SLC29A3 and osteopetrosis: A rare form of osteopetrosis with low osteoclast content,called dysosteosclerosis, accompanied by red-purplemacular atrophy, platyspondylitis, and metaphyseal osteosclerosis,is caused by mutations in the SLC29A3 gene(member 3 of the 29 solute carrier family), which codes fora highly expressed lysosomal nucleoside carrier in myeloidcells.