Definition:

Multicentric carpotarsal osteolysis syndrome (MCTO) is a rare skeletal dysplasia characterized by progressive bone resorption (osteolysis), predominantly (although not exclusively) of the carpal and tarsal bones. The early clinical appearance can mimic polyarticular juvenile idiopathic arthritis; however, subsequent clinical and radiographic appearances are characteristic. Clinical manifestations comprise aggressive osteolysis of the carpal and tarsal bones, an often progressive nephropathy leading to end-stage renal disease, craniofacial anomalies and mental impairment. Both simplex cases and families with autosomal-dominant inheritance have been reported. Recently, heterozygous missense mutations in the MAFB gene have been causally related to MCTO patients.