You’ve probably heard about the term “Precision Medicine”  in the headlines recently, right? Yes, I knew it. So, have you ever wondered how it is and will continue to affect your life and everybody else’s? In the next lines we will try to briefly introduce this theme and provide practical examples. So stay tuned.
Precision Medicine is the new concept of giving to every patient the right treatment, in the right dosage, at the right time, avoiding collateral effects and unnecessary, costly treatments. How is that possible? First we have to know you, really know you, in a molecular level.
Genetic tests are powerful tools that, together with medical records, guide doctors towards the most appropriate treatment. Nowadays, clinical laboratories provide a wide range of genetic tests. Let’s get to know a few of them.
DNA sequencing allows us to know our genetic code, present in our body cells. With this technology it is possible to read small specific parts or even the whole genome, from healthy or tumorous samples. Whenever you need to know your predisposition for cardiovascular or neurological diseases, confirm a clinical diagnosis for a specific gene or even try to discover the genetic cause of an unknown disease, there will be a genetic test
available for you .
Oncology treatments will also benefit. Not every cancer is the same disease, in fact, not even every breast cancer is the same! There are several different molecular features that leads to different types of breast cancer. The right genetic test may elucidate the genetic cause and indicate the best available drug.
DNA fragments derived from tumorous cells can be found in small proportions in our bloodstream. Massive DNA sequencing from bloods samples is a non-invasive technique that can spot those fragments, allowing for early cancer detection and monitoring of treatment response and cancer reappearance .
Chemo and immunotherapies
Genomic instability is a common feature in fast growing tumorous cells , that can present accumulation of point DNA alterations or even whole extra chromosomes. Depending on how unstable a cell genome is, it may be more susceptible to certain treatments, as the defective cell may not recover from another challenge and shortly die or it can be more susceptible to the immune system . That is the principle behind some genetic tests that measure how damaged is the cancer genome and, therefore, how likely it is to respond to some chemo or immunotherapies.
Our metabolisms process medicines in different ways. Why? There are different genes responsible for drugs metabolism, and people have different versions (isoforms) of those genes. Cytochrome P450 (CYP) enzymes are the main players in the majority of all drugs metabolisms, and there are hundreds of isoforms out there. Depending on your genes, you may be fast, normal or really slow at processing a medicine, which may influence in the correct treatment, dosage or collateral effects . Scientists are in their way to discover all gene-drug interactions, and a sort of pharmacogenomic tests are already available.
A number of companies have being offering custom genetic tests, promising that you will get to know you better with just a saliva drop. Well, with a few regards and at the best of the modern scientific literature, they are telling the truth. Nutrigenetics, predisposition to Type II Diabetes or Alzheimer disease, fitness aptitude, hereditary history, if you are good or not with bitter flavors… You name it, it is available. Just get to know the limitations of each result, follow the references, think twice about what you really want to know, take care of your genetic information and have some fun.
You are probably aware that our body have much more microorganism cells than our own cells. They live in our skin, mouths, intestines, etc. Microbiome tests are in the initial stages of development and will soon begin to provide hints on what are the main characteristics of our individual microorganisms and how these little fellows may have great influence in different aspects of our lives .
Those are just a few examples and this list is growing in a fast pace. Precision Medicine wants to get to know you, and someday, we will all be genetic tested somehow. Are you ready?
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 Heitzer, E., Haque, I.S., Roberts, C.E.S. et al. Current and future perspectives of liquid biopsies in genomics-driven oncology. Nat Rev Genet 20, 71–88 (2019).
 Ferguson LR, Chen H, Collins AR, et al. Genomic instability in human cancer: Molecular insights and opportunities for therapeutic attack and prevention through diet and nutrition. Semin Cancer Biol. 2015;35 Suppl(Suppl):S5–S24.
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 Weinshilboum RM, Wang L. Pharmacogenomics: Precision Medicine and Drug Response. Mayo Clin Proc. 2017;92(11):1711–1722.
 Allaband C, McDonald D, Vázquez-Baeza Y, et al. Microbiome 101: Studying, Analyzing, and Interpreting Gut Microbiome Data for Clinicians. Clin Gastroenterol Hepatol. 2019;17(2):218–230.