Home > Medical > Genetics > News 17 September 2013 Cold sores linked to a gene mutation Scientists have finally discovered why some people are prone to cold sores while others are not. 0 Shutterstock Related Cold sores Check Assess your diabetes risk » Quiz Am I at risk for COPD? » Ask CyberDoc » 10 ways to boost your metabolism World's Most Famous TB Patients Why some people are troubled by cold sores while others are not has finally been explained by scientists.Cold sores affect around one in five people but, until now, no one has been sure why some are more prone to the virus that causes them.Researchers at the University of Edinburgh have found that people affected by cold sores have a mutation in a gene, which means their immune system is not able to prevent them from developing. Cold sores are caused by a strain of the herpes simplex virus herpes simplex virus type 1 (HSV-1). Between 80 and 90% of people are infected with the virus, but only about a quarter of them get frequent cold sores.Scientists analysed thousands of genes to identify which ones expressed the proteins needed by the body's immune system to prevent the virus from becoming active and – as a result – cold sores from developing.Inadequate immune responseThey then looked at blood samples from people with cold sores and found that one of the genes previously identified – IL28b – was mutated. This genetic mutation means that the body is not able to mount an adequate immune response to the virus, which results in cold sores.The gene identified is also linked to treatment responses for hepatitis C patients. If this gene is mutated, patients are less likely to respond as well to treatment. The link is further evidence that a single genetic mutation can be linked to different viruses.The study, published in the journal Plos Pathogens, was funded by the Medical Research Council, the Biotechnology and Biological Sciences Research Council, the Wellcome Trust and the European Union.Professor Juergen Haas, of the University of Edinburgh's Division of Pathway Medicine, said: "Most people carry the cold sore strain of the herpes simplex virus, but until now we never knew why only some of them develop cold sores. "Knowing that susceptibility to the virus involved relates to people's genes reinforces the need to research, not only the evolution of viruses themselves, but also the susceptibility of hosts to infection." (Picture: cold sore from Shutterstock) EurekAlert More in Medical Chimpanzee victim's immune system rejects face transplant More: GeneticsNews advertisement Read Health24’s Comments Policy Comment on this story 0 comments Comments have been closed for this article. Logout Comment 0 characters remaining Share on Facebook Loading comments... Other news Medical A story of hope: HIV positive graduates inspire others Lifestyle SA set to join global plain cigarette packaging trend Medical Families to fight mental health patients' transfer Medical Female cancer survivors need more fertility info Medical New procedure for severely enlarged prostate Medical End of polio in sight as Nigeria celebrates one year polio-free From our sponsors Cipla Nutrition- Dummies Guide to Enduro Prep 4 clever ways to stay active this winter Key signs you need a change in diet Clear your head with fast-acting, long-lasting Sinutab® Nasal Spray Live healthier PMS, depression & suicide » Don't let PMS get you down Symptoms of PMS Diagnosing PMS The link between PMS, depression and suicidal thoughts The symptoms of premenstrual dysphoric disorder (PMDD) are similar to those of PMS, but generally more severe – and could include depression and even thoughts of suicide. A vegan marathon runner » Comrades: don't run if you're ill Fuel your body for the Comrades Running the Comrades Marathon on a vegan diet Donovan Will, who is training to run the Comrades Marathon, speaks to Health24 about his plant based diet and fears of getting injured ahead of the big race.