by HealthDay News:

Insight into genes that play a key role in disrupting immune system pathways in the brains of people with Alzheimer’s disease could offer a potential target for new drugs against the disease, two new studies show.

“Defining the precise steps of the inflammatory response crucial to causing Alzheimer’s disease has been elusive. We are pleased to discover these novel insights into that process,” Bin Zhang, lead author of one of the studies and an associate professor of genetics and genomic sciences at the Icahn School of Medicine at Mount Sinai in New York City, said in a school news release.

In the study, Zhang’s team analyzed brain tissue samples from deceased Alzheimer’s patients, as well as healthy people who had died. By measuring the activity level of thousands of genes in these tissue samples, the team identified which gene networks are disrupted in diseased brains.

by News Wise:

Scientists at UCLA have discovered a new genetic risk factor for Alzheimer’s disease by screening people’s DNA and then using an advanced type of scan to visualize their brains’ connections.

Alzheimer’s disease, the most common cause of dementia in the elderly, erodes these connections, which we rely on to support thinking, emotion and memory. With no known cure for the disease, the 20 million Alzheimer’s sufferers worldwide lack an effective treatment. And we are all at risk: Our chance of developing Alzheimer’s doubles every five years after age 65.

The UCLA researchers discovered a common abnormality in our genetic code that increases the risk of Alzheimer’s. To find the gene, they used a new imaging method that screens the brain’s connections — the wiring, or circuitry, that communicates information. Switching off such Alzheimer’s risk genes (nine of them have been implicated over the last 20 years) could stop the disorder in its tracks or delay its onset by many years.

by Marilynn Marchione for KDFW Fox 4:

Scientists have identified a new gene variant that seems to strongly raise the risk for Alzheimer’s disease, giving a fresh target for research into treatments for the mind-robbing disorder.

The problem gene is not common – less than 1 percent of people are thought to have it – but it roughly triples the chances of developing Alzheimer’s compared to people with the normal version of the gene. It also seems to harm memory and thinking in older people without dementia.

The main reason scientists are excited by the discovery is what this gene does, and how that might reveal what causes Alzheimer’s and ways to prevent it. The gene helps the immune system control inflammation in the brain and clear junk such as the sticky deposits that are the hallmark of the disease. Mutations in the gene may impair these tasks, so treatments to restore the gene’s function and quell inflammation may help.

by HealthDay News:

If you live long enough, a potentially harmful gene linked to Alzheimer’s disease may lose its punch, according to a new study.

The ApoE4 gene is linked to the risk of developing Alzheimer’s, heart disease and diabetes. This study found that the gene becomes less important once people reach their 90s.

Mayo Clinic researchers looked at 121 people, ages 90 to 99, in Olmsted County, Minn., who were living on their own in or long-term care facilities. The participants completed an interview, had a physical exam and filled out a quality-of-life questionnaire. Blood samples were taken for genetic analysis.

People with the ApoE4 gene were no worse off than those without the gene, the investigators found.

by Kanoko Matsuyama for Businessweek:

People with plaques in the brain associated with Alzheimer’s disease may have a greater risk for cognitive impairment than those who have a gene tied to the dementia-causing illness, Australian researchers found.

In a study of 141 healthy subjects, those with clumps of amyloid beta plaques in their brains at the start of the study had as much as a 20 percent greater decline in memory and thinking over an 18-month period than those with fewer plaques. The research also showed that patients with the gene linked to Alzheimer’s, called ApoE4, had a greater mental decline, though having the gene didn’t alter the decline related to the plaques.

by Senior Care Corner:

Alzheimer’s disease is a scary diagnosis, both for the patient and their loved ones. There is almost no one in America who is currently unaffected by this disease either with a loved one, friend or possibly themselves.

What if you were told you have the “gene” for Alzheimer’s? Would you want to be tested or even know if you might be in the early stages? A recent article that we found extremely fascinating explored these specific questions and gave a glimpse into the world of a family in the grips of Alzheimer’s disease.

A Family Afflicted by Alzheimer’s

At a family reunion there were gathered 14 siblings ranging in age from 29 to 52 years. Included in the family photo were cousins, aunts and uncles in addition to the siblings. One observer remembers that many of the siblings did not “seem right.” They appeared confused, stared into space and found difficulty keeping up with the conversations that day.

by Medical XPress:

A study by scientists at the University of Southampton has revealed new clues to why people who carry the Alzheimer’s risk gene APOE4 may be more likely to develop the disease.

The findings, which link the risk gene to clearance of the hallmark Alzheimer’s protein amyloid, take scientists a step further towards understanding the devastating disease.

The research, published on July 25 in the journal PLoS ONE, was funded by Alzheimer’s Research UK.

The APOE gene is the biggest known genetic risk factor for late-onset Alzheimer’s disease. People who carry the APOE4 version of the gene have a higher risk of developing the disease at an earlier age than people who carry APOE3 or APOE2. However, the reason for this increased risk has remained unclear.

by EurekAlert:

A team led by investigators at the Stanford University School of Medicine has found that the most common genetic risk factor for Alzheimer’s disease disrupts brain function in healthy older women but has little impact on brain function in healthy, older men.

Women harboring the gene variant, known to be a potent risk factor for Alzheimer’s disease, show brain changes characteristic of the neurodegenerative disorder that can be observed before any outward symptoms manifest.

Both men and women who inherit two copies (one from each parent) of this gene variant, known as ApoE4, are at extremely high risk for Alzheimer’s. But the double-barreled ApoE4 combination is uncommon, affecting only about 2 percent of the population, whereas about 15 percent of people carry a single copy of this version of the gene.

by Michael Smith for MedPage Today

Even in cognitively healthy adults, too much of the protein linked to Alzheimer’s disease appears to affect some aspects of cognition, researchers reported.

In a cross-sectional analysis of adults ages 30 through 89, the protein beta-amyloid increased with age, and higher levels were associated with deterioration of some cognitive functions, according to Kristen Rodrigue, PhD, of the University of Texas Dallas, and colleagues.

And about one in five of those over 60 had markedly elevated deposition of the protein based on PET imaging for beta-amyloid, with a corresponding decline in some functions, Rodrigue and colleagues reported online and in the Feb. 7 issue of Neurology.

by Nicole Ostrow for Bloomberg Businessweek

People who are genetically susceptible to developing Alzheimer’s disease may be able to reduce their risk with exercise, a study found.

Carriers of the Alzheimer’s gene APOE-4 who regularly exercised over a decade were five to 10 times less likely to have brain plaques linked to the disease than those with the gene who weren’t physically active, said John C. Morris, senior author of the study published today in Archives of Neurology.

About 5.4 million Americans have Alzheimer’s and, by 2050, that number is expected to grow to as many as 16 million, according to the Alzheimer’s Association. Between 15 and 20 percent of the general population carry the APOE-4 gene, Morris said. While the study shows that those who exercised had fewer amyloid plaques in the brain, the signature markers of the disease, more follow up is needed to see if exercise actually delayed or blocked symptoms, he said.