MAFB and multicentric carpo-tarsal osteolysis with or without nephropathy: MAFB Thr62Arg and several other amino acid exchanges at this position cause Multicentric Carpotarsal Osteolysis Syndrome (MCTO, OMIM #166300) [21,32], and Thr62Arg in c-MAF results in the Ayme-Gripp syndrome (OMIM #601088) [24] (Figure 6b).