Abstract
OBJECTIVE: To investigate the frequencies of the apolipoprotein E (APOE) alleles and genotypes and study their relationship with the lipid profile in Jordanian patients with late-onset Alzheimer`s disease (AD). METHODS: This case-control study was carried out on 71 Jordanian individuals: 38 patients with late-onset AD (age >/=65 years) and 33 age-matched healthy controls. All participants were recruited from senior homes and Jordan University Hospital, Amman, Jordan between January 2010 and December 2013. Each sample was examined for APOE`s 3 major isoforms (e2, e3, e4) using the polymerase chain reaction technique (PCR) followed by the sequencing technique. In addition, samples were screened for lipid profiles (total cholesterol (TC), high-density lipoprotein (HDL), lower-density lipoprotein (LDL), and triglyceride (TG) levels. RESULTS: The e3/e4 genotype and e4 allele prevalence were higher in AD patients compared to healthy controls (26.3% vs. 3.0%, p=0.03 and 15.8% vs. 4.5%, p=0.03; respectively). In the AD group, the e2 carriers showed the lowest levels of total and LDL cholesterol, and the e4 carriers showed the highest levels of total and LDL cholesterol, although the difference was not statistically significant (p>0.05). CONCLUSION: APOE-e4 frequency was almost 4 times higher in the AD group compared to the control group, and this difference was statistically significant. A trend that was observed in the AD group regarding the lipid profile and e2 and e4 carriers requires further investigation using a larger sample size.