FLG and Alzheimer disease: FLG loss-of-function mutations occur in 10% of Europeans, imparting an increased risk of AD, food allergy, and asthma.12,13 The overall increase in the risk of AD conferred by a single FLG loss-of-function mutation is approximately 3.3,14 with a significant additional and independent effect conferred by intragenic copy number variations in FLG. 15Importantly, FLG mutations increase the risk of developing asthma only in the presence of AD.13