Osteopetrosis
Name OMIM Gene
OPTA1 607634 LRP5 receptor
OPTA2 166600 CLCN7 chloride channel
OPTB1 259700 TCIRG1 ATPase
OPTB2 259710 RANKL
OPTB3 259730 CA2 ( renal tubular acidosis )
OPTB4 611490 CLCN7 chloride channel
OPTB5 259720 OSTM1 ubiquitin ligase
OPTB6 611497 PLEKHM1 adapter protein
OPTB7 612301 TNFRSF11A ( RANK receptor )
Causes -- Gene variation
Osteopetrosis, literally stone bone, also known as marble bone disease or Albers-Schönberg disease, is an extremely rare inherited disorder whereby the bones harden, becoming denser, in contrast to more prevalent conditions like osteoporosis, in which the bones become less dense and more brittle, or osteomalacia, in which the bones soften. Osteopetrosis can cause bones to dissolve and break. It is one of the hereditary causes of osteosclerosis. It is considered to be the prototype of osteosclerosing dysplasias. The cause of the disease is understood to be malfunctioning osteoclasts and their inability to resorb bone. Although human osteopetrosis is a heterogeneous disorder encompassing different molecular lesions and a range of clinical features, all forms share a single pathogenic nexus in the osteoclast. The exact molecular defects or location of the mutations taking place are unknown. Osteopetrosis was first described in 1903, by German radiologist Albers-Schönberg.