APOE Genotyping in Cognitive Disorders: Preliminary Observations from the Greek Population

Area of Science:

• Neuroscience
• Genetics
• Biomarkers

Background:

• Alzheimer's disease (AD) is the leading cause of cognitive decline.
• The apolipoprotein E (APOE) gene, with alleles ε2, ε3, and ε4, is a key genetic risk factor for AD.
• The APOE ε4/ε4 genotype is increasingly recognized for its potential to indicate a distinct genetic subtype of AD.

Purpose of the Study:

• To examine the influence of APOE ε4 homozygosity and heterozygosity on Alzheimer's disease biomarker profiles.
• To investigate the role of APOE ε4 in cognitive disorders within the Greek population.
• To assess the predictive value of APOE ε4 for Alzheimer's disease diagnosis.

Main Methods:

• Recruited 274 patients with cognitive disorders from the Greek population.
• Performed APOE genotyping to determine ε2, ε3, and ε4 allele status.
• Analyzed cerebrospinal fluid (CSF) for Alzheimer's disease biomarker profiles.

Main Results:

• The presence of the APOE ε4 allele correlated with an earlier age of symptom onset.
• APOE ε4 was associated with reduced amyloid biomarkers, regardless of AD or non-AD profiles.
• APOE ε4 positivity demonstrated a near 100% positive predictive value for an AD biomarker profile.

Conclusions:

• The APOE ε4 allele significantly influences cognitive impairment and Alzheimer's disease risk and clinical characteristics in the Greek population.
• The APOE ε4/ε4 genotype is a strong indicator for the presence or co-existence of Alzheimer's disease in cognitively impaired individuals.
• Genetic profiling via APOE genotyping can aid in the diagnosis of Alzheimer's disease.