JAMA logoAlzheimer’s is known to be the most common form of dementia. Experts share that previously studied genetic variants are linked with the growth and progression of Alzheimer’s disease. This was identified by examining the relation between genetic loci related to Alzheimer’s disease and neuroimaging measures related to the risk associated with the disease. Experts have seemingly labeled new genetic risk factors for further analysis.

The mechanism of Alzheimer’s remains unsolved but double studies have revealed that the disease is 60 percent to 80 percent ancestral. Recent findings have shown that one genetic variant known as APOE, was shown to manipulate the disease risk and age in the beginning. Three additional loci that cause the risk of Alzheimer’s have been identified with the help of new findings from genome-wide association studies. Neuroimaging measures that include the volume of hippocampus, amygdala and other brain structures are linked with the risk and development of Alzheimer’s disease.

The authors reveal that “The demonstration that recently discovered genetic risk factors for Alzheimer’s disease also influence these neuroimaging traits would provide important confirmation of a role for these genetic variants and suggest mechanisms through which they might be acting,”

Alessandro Biffi, M.D., and Christopher D. Anderson, M.D., of Massachusetts General Hospital, Boston, and Broad Institute, Cambridge, Mass., and colleagues examined relations between genes and neuroimaging results. This study included 168 individuals with possible Alzheimer’s disease, 357 with mild mental impairment and 215 who were stable mentally.

The four loci formerly linked with the disease were evaluated including six neuroimaging traits that are associated with the disease. It was observed that APOE gene was linked with both clinical Alzheimer’s disease and with all the neuroimaging traits except one. It was also identified that other candidate genes exhibited collective effect on the analyzed neuroimaging measures.

“Our results indicate that APOE and other previously validated loci for Alzheimer’s disease affect clinical diagnosis of Alzheimer’s disease and neuroimaging measures associated with disease,” the authors write. “These findings suggest that sequence variants that modulate Alzheimer’s disease risk in recent genome-wide association studies may act through their influence on neuroimaging measures.”

The genetic analysis of neuroimaging traits revealed two new target gene locations namely BIN1 and CNTN5 which had greater relation with Alzheimer’s disease. The authors reveal that their findings for these loci are preliminary but they may help increase the need for future genetic studies and genome-wide association studies for the disease. These findings highlight their relation with neuroimaging correlates Alzheimer’s and its status. Recent meta-analysis revealed the association between the B1N1 gene location and the disease.

This study was reported in the June issue of Archives of Neurology, one of the JAMA/Archives journals.