Sweating is necessary for maintaining bodily temperature. The body is generally capable of taking care of itself but sometimes gene problems crop up, throwing processes out of whack. According to a study carried out by a team of international researchers, a gene is responsible for blocking sweat production, leading to a condition known as anhidrosis.
It's called ITPR2 and it works by controlling basic cellular processes in sweat glands. Calcium is necessary in sweat production, the release of which is dictated by ITPR2. Without the gene, sweat production would not be possible.
Published in the Journal of Clinical Investigation, the study was led by RIKEN Brain Science Institute's molecular cell biologist Katsuhiko Mikoshiba and Uppsala University's Niklas Dahl, a genetics expert.
Dahl's work is focused on studying single-gene diseases called Mendelian disorders. By identifying the genes responsible for these diseases, Dahl aims to develop treatment and diagnostic tools that will help in dealing with Mendelian disorders.
For this study, a family from Pakistan was identified as having several children suffering from anhidrosis. Since the children don't sweat, they spend their days cooped up in the cellar of their homes to prevent heatstroke.
There are several possible causes associated with anhidrosis and the condition normally forms alongside other diseases but the Pakistani children were all well. Save for their inability to sweat, they didn't have any other conditions that may have contributed to the development of their anhidrosis.
Dahl then took to analyzing the children's genomes and his study revealed the gene mutation ITPR2. It was after discovering ITPR2 that he sought to collaborate with Mikoshiba, who was responsible for discovering the IP3 receptor type 2 or IP3R2, a protein encoded by ITPR2 that facilitates calcium release and ultimately sweat production.
"This is the first report of IP3 receptor type 2 mutation in human disease. The surprise was that a point mutation, not a large deletion was enough to cause the human disorder," said Mikoshiba.
Anhidrosis is a relatively rare condition but its opposite, hyperhidrosis, which involves excessive sweating, is more common, affecting about two percent of the population. Dahl said that symptoms associated with hyperhidrosis may be alleviated using drugs that inhibit the functions of IP3R2. However, the protein is present in many other tissues so disrupting its functions may lead to other problems. Further evaluation is needed before IP3R2 drugs can be considered as hyperhidrosis treatment.
The study was supported by the Swedish Research Council, Swedish Links, Asia, the Uppsala University Hospital, the Uppsala University Science for Life laboratory, The Moritani Scholarship Foundation, the Swedish Society for Medical Research, and the Grants-in-Aid for Scientific Research.
