Could those with Alzheimer's Gene Show Symptoms in Childhood?

Statistics show that more than 5 million Americans are living with Alzheimer's and 1 in 3 seniors will die from it or another form of dementia.

As previous studies have shown that a gene known as SORL1 may play a role in increased risk for onset of the disease, a recent study suggests that some carrying the high-risk gene could begin showing brain changes as early as childhood, decades before the illness appears.

"We need to understand where, when and how these Alzheimer's risk genes affect the brain, by studying the biological pathways through which they work," said Dr. Aristotle Voineskos, head of the Kimel Family Translational Imaging-Genetics Laboratory at CAMH and lead study author, via a press release. "Through this knowledge, we begin to design interventions at the right time, for the right people."

To understand the dangers of the gene, researchers studied both those with and without Alzheimer's disease, in the hopes of identifying genetic differences in SORL1 via brain changes.

The first group of participants consisted of healthy individuals ages eight to 86. Researchers used diffusion tensor imaging (DTI) to study brain activity. They found that those with a specific copy of SORL1 showed a reduction in white matter connections in the brain that are essential for memory performance and function.

The second group consisted of those with post-mortem brain tissue from 189 individuals less than a year old to 92 years without the disease. Those with the same copy of the SORL1 gene showed brain tissue disruption in the process of gene translation.

The third and final set of participants involved in the study came from post-mortem brains of 710 individuals, aged 66 to 108, all of whom suffered from mild cognitive impairment or more cognitive functioning problems, such as Alzheimer's disease. This group showed an increased presence of amyloid-beta, a protein that's commonly found in Alzheimer's disease, with a connection to the SORL1 gene.

"The gene has a relatively small effect, but the changes are reliable, and may represent one 'hit,' among a pathway of hits required to develop Alzheimer's disease later in life," Voineskos adds, via the release.

However, researchers note that in order to develop genetic interventions involving the disease, other risk genes must first be analyzed, also.

More information regarding the study can be found via Molecular Psychiatry.