Using data from the Longitudinal Aging Study in India-Diagnostic Assessment of Dementia (LASI-DAD) and the Health and Retirement Study (HRS), we analyzed 4 biomarkers—the ratio of Amyloid beta 42-40 (Aβ42/Aβ40), Glial Fibrillary Acidic Protein (GFAP), Neurofilament Light Chain (NfL), and Phosphorylated Tau at Threonine 181 (pTau181)—in relation to cognitive outcomes. The gene discussed is MAPT; the disease is dementia.