In another edition of the Grand Round at Hospital Moinhos de Vento, the invited experts sought to bring a new perspective on genetics, normally associated with rare diseases. With the theme “The genetics of common diseases”, the event addressed the main applications of genetic tests, the genetics of cardiovascular diseases and the perspectives for the area.
“There is a new path being followed – new causal mechanisms of the most prevalent diseases, such as hypertension, diabetes, the entire range of oncological diseases, and we are seeing an increasing definition of genetic panels that define these diagnoses”, explained the Hospital’s medical superintendent Moinhos de Vento, Luiz Antônio Nasi.
In addition to helping to diagnose diseases – both rare and common –, genetics appears as an alternative for outlining prognoses and making therapeutic decisions. This is because, based on the definition of the genetic code, doctors can analyze and interpret which changes in DNA affect the different proteins in the body.
“We have methodologies that analyze the complete genome as a whole – and it is worth highlighting that genetic diseases, by definition, are any diseases that involve DNA. In other words, all neoplasms have DNA alterations, but not all are hereditary, for example”, highlights Osvaldo Artigalas, geneticist at Hospital Moinhos de Vento.
The advantage of so-called genetic panels is the possibility of carrying out focused tests in order to analyze the main genes that have variants associated with an increased risk of developing a specific disease or group of diseases. “If I know that the patient has a cardiovascular disease, I will not read all the genes responsible for neurological changes. Our challenge today is no longer to sequence DNA. It’s about interpreting all the data”, explains Artigalas.
To exemplify the theme of the event, the geneticist cites the oncology area. “Around 10% of breast cancer cases are hereditary. In 2023, we had 73 thousand new cases. More than 7,000 women diagnosed as a result of a genetic variant, which they were born with, could have undergone genetic testing during an asymptomatic period, with time to take preventive measures and avoid diagnosis, in addition to reducing public health costs,” clarifies.
The next steps, according to Santiago Alonso Tovar, biologist and researcher at Proadi-SUS, are towards precision medicine. “Gene therapy should be the next big thing. In addition to being able to personalize medicines for those with specific mutations, it will be possible to direct the drug to act on that specific target. Gene editing goes hand in hand with nanotechnology – and when we talk about nanostructures, it is a separate universe, very versatile, which can be used in a range of medicines”, he reflects.
Cardiovascular genetic diseases
The prevalence of monogenic cardiovascular genetic diseases (which affect a single gene), such as cystic fibrosis, Huntington’s disease and sickle cell anemia, is 5% to 10%. Polygenic diseases, however, are still beginning to be recognized. Although some panels already exist, there is still no possibility of establishing definitive diagnoses based on them.
In the case of monogenic diseases, the main objective of genetic tests is to facilitate diagnosis. “We have phenotypes that resemble several diseases. When we define a diagnosis, I can tell the patient that he has hypertrophic heart disease, for example. And this is essential, because it determines which tests we should do and which paths we can follow”, details Fernando Luís Scolari, cardiologist at Hospital Moinhos de Vento and researcher at the Institutional Development Support Program of the Unified Health System (Proadi-SUS) .
Hypertrophic cardiomyopathy is actually quite common – if the individual carries the mutation, there is a 46% chance of developing it.
