Alzheimer’s: Dr Chris discusses the early signs of condition
Dementia is a devastating condition that causes the ongoing decline of the brain. This can cause problems with memory loss, personality changes and even mobility. There are several different types of dementia, but Alzheimer’s disease is the most common.
It is thought to affect more than 55 million people across the world, and is among one of the leading causes of death. Despite this, no cure currently exists.
But a breakthrough discovery has offered fresh hope that this could one day be possible. Scientists have identified specific genetic variants linked with Alzheimer’s that they say could hold the key to eradicating the disease.
US researchers identified a total of 17 genetic variants that may influence the risk of people developing Alzheimer’s. They say the discovery could lead to treatment and prevention methods for the neurodegenerative disease.
The study, published in the Alzheimer’s Association’s journal Alzheimer’s and Dementia, enabled researchers to pinpoint rare and important genes and variants, building upon genome-wide association studies that focus solely on common variants and regions.
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A breakthrough discovery could help scientists find a cure for Alzheimer’s (Image: Getty Images)
Dr Anita DeStefano, a professor of biostatistics at Boston University School of Public Health (BUSPH) and a co-senior author of the study, explained: “Prior genome-wide association studies using common variants have identified regions of the genome, and sometimes genes, that are associated with Alzheimer’s disease.
“Whole genome sequence data interrogates every base pair in the human genome and can provide more information about which specific genetic change in a region may be contributing to Alzheimer’s disease risk or protection.”
As part of the research, the BUSPH team conducted single variant association analyses and rare variant aggregation association tests using whole genome sequencing data from the Alzheimer’s Disease Sequencing Project (ADSP).
The ADSP data included more than 95 million variants among 4,567 participants with or without the disease.
Alzheimer’s disease is thought to affect around 55 million people across the world (Image: Getty)
Among the 17 significant variants linked with Alzheimer’s disease, a variant called KAT8 was one of the most notable, as it was associated with the disease in both the single and rare variant analyses.
The researchers also found associations with several rare variants called TREM2 variants.
According to Dr Chloé Sarnowski, co-lead author of the study, their methods allowed the researchers to decipher whether associations were shared across different ethnographic populations.
“By using whole genome sequencing in a diverse sample, we were able to not only identify novel genetic variants associated with Alzheimer’s disease risk in known genetic regions, but also characterise whether the known and novel associations are shared across populations,” she said.
Symptoms of dementia and Alzheimer’s disease to be aware of (Image: Express.co.uk)
The ADSP includes ethnically diverse participants, with the population-specific assessments focusing on white/European-ancestry, black/African-American, and Hispanic/Latino subgroups, as well as a multi-population meta-analysis.
Historically, black and Latino populations have been underrepresented in genetic studies of Alzheimer’s disease, despite having a higher prevalence of the disease than other ethnic groups.
Dr DeStefano added: “Including participants that represent diverse genetic ancestry and diverse environments in terms of social determinants of health is important to understanding the full spectrum of Alzheimer’s disease risk, as both the prevalence of the disease and the frequencies of genetic variants can differ among populations.”
She added that though the sample sizes in the population-specific analyses were small, meaning the team had limited ability to detect associations.
“We replicated known population differences for the APOE gene, which is one of the best-known and strongest risk genes for Alzheimer’s disease,” she said.
In future studies, the researchers hope to examine the population-specific variants they identified in much larger sample sizes, as well as explore how these variants affect biological functioning.
Co-senior author Dr Gina Peloso added: “We are currently working on expanding this research to be able to use whole genome sequencing with larger sample sizes in the ADSP to be able to look at the full array of genetic variants, not only within known Alzheimer’s disease genetic regions, but across the whole genome.”
The NHS lists common symptoms of Alzheimer’s disease as:
- Memory problems
- Confusion, disorientation and getting lost in familiar places
- Difficulty planning or making decisions
- Problems with speech and language
- Problems moving around without assistance or performing self-care tasks
- Personality changes, such as becoming aggressive, demanding and suspicious of others
- Hallucinations (seeing or hearing things that are not there) and delusions (believing things that are untrue)
- Low mood or anxiety.
If you or someone you know is experiencing symptoms you should speak to a doctor.
