The disease seems to occur in one of two patterns ... But the pathognomonic feature of osteitis deformans must be seen on histology. It has been described as a tile-like or 'mosaic' pattern ...

Two of these candidate genes, CSF1 and TNFRSF11A (located at 1p13 and 18q21, respectively), code for proteins already known to be associated with Paget disease pathology and osteoclast function.