Apolipoprotein E (APOE) Allele Frequencies and Genotypic Distribution in Huambo, Angola

Background/Objectives: Non-communicable diseases (NCDs) are a leading cause of death globally, particularly in low- and middle-income countries undergoing rapid epidemiological transition. Apolipoprotein E (APOE) polymorphisms have been implicated in modulating risk for cardiovascular and neurodegenerative diseases. This study characterizes the distribution of APOE alleles and genotypes in an Angolan population sample and explores associations with demographic variables. Methods: A cross-sectional study was conducted in Huambo Province, Angola, with 200 unrelated adults aged 40-70 years. Genotyping for ε2, ε3, and ε4 was performed via real-time PCR. Allelic and genotypic frequencies were calculated and tested for Hardy-Weinberg equilibrium. Associations with sex, age (≤54 vs. >54 years), and urban vs. rural residence were analyzed. Results: ε3 was the most frequent allele (63%), followed by ε4 (24.8%) and ε2 (12.2%). The ε3 homozygous genotype was prevalent (44%), with ε3/ε4 (19%) and ε2/ε3 (18%) also common. Significant Hardy-Weinberg disequilibrium was observed due to excess ε4 homozygotes and deficit of certain heterozygotes; possible contributing factors, including population structuring, convenience sampling, and technical aspects of genotyping, are discussed. ε4 prevalence was higher in urban residents and older individuals, while ε3 and ε2 were more common in rural areas and younger participants. Conclusions: Our results reveal notable genetic heterogeneity and highlight the epidemiological and evolutionary importance of ε4 in Angola. The findings underscore the need for integrating population genomics into public health strategies targeting NCD prevention, especially in rapidly urbanizing African contexts.