September 19, 2017
In a first-of-its-kind study, researchers at 23andMe found a link between the susceptibility for some of the most common infectious diseases and dozens of specific variants in genes involved in the body’s frontline immune response system.
Published today in the journal Nature Communication, the research is unique in that, up until now, very few genome-wide association studies (GWAS) have looked specifically at common and non-life threatening infectious diseases. Most have focused on more serious maladies such as HIV, hepatitis, and malaria.
“While these are not as serious as HIV or malaria, they are the most common infections suffered by people and they have a profound impact on human health,” said lead author Chao Tian, Ph.D., a Senior Statistical Geneticist at 23andMe.
For this study, Chao and a team of researchers at 23andMe looked at data from more than 200,000 23andMe customers who consented to participate in research and who completed surveys on their health history. By looking at their history of infections and infection-associated procedures, as well as running GWAS on those conditions, the researchers were able to identify relationships between host genes and common infections.
The conditions that they found associations for include chickenpox, shingles, cold sores, mononucleosis, mumps, hepatitis B, strep throat, pneumonia, yeast infections, urinary tract infections, tonsillectomy and childhood ear infections, to name a few.
In all, more than 50 genetic variants were found that were associated with 23 common infectious diseases. The study also revealed important roles of specific amino acid mutations at the antigen-binding site of human leukocyte antigen (HLA) genes, the hundreds of genes on chromosome 6 that regulate the body’s immune system.
Each individual’s HLA response is expressed slightly differently as it discerns whether something is an invading pathogen, like a virus or bacteria. That difference can have an impact on an individual’s susceptibility to infectious diseases. The study found that the associations map to different HLA regions depending on whether the infectious disease is caused by a virus, as with shingles, or if it was induced from bacteria, as with pneumonia.
Previous research has found associations between HLA systems and some individual diseases, such as a study published in May by researchers at Vanderbilt University Medical Center (VUMC) and the University of Arizona College of Pharmacy.
Utilizing electronic health records and genetic information from about 28,000 people, this study found associations between HLA regions and certain autoimmune diseases such as type 1 diabetes and rheumatoid arthritis. However, there have been very few studies of this type, and this new research from 23andMe is the first to look at common infections.
Read the full paper in Nature Communications here.