APOE and APOC1 gene polymorphisms are associated with cognitive impairment progression in Chinese patients with late-onset Alzheimer＇s disease

Current evidence shows that apolipoprotein E （APOE）, apolipoprotein CI （APOC1） and low density lipoprotein receptor-related protein （LRP） variations are related to late-onset Alzheimer＇s disease. However, it remains unclear if genetic polymorphisms in these genes are associated with cognitive decline in late-onset Alzheimer＇s disease patients. We performed a 30-month longitudi- nal cohort study to investigate the relationship between Alzheimer＇s disease and APOE, APOC1, and LRP. In this study, 78 Chinese Han patients with late-onset Alzheimer＇s disease were recruit- ed form Guangxi Zhuang Autonomous Region in China. APOE, APOC1, and LRP genotyping was performed using polymerase chain reaction-restriction fragment length polymorphisms. The Mini-Mental State Examination and Clinical Dementia Rating Scale were used to assess pa- tients＇ cognitive function. After a 30-month follow-up period, we found a significant reduction in Mini-Mental State Examination total score, a higher proportion of patients fulfilling cognitive impairment progression criteria, and a higher proportion of APOC1 H2 carriers in APOE 4 carriers compared with non-carriers. In addition, the APOE 4 allele frequency was significantly higher in the cognitive impairment progression group compared with the non-cognitive im- pairment progression group. In conclusion, APOE e4 plays an important role in augmenting cognitive decline, and APOC1 H2 may act synergistically with APOE ~4 in increasing the risk of cognitive decline in Chinese patients with late-onset Alzheimer＇s disease.