Which genetic factor is the best established risk factor for late-onset sporadic Alzheimer's disease?
- A Apolipoprotein E epsilon 4 allele on chromosome 19 ✓
- B Amyloid precursor protein mutation on chromosome 21
- C Presenilin 1 mutation on chromosome 14
- D TREM2 mutation
Correct answer: A. Apolipoprotein E epsilon 4 allele on chromosome 19
Explanation
The apolipoprotein E epsilon 4 allele is the strongest common genetic risk factor for late-onset Alzheimer's disease, increasing risk in a dose-dependent fashion, whereas the epsilon 2 allele appears protective. Presenilin 1 and APP mutations cause autosomal dominant early-onset familial Alzheimer's disease, not the late-onset sporadic form asked about here. TREM2 variants confer modest risk but are far less established than APOE e4.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.