A significant breakthrough in genetic research has identified a specific variant in a gene responsible for iron regulation that appears to significantly increase the risk of dementia in men. The study, which analyzed data from a massive cohort of healthy older individuals, found that men who carry two copies of a common genetic variant are twice as likely to develop dementia during their lifetime compared to women with the same genetic profile. These findings, published in the prestigious medical journal Neurology, offer new insights into the complex intersection of genetics, gender, and neurodegenerative disease, potentially opening doors for more personalized approaches to prevention and treatment.
The research focused on the haemochromatosis (HFE) gene, a critical component of the body’s internal machinery for regulating iron levels. While the HFE gene is well-known in clinical circles for its role in iron overload disorders, its specific relationship with cognitive decline and dementia has remained a subject of intense investigation. By utilizing data from the landmark ASPirin in Reducing Events in the Elderly (ASPREE) trial, researchers were able to look closely at how variations in this gene influence long-term brain health in a large, diverse population of aging adults.
According to the study’s findings, a specific variant of the HFE gene known as H63D is remarkably common in the general population. Professor John Olynyk, a co-author of the study from the Curtin Medical School, noted that the prevalence of this variant is higher than many might expect. Approximately one in three individuals carries a single copy of the H63D variant. In most cases, carrying just one copy does not appear to have a measurable impact on a person’s overall health or their likelihood of developing dementia. However, the risk profile changes dramatically for those who inherit two copies of the variant—one from each parent.
For the one in 36 people who carry two copies of the H63D variant, the research revealed a stark gender disparity. While women carrying two copies did not show a significantly increased risk of cognitive decline, men with the same genetic makeup faced more than double the risk of developing dementia. This discovery underscores the importance of sex-specific research in understanding neurodegenerative conditions, as the same genetic marker can manifest in vastly different ways depending on the biological context of the individual.
The biological mechanisms behind this increased risk remain a point of active inquiry. Professor Olynyk explained that while the genetic variant itself is a fixed part of an individual’s DNA and cannot be altered, the physiological pathways it influences could be targets for future medical intervention. The HFE gene is primarily responsible for managing how the body absorbs and stores iron, but the researchers found a surprising twist in the data. Despite the gene’s primary function, the study found no direct correlation between the levels of iron in the blood and the increased risk of dementia in the affected men.
