These claims are inconsistent with (1) the absence of AMBN expressed sequence tags (EST) from bone in the human (Hs.272396; 0/71618) and mouse (Mm.8437; 0/34066) EST databases, (2) Ambn pseudogenization in mammals that continue to make bone but not enamel, and (3) the absence of reported bone phenotypes in persons with amelogenesis imperfecta (AI) caused by biallelic AMBN defects. Here, AMBN is linked to amelogenesis imperfecta.