Apolipoprotein E polymorphisms in adults over 60 years of age with mild cognitive impairment and Alzheimer's disease in different Venezuelan populations

Introduction: Alzheimer's disease represents a serious public health problem that tends to worsen over time. Among the most important genetic predisposing factors is the presence of the epsilon 4 allele of the apoprotein E gene (APOE). Objective: To determine the allelic and genotypic frequencies of the APOE isoforms in adults over 60 years old, with mild cognitive impairment and Alzheimer in Greater Caracas, and in the indigenous Pemon community of the Kamarata-Kanaimo area, Bolivar State. Materials and methods: 267 patients were studied: 96 controls, 40 mild cognitive impairment, 108 Alzheimer from Caracas and 23 from Kamarata-Kanaimo. APOE isoforms were determined with the AP1210Z: Seeplex (R) ApoE Genotyping kit. Results: epsilon 4 showed a significant association with mild cognitive impairment (OR = 5.03 95% CI 0.98-25.70) and EA (OR = 5.78 95% CI 1.24-26.85). The genotype frequencies of the control and mild cognitive impairment groups were: epsilon 3/epsilon 3> epsilon 3/epsilon 4> epsilon 2/epsilon 4> epsilon 3/epsilon 2> epsilon 4/epsilon 4; in Alzheimer: epsilon 3/epsilon 3> epsilon 3/epsilon 4> epsilon 4/epsilon 4> epsilon 2/epsilon 4> epsilon 3/epsilon 2. In Kamarata-Kanaimo the order was epsilon 3/epsilon 3> epsilon 3/epsilon 4> epsilon 4/epsilon 4, the allele epsilon 2 was not found. Conclusions: The allelic and genotypic frequencies of APOE in our sample have a similar distribution to other studies done in Venezuela and the Americas. The absence of the epsilon 2 allele in the indigenous community of Kamarata-Kanaimo warrants further investigation. The positive association of the epsilon 4 allele with both Alzheimer and mild cognitive impairment is reinforced. Early determination of the epsilon 4 allele carriers can help establish preventive measures in our population.