CogniFit's Science blog: Neuroscience Study Finds Link To Early And Late Onset Alzheimer’s Disease

Neuroscience Study Finds Link To Early And Late Onset Alzheimer’s Disease

Neuroscience is a complex field that is constantly developing and identifying new data and information. A recent study suggests the same gene mutations may be linked to inherited, early-onset Alzheimer’s disease. And it has been found in people with a more common late-onset form of the same illness.

The discovery was made by researchers at Washington University School of Medicine in St. Louis. And while it is in the preliminary stage, it may lead doctors to what they have long been searching for; a change in the way Alzheimer’s disease is classified.

Doctors are beginning to dispose of the idea that early-onset Alzheimer’s is inherited and late-onset is sporadic. The reason for this is because sporadic cases and familiar clustering occurs in both age groups. As a result, they now view it as both early and late-onset diseases sometimes having the same causes.

The neuroscience study suggests that the disease mechanism can be the same regardless of when the Alzheimer’s disease appears. Of course, those who get the disease at a younger age has more risk factors and fewer protective ones and those who develop later in life have more protective factors. However, the mechanism may be the same for each.

Researchers have begun using next-generation DNA sequencing to analyze genes that are linked to dementia. After sequencing the amyloid precursor protein gene and the PSEN1 and PSEN2 genes, mutations were identifiable as causes of early-onset Alzheimer’s disease. The findings suggested an increase in rare variants in the Alzheimer’s genes in families that had four or more members where affected with late-onset disease.

In addition, the study also found mutations in the MAPT and GRN genes in some Alzheimer’s patients. This shows that patients may have been incorrectly diagnosed with Alzheimer’s disease when in fact it was frontotemporal dementia.

The first scientist to identify a mutation in the APP gene linked to inherited, early-onset Alzheimer’s disease is now looking at families with multiple cases of Alzheimer’s. However, the scientist is focusing on those who have no mutations in previously identified genes. Her interpretation is that they carry mutations in genes that scientists have yet to find.

The goal is to find out whether new sequencing techniques could speed the discovery of these genes or not. And she believes a study like this is more than possible today unlike just a few years ago. Another scientist says it is now possible to sequence all of the genes at the same time.

Technology has continually advanced making more neuroscience studies possible today than ever before. And with these capabilities, new findings suggest it is worthwhile to sequence these genes in people with a strong family history of Alzheimer’s disease. And scientists now no longer look at early- and late-onset disease as being different illnesses.