| Inheritance | Co-dominant (alongside APOE3 or APOE4) |
| Gene | APOE (Apolipoprotein E) |
| Chromosome | 19q13.32 |
| SNP ID | rs429358 (Cys130), rs7412 (Cys176) |
| Allele Frequency | ~8-12% in Caucasian populations; ~5-10% globally |
| Nucleotide Changes | T→C at rs429358 (Cys130), T→C at rs7412 (Cys176) |
| Reduced lipid binding capacity | approximately 30-40% of APOE3 |
| Reduced AD Risk | APOE2 carriers have approximately **40-50% reduced risk** of developing AD compared to APOE3 homozygotes [3] |
| Later Age of Onset | When AD develops, APOE2 carriers often have a later age of onset (approximately 2-3 years later than APOE3) |
| Reduced Amyloid Burden | PET imaging studies show 30-50% lower amyloid plaque burden in APOE2 carriers |
| Slower Progression | When disease is established, progression may be slower |
| Databases | OMIMOrphanetClinicalTrialsPubMed |