Late-onset Alzheimer's Disease Susceptibility Gene

Alzheimer's disease is the most common cause of dementia in the elderly. It is characterized clinically by a gradual onset and progression of memory loss, and by the postmortem presence of two types of neuropathological inclusions: neurofibrillary tangles and senile plaques. Late-onset Alzheimer's disease (LOAD) is a complicated disease, associated with several factors. There is now overwhelming evidence that the z4 allele of apolipoprotein gene is a major risk factor for LOAD. However, the APOE locus only accounts for a proportion of the overall genetic risk for AD. There are additional genetic and environmental factors that are involved in this form of disease. It is not clear about the etiology and pathogenesis of Alzheimer's disease. We conducted the research in 68 LOAD patients with 157 controls in Chinese population in order to get some susceptible genes of LOAD in Chinese.In the present study, blood samples of 225 unrelated Han Chinese individuals from Guangxi province were collected randomly and genomic DNA was extracted. Polymorphism analyses in apolipoprotein, Angiotensin Converting Enzyme, Endothelial Nitric Oxide Synthase, Interleukine 1, Aldehyde Dehydrogenase and Ferritin 65 genes were executed with AFLP or RFLP method.Statistical analyses were conducted and many significant results were obtained. The data strongly support a significant association between the APOE s4 allele and ACE I allele, especially in homozygotes, and late-onset Alzheimer's disease. APOE and ACE genes are risk factor for late-onset Alzheimer's disease. There are no association between IL-1a, NOS3, ALDH2. FE65 and LOAD. The results also suggest that APOE and NOS3 genotypes may be dependent risk factors for LOAD, but fail to find an interaction between the ACE, IL-la, ALDH2, FE65 genes and APOE gene. According to the difference of thirteen alleles of six genes in different samples, we classified 225 samples into 59 groups. No. 1 and No. 4 combinations are two risk combinations for LOAD, but No. 36 combination is not.