PON1 has been implicated in the etiology of a number of adult-onset neurologic diseases such as Parkinson and Alzheimer diseases (Erlich et al. 2006; Leduc and Poirier 2008; Paragh et al. 2002; Zintzaras and Hadjigeorgiou 2004). Here, PON1 is linked to early-onset autosomal dominant Alzheimer disease.