However, FD is an X-linked disease and, overall, female patients with FD show a milder phenotype, later onset of symptoms, and slower disease progression.38 In addition, GLA−/− male mice consistently recapitulate the classical FD phenotype (total enzyme absence) manifested only by male patients,13 whereas female GLA−/− mice do not represent the clinical situation in women. Here, GLA is linked to X-linked disease.