The present study provides insight into the nature of the contribution of common genetic variation to AD risk. The most important implication of this study is that the estimated chip-heritability can account for about half of the broad-sense heritability of AD. Interestingly, a recent study [29] reported the chip-heritability of AD to be 21%, based on 7,188 Caucasian participants. This evidence suggests that about half of the “missing” heritability is not actually missing but jointly accounted for by small or moderate effects of common variants.
