New genes identified that link to Alzheimer's

The largest analysis of DNA from patients has uncovered another 11 genes that are linked to dementia, which could help to identify the cause of Alzheimer's disease. A total of 21 genes have now been identified that are linked to the pathway of Alzheimer's, which could lead to the identification of further genetic risk factors in terms of the late onset disease type.

A group of international researchers performed DNA scanning of more than 74,000 volunteers, which is the largest sample to ever have been used for such a study. The research was performed by the International Genomic Alzheimer's Project (IGAP), with funding from components of the National Institutes of Health and the National Institute on Aging (NIA). 

Teams were formed within four consortia throughout the US and Europe. The aim was to detect variants within genes that are involved in the development of Alzheimer's disease and to see how they might affect the onset and progression of the illness.

Alzheimer's geneticists from around 145 institutions were involved in the research, which found that there were versions of 21 genes that increased an individual's chance of developing the disease. While having these genes does not guarantee that the disease will develop, it does lead to an increased chance.

DNA from 74,076 older volunteers was used for the study, some of whom had the disease and others that didn't, from 15 different countries. The 11 new genes that were identified, increased the evidence that certain pathways allow the disease to develop and speed its progression, such as the SORL1 gene being related to the build-up amyloid protein on the brain.

Doctor Gerard Schellenberg, from the University of Pennsylvania School of Medicine, Philadelphia, said: "Interestingly, we found that several of these newly identified genes are implicated in a number of pathways. Alzheimer's is a complex disorder, and more study is needed to determine the relative role each of these genetic factors may play. I look forward to our continued collaboration to find out more about these - and perhaps other - genes."