With 11,884 twin pairs, this study demonstrates that heritability for AD is as high as 79 percent, emphasizing the importance of genetic factors in the etiology of AD.

View all comments by Paul Coleman

This is an important paper on the largest population-based twin study on dementia to date. Its results suggest that the heritability of AD is likely represented by the upper end of previously reported estimates (possibly approaching 80 percent), emphasizing the need to intensify gene-finding efforts. If correct, the results of this study also imply that environmental (or non-genetic) factors play a much lesser, but still important, role in contributing to disease risk or variation in age of onset. Of particular interest: the authors conclude that most if not all of the increased prevalence of AD in women may be due to their greater longevity when compared to men.

View all comments by Lars Bertram