If you've ever had athlete's foot, you've had a fungal infection. Such infections are common and easily cleared up with over-the-counter anti-fungal drugs. But in rare cases, such usually harmless fungal infections can get beneath the skin and spread to the bones, gut, immune system and even the brain, causing a condition called deep dermatophytosis which can be fatal.
Writing in the New England Journal of Medicine, scientists at The Rockefeller University in the US and Necker Medical School in Paris have now discovered a gene fault that allows the fungus to spread in this way. To find the faulty gene, called CARD9, the researchers looked at DNA from 17 people who had succumbed to deep dermatophytosis but were otherwise healthy, with normal functioning immune systems. Previous research had suggested CARD9 might be the suspect, and the scientists found it was faulty in all 17 of the patients.
The scientists think their finding explains why fungal infections sometimes spread into the body, and why they can be so hard to treat when they do. In the case of families that carry the gene fault, this could lead to genetic testing, as well as prevention advice and targeted treatments. And it also lends weight to the idea that genetic variations between people make the difference between some people being able to shrug off minor infections while others fall seriously ill.