How climate change may impact some genetic diseases, including certain types of epilepsy

As climate change results in more frequent and intense heat waves, new research at the Epilepsy Society suggests that rising temperatures could have unexpected effects on human health — particularly for people with certain rare genetic conditions including some epilepsies.

Scientists have discovered that small genetic differences may make certain individuals more sensitive to extreme temperatures. In these cases, heat or cold does not just cause discomfort but may worsen disease symptoms or even trigger them for the first time.

Neurological conditions are increasingly recognised as being particularly sensitive to climate-related stressors such as heat exposure and extreme weather events.
 

The research, led by Sanjay Sisodiya, Director of Transformation at the charity and Professor of Neurology at UCL, looked at what they call “calortypic variants.” These are specific gene changes that can affect how proteins in the body function at different temperatures. 
 

Many proteins in our bodies function very close to their physical limits. They may  only be stable and work properly within a narrow temperature range. Even a small change in temperature can interfere with how well they function.
 

Impact on underlying conditions

Using large collections of genetic data from people with rare diseases, our researchers were able to identify individuals who carry these temperature-sensitive gene variants. Further analysis showed that changes in temperature could influence how certain genes behave, potentially aggravating underlying conditions.
 

Significantly, researchers found that in some cases, a person may have a genetic condition is mild or goes unnoticed under normal conditions. But during periods of extreme heat, symptoms might worsen or become more noticeable.
 

The findings raise concerns about “hidden vulnerabilities” in a warming world. As global temperatures continue to rise, people who were previously unaware of any temperature-related health risks may become more affected.
 

Variants that increase vulnerability 

Professor Sisodiya explained: “We all carry a variety of different types of genetic variants. Most of the time, these variants do not cause us problems. Sometimes, a genetic variant might be the cause of someone's epilepsy, and we have been doing research on this topic for some years. 
 

“More recently, we also wondered whether some genetic variants that any of us might carry, while not causing us any problems most of the time, might make us more vulnerable to hot weather, especially heatwaves. An analogy might be a muscle injury that only bothers us when we exert ourselves, but goes unnoticed during everyday activities. 
 

“Our study shows that there are such genetic variants, and in some individuals these variants might lead to difficulties during heatwaves. We are extending this work to try to better understand how many people might have such variants, and hope to use this information to provide better safety advice around heatwaves.”
 

Research could aid prediction

The researchers hope that identifying temperature-sensitive genetic variants will help doctors better predict which patients might be most at risk during extreme weather events. This knowledge could help shape medical care, public health planning, and strategies to protect the most vulnerable as the planet warms.
 

Professor Sisodiya continued: “Our study highlights an important and often overlooked link between climate change and human genetics. While climate change is widely recognised for its environmental and economic impacts, its interaction with our biology may also play a significant role in future health challenges.”

Further reading

Genetic susceptibility to heat identifies rare neurological diseases at particular risk from climate change impacts
Genetic risk in a warming world