Five Genes That May Play A Role In Lewy Body Dementia

In a study led by National Institutes of Health (NIH) researchers, scientists found that five genes may play a critical role in determining whether a person will suffer from Lewy body dementia. Lewy body dementia is a disease caused by abnormal deposits of a protein. These protein deposits affect chemicals in the brain which lead to problems with thinking, movement, behavior, and mood.

“Lewy body dementia is a devastating brain disorder for which we have no effective treatments. Patients often appear to suffer the worst of both Alzheimer’s and Parkinson’s diseases. Our results support the idea that this may be because Lewy body dementia is caused by a spectrum of problems that can be seen in both disorders,†said Sonja Scholz, M.D., Ph.D., investigator at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and the senior author of the study. “We hope that these results will act as a blueprint for understanding the disease and developing new treatments.â€

The study was led by Dr. Scholz’s team and researchers in the lab of Bryan J. Traynor, M.D., Ph.D., senior investigator at the NIH’s National Institute on Aging. Evidence shows that genetics may play a role in the disorder- some of these rare cases can be caused by mutations in the gene for alpha-synuclein (SNCA). SNCA is the main protein found in Lewy bodies. Additionally, variants in the gene for apolipoprotein E (APOE) may also cause one to develop Lewy body dementia.

To understand more about the genetic forces behind Lewy body dementia, scientists compared the chromosomal DNA sequences of 2,981 Lewy body dementia patients with those of 4,931 healthy participants. Samples were collected from participants of European ancestry at 44 sites: 17 in Europe and 27 across North America. Results from the study concluded that sequences of five genes from the Lewy body dementia patients were often different from those of the control group. These genes include: BIN1, TMEM175, SNCA, APOE, GBA.

To help with this effort, the team published the genome sequence data from the study on the database of Genotypes and Phenotypes (dbGaP), a National Library of Medicine website that researchers can freely search for new insights into the causes of Lewy body dementia and other disorders.