MAPT and argyrophilic grain disease: In 2008, a single case with AGDphenotype was linked to a novel S305I MAPT mutation and54 there is evidence from one series that theincidence of MAPT H1 is slightly higher in AD cases with AGD than in those withoutAGD.38 However, othergenetic studies have failed to discover a sustained link between AGD and aparticular gene locus.