Human autosomal recessive osteopetrosis maps to 11q13, a position predicted by comparative mapping of the murine osteosclerosis (oc) mutation.

Autosomal recessive osteopetrosis is a rare congenital disorder characterized by the development of abnormally dense bones, acrocephaly, severe anemia, hepatosplenomegaly and progressive deafness and blindness. The clinical course is rapidly progressive and is lethal at a very young age in the absence of a bone marrow transplant. The failure to remodel developing bone that is the basis of the disease process is most likely due to a dysfunction of the bone resorptive cell, the osteoclast. This phenotype is similar to that of the murine mutation osteosclerosis (oc), which is localized to proximal mouse chromosome 19. Given the similarity between the human and murine phenotypes, we tested whether human osteopetrosis maps to a region of conserved synteny. Microsatellite markers in the region of 11q12-13 were found to be linked to osteopetrosis in two consanguineous Bedouin kindreds. Recombination events were used to define the disease interval to an approximately 14 cM region between D11S1983 and D11S2371. A maximum LOD score of 7. 94 was obtained with D11S449 at straight theta = 0.