PPARD and early-onset autosomal dominant Alzheimer disease: Variants of the rs8192678 PGC-1α polymorphism have previously been studied alongside polymorphisms in peroxisome proliferator-activated receptor delta (PPARD) and sirtuin 1 (SIRT1) in relation to Alzheimer's disease and were found not to be associated with AD in a Finnish case-control situation [50].