In 191 elderly T2D‐patients, four TCF7L2 SNPs (rs7901695, rs7903146, rs11196205, and rs12255372) were tested for association with volumes of white matter hyperintensities, gray matter, amygdala, and hippocampal imaging by using brain magnetic resonance. The gene discussed is TCF7L2; the disease is type 2 diabetes mellitus.