Association between polymorphisms in transforming growth factor-β1 and sporadic Alzheimer's disease in a Chinese population
Alzheimer's disease (AD) is the most common neurodegenerative disorder of the brain. It causes the slow progressive loss of cognitive functions that ultimately leads to dementia and death in the elderly. The etiology and mechanism of late-onset AD (LOAD) are poorly understood, and genetic factors might play an important role in the development of AD. The aim of this study was to investigate the association between common polymorphisms in TGF-β1 with LOAD in a Chinese Han population. Two single nucleotide polymorphisms in TGF-β1 (rs1800469 and rs1982073) were genotyped in 202 patients with sporadic LOAD and 225 control subjects using polymerase chain reaction restriction fragment length polymorphism. Our results showed that rs1800469 in TGF-β1 were significantly associated with LOAD. The frequencies of the AC genotypes of rs1800469 were significantly higher in the LOAD patients than in the control subjects (42.5% vs 28.6%; P = 0.001). The minor allele (C) frequency was significantly higher in patients with LOAD than in control subjects (30.7% vs. 21.0%; P = 0.001). The genotypes and allele of rs1982073 in TGF-β1 were also significantly associated with LOAD. The frequency of the TG genotype of rs1982073 was significantly higher in the LOAD patients than in the control subjects (38.1% vs. 27.1%; P = 0.013). The minor allele (G) frequency was significantly higher in patients with LOAD than in control subjects (22.2% vs. 16.7%; P = 0.032). These results suggest that common variants in TGF-β1 might contribute to the development of LOAD in the Chinese population.