Conversely, genetically predicted increased expression of PGS1 (OR: 0.931; 95% CI: 0.868–0.998; p = 0.045), ETFA (OR: 0.965; 95% CI: 0.933–0.998; p = 0.038), and MRPL38 (OR: 0.927; 95% CI: 0.867–0.992; p = 0.029) was associated with reduced AD risk, suggesting protective effects through roles in cardiolipin synthesis, electron transfer, and mitochondrial ribosomal function in mitigating cognitive decline. This evidence concerns the gene PGS1 and Alzheimer disease.