Mutational analysis of PRNP in Alzheimer's disease and frontotemporal dementia in China.

The prion protein (PRNP) gene is associated with prion diseases, whereas variants of the PRNP gene may also explain some cases of Alzheimer disease (AD) and frontotemporal dementia (FTD) in Caucasian populations. To determine the prevalence of the PRNP gene in patients with AD and FTD in China, we screened all exons of the PRNP gene in a cohort of 683 cases (606 AD and 77 FTD) in the Chinese Han population and we detected a novel missense mutation p.S17G in a late-onset AD (LOAD) patient. Furthermore, we analyzed the PRNP M/V polymorphism at codon 129, which was previously reported as a risk factor. However, there were no significant differences in genotype and allele frequency either in AD (OR = 0.75[0.378-1.49], P = 0.492), or FTD patients (OR = 2.046[0.265-15.783], P = 0.707). To our knowledge, this is the first study to reveal a correlation between the PRNP gene and Chinese AD and FTD patients in a large cohort. This study reports a novel p.S17G mutation in a clinically diagnosed LOAD patient, suggesting that the PRNP mutation is present in Chinese AD patients, whereas, M129V polymorphism is not a risk factor for AD or FTD in the Chinese Han population.