Researchers used blood samples to detect changes linked to Alzheimer’s disease

A group of researchers at the University of Turku uncovered changes in blood samples correlated with Alzheimer’s disease following a comprehensive study of disease-discordant Finnish twins. The findings were released in Clinical Epigenetics.

As part of an international study, researchers examined the blood samples of 23 Finnish twin pairs for any changes in epigenetic marks sensitive to changes in environmental factors, correlated with the neurodegenerative disease. They used the latest genome-wide methods and uncovered differences in multiple genomic regions.

According to researchers, the epigenetic marks uncovered in multiple different genomic regions were accomplished by measuring methylation levels in the DNA isolated from the blood samples of the twin pairs.

“Comparison of 23 disease discordant Finnish twin pairs with reduced representation bisulfite sequencing revealed peripheral blood DNA methylation differences in 11 genomic regions,” according to Mikko Konki, co-author of the study.

“The DNA methylation mark in ADARB2 gene was found to be differentially methylated also in the anterior hippocampus, including entorhinal cortex, of non-twin cases and controls.”

“Targeted bisulfite pyrosequencing of the DNA methylation mark in ADARB2 gene in 62 Finnish and Swedish twin pairs revealed that, in addition to the disease status, DNA methylation of this region is influenced by gender, age, zygosity, APOE genotype, and smoking,” the findings detailed.

“Further analysis of 120 Swedish twin pairs indicated that this specific DNA methylation mark is not predictive for Alzheimer’s disease and becomes differentially methylated after disease onset.”

Although the findings concluded that DNA methylation differences could be identified in the blood samples of twins pairs discordant for the neurodegenerative disease, more research is needed to validate the diagnostic value of the marker panels.

“Further studies are needed to elucidate the potential importance of the associated genes in neuronal functions and to validate the prognostic or diagnostic value of the individual marks or marker panels,” the study’s co-authors concluded.