[Genomic approaches to bone and joint diseases. Mutations of RANK, OPG and RANKL genes found in humans].

Molecular mechanisms of osteoclast formation and activation have been clarified since the discovery of osteoprotegerin (OPG). When receptor activator of NF-kappaB ligands (RANKL) and macrophage colony stimulating factors (M-CSF) bind their receptors RANK and c-fms, respectively, osteoclast precursor cells differentiate into osteoclasts. OPG interferes with the interactions between RANK and RANKL, and inhibits osteoclast formation and function. There is no doubt that RANK, RANKL and OPG are key molecules in osteoclast differentiation and activation in physiological and pathological conditions. This review summarizes mutations of RANK, OPG, RANKL genes found in humans.