A study in Belgium and the US has discovered a genetic cause for excessive sweating using mice and patient samples, which can reduce the stigma around the condition and potentially support the development of treatments. 

Excessive sweating is estimated to affect two to five per cent of the population and has been associated with malfunction of sweat glands. Many patients suffer from stigma, social isolation and depression, yet the condition has been neglected. 

Researchers from the EARA member Free University Brussels (VUB), Belgium, in collaboration with the Johns Hopkins University School of Medicine, US, sequenced the genes of more than 180 US patients with a hereditary form of the condition. They found mutations in the gene of a protein called Nav1.8 ion channel, involved in the regulation of electrical signals in the nervous system. 

To understand the mechanism behind it, the researchers turned to mice. Mice sweat only from their paws, so the team developed a new experiment to count the microscopic drops of sweat in the paws. They found that mice genetically altered to carry a mutation in the same protein also exhibited excessive sweating. Injecting medications already in use for other conditions that block nerve signals reduced excessive sweating in both male and female mice, opening up avenues for drug repurposing. 

“Some cases may be driven by the sweat glands themselves, while others appear to originate in the nervous system. Understanding those differences is critical if we’re going to develop more effective treatments,” said Malcolm Brock, researcher at John Hopkins and co-leader of the study published in Science Advances.