Mutation Contributes to Faster Progression of Alzheimer’s Disease, Study Reports

A mutation in the BDNF gene can accelerate loss of memory and cognitive function in people at risk of developing Alzheimer’s, according to a study.

The study, “BDNF Val66Met predicts cognitive decline in the Wisconsin Registry for Alzheimer’s Prevention,” was published in the journal Neurology.

BDNF is an important neurotransmitter in the brain, playing a role in both neuron signaling and survival. The mutation of the gene is known as the BDNF Val66Met allele, or simply the Met allele.

“We found that people with Alzheimer’s risk who have this BDNF gene mutation called the Met allele may have a more rapid decline of memory and thinking skills,” Dr. Ozioma Okonkwo, the  author of the study, said in a news release. “Because this gene can be detected before the symptoms of Alzheimer’s start, and because this presymptomatic phase is thought to be a critical period for treatments that could delay or prevent the disease, it could be a great target for early treatments.”

Researchers wanted to see how many of the 1,023 people enrolled in the Wisconsin Registry for Alzheimer’s Prevention had the Met allele. The mean age of the enrollees was 55.

The team tested the patients’ memory and cognitive skills. They also tested 140 for beta-amyloid protein aggregates in the brain, a hallmark of Alzheimer’s disease.

Thirty-two patients carried the Met allele, researchers discovered. Their memory and cognitive function declined faster than those without the mutation, according to tests the team conducted.

Patients with both the Met allele and beta-amyloid accumulation experienced even greater memory and cognitive decline.

The results suggest that the Met allele plays an important role in cognitive decline and could become a target for therapies that prevent or slow the development of Alzheimer’s.

“When there is no mutation, it is possible the BDNF gene and the protein it produces are better able to be protective, thereby preserving memory and thinking skills,” Okonkwo said. “This is especially interesting because previous studies have shown that exercise can increase levels of BDNF. It is critical for future studies to further investigate the role that the BDNF gene and protein have in beta-amyloid accumulation in the brain.”