Being born without ITPR2 may sound like a blessing: The gene regulates sweat production, and having none of it eliminates one's ability to sweat. Swedish researchers identified the rare genetic mutation after zeroing in on five children in one Pakistani family who are unable to sweat. What's particularly unusual in the children's case is that the disorder, known as anhidrosis, isn't accompanied by any other skin disorders. But as Popular Science reports, the condition is effectively a curse: In lacking the ability to sweat, the children can't regulate their body temperature. They live their days in the home's cellar, away from the heat that could render them unconscious, or even kill them.
The researchers determined that ITPR2 encodes the protein InsP3R2, as they explain in their study, published last week in the Journal of Clinical Investigation. Because the children don't have that protein, calcium ions aren't released from cells, reports LiveScience; without that release, the events that trigger sweating aren't themselves triggered. The finding actually has implications for the 2% of people who sweat too much, a more common disorder known as hyperhidrosis. Popular Science notes the condition can lead sufferers to take measures as extreme as wearing a layer of plastic between their skin and clothing. Adjusting InsP3R2 protein levels, perhaps via a drug, may be a more palatable treatment than what is currently typically used: Botox injections. Inhibiting the protein's production, says one researcher, "can reduce peripheral sweating by 60%." (Click to read about five siblings who must walk on all fours.)