Link between genes and oral herpes susceptibility discovered

While the common cold and overexposure to sunlight are suspected triggers of oral herpes outbreaks, genetic factors may be at play as well. Researchers at the University of Utah School of Medicine recently discovered a region of the human chromosome linked to more frequent outbreaks of oral herpes. Results of their research were published in the February 1 issue of the Journal of Infectious Diseases.

The study began with the objective of identifying human genes linked to herpes simplex labialis, or oral herpes. Researchers performed serological testing on 421 volunteers from 39 families enrolled in the Utah Genetic Reference Project, a genomic study of multigenerational Utah families. Study participants who tested positive for HSV-1 were asked to record details on any outbreaks of oral herpes, including past episodes, promdromal symptoms and triggers. Based upon the information reported, participants were classified as either “frequently affected,” “mildly affected,” or “unaffected,” as determined by the number of annual outbreaks.

Once the participants were categorized, researchers conducted a genetic analysis on only those in the “frequently affected” (2 or more outbreaks a year) and “unaffected” (never reported an outbreak) groups, to make the distinction between the groups as clear as possible. Those that were in the “mildly affected” group, or were uncategorized, were excluded from the analysis. The analysis identified a region on human chromosome number 21 that contains genes that may be linked to increased susceptibility to oral herpes outbreaks.

The discovery of this genetic link could lead to a better understand of HSV infection and the factors that influence the frequency and severity of infection. As study author John D. Kriesel, MD, noted, “One or more of these genes might make excellent targets for new drugs to reduce the number of herpes outbreaks.” Implications for future research aren’t necessarily limited to oral herpes. According to Kriesel, “Finding a drug target to reduce the frequency of cold sores would be even more valuable if we could expand our study results to include genital herpes or herpes keratitis, and that’s something I’d like to do.”