Study finds common gene variant that doubles dementia risk for men

Australian researchers have identified a common genetic variant that doubles the risk of dementia in men. The team from Curtin University said that one in three people carry one copy of the variant, known as H63D, while one in 36 carry two copies. The research, published in the journal Neurology, found that men who carry a double H63D variant are twice as likely to develop dementia in their lifetime compared to women. The study, based on 19,114 healthy older people in Australia and the US, investigated whether people who had variants in the hemochromatosis (HFE) gene, which is critical for regulating iron levels in the body, might be at increased risk of dementia. “Having just one copy of this gene variant does not impact someone’s health or increase their risk of dementia. However, having two copies of the variant more than doubled the risk of dementia in men, but not women,” said Professor John Olynyk, from the Curtin Medical School. While the genetic variant itself cannot be changed, the brain pathways which it affects — leading to the damage that causes dementia — could potentially be treated if we understood more about it,” Olynyk added. Professor Olynyk said further research was needed to investigate why this genetic variant increased the risk of dementia for males but not females. “The HFE gene is routinely tested for in most Western countries, including Australia, when assessing people for hemochromatosis — a disorder that causes the body to absorb too much iron. Our findings suggest that perhaps this testing could be offered to men more broadly,” Olynyk said. While the HFE gene is critical for controlling iron levels in the body, the team found no direct link between iron levels in the blood and increased dementia risk in affected men. “This points to other mechanisms at play, possibly involving the increased risk of brain injury from inflammation and cell damage in the body,” Olynyk said.