One in five people have been found to have a gene that protects against Alzheimer's and Parkinson's diseases
A variant of an immune-related gene has been linked to a reduced risk of developing Alzheimer's and Parkinson's diseases in a diverse population of people.A new study of diverse ethnic groups has found that about 20-30% of people carry versions of an immune-related gene that may protect against Alzheimer's and Parkinson's diseases. They studied a huge collection of full-genome data from 176,000 people of European, Asian, Hispanic and African-American descent. These people had one of these neurodegenerative diseases, and their genetics were compared to those of people without these diseases.
It turned out that people who carry a version of the human leukocyte antigen (HLA) gene known as HLA-DRB1*04, or DR4 for short, have an 8-15% lower risk of developing these neurodegenerative diseases. In addition, it is found in one in five people.
Moreover, these people had fewer abnormally folded brain proteins such as tau clumps , which are hallmarks of these pathologies. This hints that gene variants may protect against these diseases by preventing the accumulation of these proteins.
The shape-shifting HLA proteins underlie the adaptive immune system, which tailors the body's response to pathogens such as viruses. In a smaller previous study, study co-author Dr. Emmanuel Mignot, a neuroimmunologist and professor at Stanford University, found - certain variants of the HLA-DRB1 gene, which encodes the HLA protein, are associated with a reduced risk of both Alzheimer's and Parkinson's disease.
The findings, published Aug. 29 in the journal PNAS, may have implications for the development of new vaccines against Alzheimer's and Parkinson's diseases.