Age-dependent association between the Q7R polymorphism in the Saitohin gene and sporadic Alzheimer's disease

A vigorous controversy exists over whether tau tangles or amyloid-beta plaques are the primary cause of neurodegeneration in Alzheimer's disease (AD), and it is not well established whether genetic variation in tau is associated with AD. A recently identified novel protein, named Saitohin (STH), shares tissue expression pattern with tau, and preliminary evidence in a North American population indicates that a polymorphism at codon 7 (Q7R) of the STH gene is a predisposing factor for sporadic AD. A case-control study utilizing a clinically well-defined group of 315 sporadic AD patients and 307 control subjects was performed to test this association. The current study reveals that increased risk of AD associated with the STH RR genotype (OR 2.17, p = 0.04) is limited to late-onset (after the age of 72 years) AD cases.