OSTEOPETR

OSTEOPETR is a coordinated project that brought together world-class scientistis expert in a genetic bone disease called osteopetrosis. Osteopetrosis is characterised by sclerosis of the skeleton, reduced or complete lack of osteoclast function and, as a consequence, impaired bone resorption. Various modes of inheritance and degrees of severity are known. The disease can be lethal in infancy and has no fully efficacious cure. OSTEOPETR identified new genes responsible of the pathogenesis of previously unrecognised forms of osteopetrosis. It also established the correlation beteween the mutant genes and the clinical outcome of some forms. These two achievements have important implications for therapy because they allowed to recognize patients that cannot benefit from bone marrow transplantation, the only therapy that so far can partially resolve the disease. OSTEOPETR also understood the pathophysiology of defective tooth eruption and tooth movement, which are important complications affecting the quality of life of patients. Importantly, OSTEOPETR experimented some new therapies in pre-clinical models of the disease, for instance establishing the feasibility of RNAi therapy for autosomal dominant forms, and innovative cell and pharmacological therapies for the autosomal recessive forms. From a clinical perspective, OSTEOPETR has set up patient surveillance criteria and a professional registry with complete osteological analysis of patients affected by severe forms. This coordinated project has involved leader groups from three participating Countries and has provided new insights into diagnosis and experimental therapies that have an important impact on patients. We expect the knowledge generated by this project to be translated in the next future into benefits for patients.