Considerable phenotypic heterogeneity, evidence for multiple genetic risk mechanisms4 and incomplete penetrance have led to complexities in understanding the genetic basis of AD.5 There have been 31 risk loci identified for AD to date.4 Loss‐of‐function mutations in the gene encoding filaggrin (FLG) are the strongest and most significantly associated genetic variants for AD.6 The gene discussed is FLG; the disease is Alzheimer disease.