A blood test based on the analysis of chromosomes could afford, according to its inventors, to determine the biological age of patients, and thus to estimate their life expectancy. The public will he love this concept?
A promising blood test to determine the biological age of people using it, and therefore potentially to estimate the time they have left to live, is expected to begin this year, according to British newspaper The Independent. The Spanish company, Life Length, causing the already controversial test was created last September. Considering themselves as “the first biotechnology company that measures the telomere, the company relies on the expertise of one of its founders, Maria Blasco, a scientist with the National Center for Cancer Research (CNIO) in Madrid.
Telomeres, these pieces of DNA found at the ends of each chromosome, are a kind of protective cap of the gene pool. Listed Nobel Medicine and Physiology in 2009, they come in the form of short sequences (six nucleotides TTAGGG) repeated many times, so that their succession confers telomere length of up to 15,000 bases or more.
Biological age is not chronological age
But everything depends on the “biological age” of cells. Indeed, telomeres tend to shorten over time and the events they undergo. For each round of mitosis, DNA is replicated by the enzyme responsible for copying the genome (DNA polymerase) for a single mother cell can give rise to two daughter cells each with the entire genetic . Telomeres, which are at the end of the chromosome, are hard copied by DNA polymerase, and finally lose some of the many repetitive sequences.
This is not serious in itself, since it is an unavoidable phenomenon, corresponding to the natural aging process. It is the accumulation of these shortenings that ends up being harmful, causing cell death, disease and even cancer. In addition to cell divisions, other events, such as oxidation or inflammation can promote premature telomere shortening. A little healthy lifestyle (tobacco, alcohol, fatigue, stress …) can cause accelerated aging, where the chronological age (actual length) is more aligned with biological age (state of cells ).
Work had already allowed for a correlation between telomere length and risk of earlier development of age-related diseases such as Alzheimer’s, cardiovascular diseases or disorders of the immune system. According to some studies, the length of telomeres thus directly influence life expectancy.
Knowing the time of his death for 500 euros
The test proposed by Life Length can then estimate the age of cellular customers by measuring telomere length in blood cells. The technology is based on the Q-Fish (hybridization or quantitative fluorescence in situ), a fluorescent probe that binds to the telomere, in proportion to the length thereof. The company said the intensity of fluorescence is therefore representative of biological age.
A News Life Length ensures that this is a test far more accurate than other currently marketed (including SpectraCell Laboratories). It would indeed be able to determine cell by cell telomere length and thus determine the sequence of the shortest (and most dangerous), where others are content to measure an overall average. Its cost would amount to 500 euros and should appeal to patients who would like to know if they live long or not …
It is important to remember that the results of this test are indicative only and may not, at present, determine the time left to live. Scientists are already concerned about the use that can be done by bad people, trying to use this information to sell products antiaging miracles, or to refuse certain services because of too short telomeres.