An Analysis In The Relationship Between The Polymorphism Of ABCA1Gene Exon R1587K And The Serum Lipid Level As Well As The Susceptibility Of Alzheimer’s Disease

[OBJECTIVE] To study the gene polymorphism relationship of the sporadic Alzheimer’s disease (SAD) and the ATP binding cassette transporter Al(ABCAl) of Han nationality in Hunan Province.[METHODS] In this paper, a case-control association study was used. From June2010to December2010, we randomly collected104cases with sporadic AD and104cases with non AD normal cognitive function as the control group simultaneously. The method, chain reaction restriction fragment length polymorphism (RFLP-PCR), was adopted to determine the gene polymorphism of ABCA1R1587K. SPSS17.0was used to carry on the statistical analysis.[RESULTS]1. Compared with the control group, the total serum cholesterol (TC) level of the AD group was significantly higher (P<0.05), the high-density-lipoprotein cholesterol level (HDL-C) was significantly lower (P<0.05), there wasn’t any significant difference in the triglyceride level (TG) and the low-density-lipoprotein cholesterol level (LDL-C)(P>0.05).2. Logistic regression analysis of single factor showed that the risk of AD in senile patients was2.68times higher than young patients, in patients with the hyperlipidemia history was2.24times higher than none- hyperlipidemia-history patients, in patients with high TC level was2.1times higher than patients low TC level, in patients with low HDL-C level was3..36times higher than patients with high HDL-C level.3. The allele and the genotype frequency of R5187K were both correspondent to Hardy-Weinberg detection (P>0.05). The distribution of the allele and the genotype frequency in two groups were significantly different (PO.05). The genotype frequency of RR, RK, KK in the AD group and the control group were58.65%,32.69%,8.66%and46.15%,44.23%,9.62%respectively. The genotype frequency of R, K were75.00%,25.00%and68.26%,31.73%. Stratified by sex, the distribution of three type of gene (RR、RK、KK) and the allele frequency (R、K) of female patients in the AD group had a statistically significant difference (χ2=5.158, P<0.05;χ2=5.357, P<.05), compared with the control group, and there was a difference of the locus gene and the genotype frequency in male R1587K. But the difference didn’t reach a statistically significant level (P>0.05).4. Based on genotype KK, the risk of AD increased1.68times in patients who exposed genotype RR,1.30times in RK. The risk of AD in allele R carriers was1.62times higher than allele K carriers.5. Disease incidence degree analysis showed that allele R in R1587K could increase the risk of AD (OR=2.615,95%CI:0.853-5.156, P=0.039). After further correction in parameters like gender, age, BMI, smoking history, alcohol history and various lipid parameters, there was still a correlation between R1587K and AD (OR=2.364,95%CI:0.837-5.421, P=0.041).6. In AD group, compared with genotype KK, the TC and LDL-C level in genotype RR+RK increased significantly, while HDL-C decreased significantly (p<0.05). Compared with the control group, the TC and LDL-C level of RR+RK carriers increased significantly, while HDL-C decreased significantly (P<0.05).[CONCLUSIONS]1. In Hunan Han nationality, the total cholesterol (TC) levels increased in the sporadic Alzheimer’s disease patients while the high density lipoprotein cholesterol (HDL-C) levels decreased.2. There was a probably certain correlation between the gene polymorphisms of ABCA1R1587K and the susceptibility of the sporadic AD. Genotype RR and allele R might increase the risk of AD as well.3.1587K alleles might produce a beneficial clinical lipid spectrum.