Of the 139 linear distances pairs that showed significant differences between Fgfr2+/S252W Apert syndrome mice and their unaffected littermates and the 61 linear distance pairs that showed significant differences between Fgfr2cC342Y/+ Crouzon syndrome mice and their unaffected littermates, only 10 of these pairs were common to the two comparisons, suggesting that neither mutation causes profound differences in brain-skull integration and that the changes that do occur are mutation-specific, testifying to the uniqueness of each craniofacial syndrome. This evidence concerns the gene FGFR2 and Apert syndrome.