Study finds Alzheimer’s disease gene already makes its mark in childhood

Children with the ε2ε4 genotype have 5 percent smaller hippocampus, an area of the brain area that plays a role in memory.

A study published today in Neurology has found that a gene that is associated with the development of Alzheimer’s disease effects the brain, including thinking skills, as early as in childhood. 1,187 children and young adults aged three to 20 years were included in the study, given brain scans and genetic tests and examined on their thinking and memory skills. The lead author, Linda Chang, explains the next steps in this research and why she hopes her study will help in the development of preventative measures to stop the onset of the disease.

ResearchGate: Could you explain the significance of the findings from your study on the link between a certain gene and Alzheimer’s disease?

Linda Chang: We studied children with genotypes that are more common in people with Alzheimer's disease to discover if this already has an impact in childhood. These children show slightly delayed brain development and cognitive function during early ages, before the ages of eight-10 years. Therefore, these findings indicate that these genes not only influence the development of Alzheimer's disease later in life, but can also affect early brain development.

RG: What impacts does this gene have on brain development?

Chang: Younger children with the genotypes that are more common in individuals with Alzheimer's disease had slower brain development in brain regions often affected in patients with Alzheimer's.

RG: What ethical considerations do researchers or medical professionals have to take into account when children are found to be a positive match for the ε4 gene?

Chang: We should not be checking for these genotypes in any children until we have established methods to improve their brain function or to prevent the development of Alzheimer's disease later in life. Studies such as this one are to provide a better understanding on how these genes might influence brain development and later brain aging. Also, it is important to emphasize that the older children with these genotypes showed normal brain structure and function.

RG: What could the findings of your study mean for potential preventative measures to stop the disease from occurring?

Chang: The findings of this study might provide early indications of who might benefit from preventive measures when they become available. These individuals might also want to avoid activities that might lead to traumatic brain injury, such as contact sports.

RG: What other factors aside from genetics contribute to the onset of Alzheimer’s disease?

Chang: Many other genes and factors have been shown to increase the risk for Alzheimer's disease. Other factors include age – risks increase risk with older age – and diet and lifestyle, for example people who are physically active have a lower risk of developing Alzheimer’s disease. These factors are thought to be responsible for the decreased incidence of dementia in the U.S. and Europe.

RG: What are the next steps in this research?

Chang: Follow-up longitudinal studies are needed to evaluate whether the findings in the current cross-sectional study are valid. Also, since the rarer genotype groups had fewer children, we would like to replicate this study in a larger cohort of children.

Image credit Neil Conway