OSTM1 and osteopetrosis: The disease is characterized by a complex molecularpathogenesis caused by mutations in 23 genes (see theTable) responsible for the development of correspondingclinical osteopetrosis conditions (TCIRG1, CLCN7,OSTM1, PLEKHM1,SNX10, TNFSF11 (RANKL),TNFRSF11A(RANK ), IKBKG (NEMO), RAG1, RAG2,TRAF6, FERMT3,LRRK1, MITF, C16orf57, CSF1R, CAII,SLC29A3, CalDAG-GEF1, CTSK, WTX, LEMD3, RELA).