You know the depressing story about the miserable results of efforts to find a way to prevent or treat Alzheimer’s disease.
The results have been so bad that some participants in the recent Alzheimer’s Association conference suggested that the United States should shift cash toward care, and away from medical research, because the money spent on medical research so far has not done much good.
That pattern could continue, but one new tool dementia researchers now have in their labs is access to reasonably affordable machines that can read strands of DNA, and similar substances that carry genetic information, quickly and accurately.
Just thirty years ago, getting even a tiny bit of gene sequence information meant trapping lab assistants in a lab for long, arduous days of extracting genetic material and using complicated, Rube Goldberg methods to find out which nucleotides, or DNA sequence letters, were in the sequence. Getting even a tiny bit of information about genetic sequences was difficult and expensive.
Scientists could get some idea about what was going on in a human’s, or another organism’s, genes by looking at the organisms, or tiny snippets of genetic sequence information, and that was about it.
Now, scientists with grant money can buy “high throughout put sequencing” systems, or “next generation sequencing” systems, that can do in a few hours many times more sequencing work than what assistants used to be able to do in months in the lab.
Illumina, for example, says its HiSeq X Ten system can sequence an entire human genome for about $1,000 per genome.
Instead of just decoding the letters on the cover of the Book of Life, researchers can look closely at all of the letters in many different people’s books of life. Understanding what words those letters actually spell, and how the words work together, will take decades, or centuries, but the researchers already have a new way of seeing old problems.
For five ways sequencing could help researchers make many long-term care insurance (LTCI) claims vanish, and eventually lower claims far below what issuers had expected, read on.
1. New sequencing systems can help researchers skim entire populations for interesting genes.
One group of researchers, described in an article in the Annals of Translational Medicine, found a rare gene in Iceland that seemed to triple the risk of developing Alzheimer’s disease, then found the same gene seemed to have the same effect on people living in the United States, Norway, the Netherlands and Germany.
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2. The new systems speed up efforts to find mutations that affect specific groups of people.
Scientists have been doing that for years, and they found the gene described in the Annals of Translational Medicine article by looking in Iceland. But now sequencing is cheap enough that genealogy hobbyists can do crude versions of that work for fun.
In a recent article in Molecular Genetics & Genomic Medicine, researchers describe using that kind of approach to quickly find 12 candidates for further research in Caribbean Hispanic people from families with four more relatives affected by dementia.
3. The new systems can help scientists learn more about the letters that don’t seem to actually affect how organisms work.
Researchers have divided the sections of nucleotides, or genetic letters, in genes and related types of substances, such as RNA and proteins, into two types: coding and non-coding.
Researchers understand how the coding sequences get cells, or entire organisms, to grow and act. They don’t really know why genes contain the non-coding sequences, if those sequences do actually serve some subtle purpose or, whether the sequences do anything or not, they can give scientists useful information about how genes work.
Now, researchers have so much sequencing power they can use it to look more closely at non-coding sequences. One group used the systems to analyze 37 million mutations in 1,000 genomes. They found that, for whatever reason, some types of mutations seem to help the people who have the mutations and become more common over time, according to an article they published in PLoS One..
The researchers also found that some mutations in the non-coding sequences seem to have a correlation with conditions such as Alzheimer’s disease, and the form of cognitive impairment associated with diabetes.
The results suggest that the non-coding sequences may have an important biological function that researchers ought to know about, the researchers conclude.
4. Scientists could use the new sequencing systems to improve screening of drugs.
A group reported in June, in the journal Neurobiology of Disease, about using fast sequencing technology to test the effects of bexarotene, a distant cousin of Vitamin A, on mice with human Alzheimer’s genes. Bexarotene seems to help mice with Alzheimer’s genes think better, but no one has known why.
The researchers “read” large batches of the genetic material of the mice and found that bexarotene accelerated cells’ ability to break up beta amyloid, a protein associated with Alzheimer’s.
The study showed why bexarotene seems to help the mice think better, and it also confirms that reading large amounts of organisms’ genetic material can be a good way to understand the relationship between cell hormone receptors and Alzheimer’s disease, the researchers say.
5. Scientists could use the sequencing technology to understand how specific sections of the brain work.
In an article in Biochimica et Biophysica Act – Proteins and Proteomics, researchers said they can use the sequencing systems to identify and analyze “unidentified and elusive proteins” in the hippocampus, a part of the brain that plays an important role in learning and memory.
Another suggested, in the Annals of Neurology, that they used the new sequencing systems to identify a substance, rs3796529, that seems to keep the hippocampus of an individual with mild cognitive impairment from shrinking quickly.
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