In a breakthrough, scientists have identified 11 new risk genes involved in the deadly Alzheimer's disease in a largest of its kind study.
The highly collaborative effort involved scanning the DNA of over 74,000 volunteers - the largest genetic analysis yet conducted in Alzheimer's research - to discover new genetic risk factors linked to late-onset Alzheimer's disease, the most common form of the neurodegenerative disorder.
By confirming or suggesting new processes that may influence Alzheimer's disease development - such as inflammation and synaptic function - the findings point to possible targets for the development of drugs aimed directly at prevention or delaying disease progression.
The International Genomic Alzheimer's Project (IGAP) reported its findings in the journal Nature Genetics.
"Collaboration among researchers is key to discerning the
genetic factors contributing to the risk of developing Alzheimer's disease," said Richard J Hodes, director National Institute on Ageing (NIA).
Until 2009, only one gene variant, Apolipoprotein E-e4 (APOE-e4), had been identified as a known risk factor. Since then, prior this discovery, the list of known gene risk factors had grown to include other players - PICALM, CLU, CR1, BIN1, MS4A, CD2AP, EPHA1, ABCA7, SORL1 and TREM2.
IGAP's discovery of 11 new genes strengthens evidence about the involvement of certain pathways in the disease, such as the role of the SORL1 gene in the abnormal accumulation of amyloid protein in the brain, a hallmark of Alzheimer's disease, researchers said.
It also offers new gene risk factors that may influence several cell functions, to include the ability of microglial cells to respond to inflammation.
The researchers identified the new genes by analysing previously studied and newly collected DNA data from 74,076 older volunteers with Alzheimer's and those free of the disorder from 15 countries.
The new genes - HLA-DRB5/HLA0DRB1, PTK2B, SLC24A4-0RING3, DSG2, INPP5D, MEF2C, NME8, ZCWPW1, CELF1, FERMT2 and CASS4 - add to a growing list of gene variants associated with onset and progression of late-onset Alzheimer's.