and frequently leads to the ungrounded use of long-term immunosuppressive therapy. The paper describes a familial case of MCTO without affecting the kidneys in the mother and daughter.