Presence of Alzheimer's Genes Influences Brain Imaging
Research also implicates two novel genes, CNTN5 and BIN1, as Alzheimer's disease loci
MONDAY, June 14 (HealthDay News) -- The presence of established Alzheimer's disease (AD) genes, and a pair of promising and novel AD genes, influence the brain characteristics seen in magnetic resonance imaging (MRI) studies of patients with the disease, according to a study in the June issue of the Archives of Neurology.
Alessandro Biffi, M.D., of the Massachusetts General Hospital in Boston, and colleagues recruited 168 subjects with probable AD, 357 subjects with mild cognitive impairment, and 215 subjects with normal cognition for whom apolipoprotein E (APOE) and genome-wide genetic data were available. The researchers assessed the influence of established AD loci and novel AD loci implicated in prior genome-wide association studies (GWASs) on MRI results, including hippocampal volume, amygdala volume, white matter lesion volume, entorhinal cortex thickness, parahippocampal gyrus thickness, and temporal pole cortex thickness.
The markers at the APOE locus were associated with all AD phenotypes seen on MRI with the exception of white matter lesion volume. The previously-validated AD variants at the CR1 and PICALM loci, and markers at two novel loci, BIN1 and CNTN5, were also associated with multiple AD characteristics seen on MRI.
"In summary, we have shown that established and candidate AD genes have a role in six neuroimaging traits linked to AD. Furthermore, two promising genes from prior AD GWASs, CNTN5 and BIN1, are also associated with these neuroimaging measures, which heightens their interest as novel AD loci. These genes may act selectively, influencing only one or a few established AD-related MRI measures. Future studies are required to replicate and expand these findings," the authors write.
The study was funded in part with contributions from a number of pharmaceutical companies.