Pharmacogenetics

The purpose of personalized medicine is to select the best therapies for each patient in order to ensure the best result and reduce the risk of side effects.

Personalized medicine is a medical approach that aims to personalize medical treatments for the individual patient. Each of us is different and this diversity can affect not only the manifestation of diseases, but also the response to therapies. The extensive knowledge that we have today both on the cause of diseases and on our genome determines two important advantages: on the one hand, they allow us to have drugs aimed at specific molecules involved in the disease; on the other hand, they allow genetic, clinical, environmental and lifestyle information relating to the patient to be taken into consideration. The aim is to select the best therapies for each patient in order to ensure the best result and reduce the risk of side effects.

In the context of personalized medicine, a relevant aspect is precisely that of "pharmacogenetics". This branch of pharmacology studies the individual-specific variability in the response to drugs on a hereditary basis and deals, in a broader sense, with the study of all the genes that can affect the response to therapy (called "drug-genes").

Although the first studies date back to the late 1950s, the most important steps were taken with the sequencing of the human genome and the possibility of genetically characterizing individuals with ever faster and cheaper methods.

Screening for drug genes is spreading, both in the United States and in Europe, and mainly concerns genes that affect anticancer therapies. The studies are concerned with evaluating possible variations in these genes that affect drugs in various ways, determining their efficacy, toxicity, absorption and breakdown.

So far, around 120 drug-genes have been identified and a British study found that nearly 99% of people have at least one variant of a drug-gene. This information allows you to intervene by changing the dose of a drug or replacing it with another, to have better results and avoid serious side effects. In addition to individual patients, a pharmacogenetic approach would be beneficial for the health system; considering the UK, around 6.5% of hospitalizations can be attributed to adverse drug reactions.

Currently the cost of these screenings is still high, so they are not carried out on the whole population. As more information is available and less expensive methods become available, it will be necessary to evaluate the opportunity to screen large populations or to study drug genes in a targeted manner, when a patient is prescribed a drug for the first time.

So let's not be surprised if, in a few years going to the pharmacy or to the doctor, in addition to the health card they should ask us for a pharmacogenetic card. We will know what it is.

Valentina Turinetto

NP Maggio 2022