Association analysis of HTR6 and HTR2A polymorphisms in sporadic Alzheimer's disease

In order to identify gene variants related to the serotonergic neurotransmi tter system that possibly represent a hereditary risk factor for sporadic A lzheimer's disease (AD), patients suffering from AD and nondemented psychia tric inpatients without symptoms of dementia were genotyped for polymorphis ms of HTR6 (267C/T) and HTR2A (- 1438G/A). Although there was a tendency to ward an increased number of the genotype TT of the 5-HT6 receptor polymorph ism in AD patients when compared to controls (2.8% vs. 1.3%), neither this nor the 5-HT2A promoter polymorphism showed significant differences in thei r genotypic or allelic. distribution among patients and controls. These pol ymorphisms probably do not represent major genetic risk factors of AD. Howe ver, further studies including, other genetic variants of the serotonergic neurotransmitter system are needed in order to elucidate their role in AD.