These mutations are strongly associated with AD risk, particularly early‐onset and severe disease.6 Other, less prevalent, loss‐of‐function mutations in FLG have been identified.10, 11, 12 Despite increased understanding of the importance of genetic factors, the rising AD prevalence has been too substantial and rapid to be explained purely by genetic factors.13 Environmental factors have been implicated in the rising AD prevalence; exposure to such factors in utero or in later life may play a role in AD aetiology.14 The gene discussed is FLG; the disease is Alzheimer disease.