Over 40 previously unknown genes discovered for Alzheimer's disease

Washington: An additional 42 genes connected to the development of Alzheimer's disease have been uncovered in the largest study of genetic risk for Alzheimer's to date.

"This is a landmark study in the field of Alzheimer's research and is the culmination of 30 years' work," study co-author Julie Williams, center director at the UK Dementia Research Institute at Cardiff University, said in a statement.

"Lifestyle factors such as smoking, exercise and diet influence our development of Alzheimer's, and acting to address these now is a positive way of reducing risk ourselves," she added. "However, 60-80% of disease risk is based on our genetics and therefore we must continue to seek out the biological causes and develop much-needed treatments for the millions of people affected worldwide."

The previously unknown genes point to additional pathways for disease progression besides the well-known APOE e4 gene or the development of amyloid beta and tau, two hallmark proteins that build up in the brain with devastating results as Alzheimer's progresses.

A number of the newly discovered genes focus on very detailed reactions between proteins in the body that govern how inflammation and the immune system might damage brain cells, the study found.

The discovery will provide scientists with potential new targets for treatments, medications and lifestyle changes that might reduce the risk of the deadly brain disease, experts say.

The global study analysed the genomes of 111,326 people with clinically diagnosed Alzheimer's and compared those with genes from 677,663 cognitively healthy people.

The study identified 75 genes that are linked to an increased risk of Alzheimer's, 33 of which were already known. It also confirmed years of research into the roles of amyloid beta and tau.

Of the 42 new genes found to be connected to Alzheimer's, many clustered into several suspected but unconfirmed pathways for disease development. One such pathway is the body's immune system, designed to protect us from germ invaders.

According to the study, involves genes associated with inflammation. The body uses inflammation as a defense mechanism to kill off pathogens, but it also plays a role in removing damaged cells.

Additional complicated gene interactions were found by the study, all of which illustrate that the disease is made up of different pathologies and it progresses differently in each person who gets Alzheimer, the CNN news reported.