Diagnostic tests, which were positioned as a major scientific breakthrough, are now essential for identifying predispositions to developing different pathologies and for identifying the best therapies. What is the role of biotechnology and precision medicine.
April 25th is World DNA Day,
a date that commemorates the landmark
discovery in biology: the structure
of the molecule that contains the genetic information of all living beings.
This day highlights the importance of DNA not only as a fundamental component of biological inheritance, but also as a tool that enabled significant scientific advances in medicine, biotechnology, and other areas. Since the discovery of its double helix structure by James Watson and Francis Crick in 1953, knowledge about DNA and its function has been key to unraveling the mysteries of life itself.
DNA, despite being a relatively simple molecule, composed of a long chain of nitrogenous bases, is the instruction manual that guides the development and functioning of organisms. This chemical structure stores the information necessary to form a complex organism from a single cell.
Every cell in our body contains copies of this genetic material, which not only defines physical characteristics but also other fundamental aspects such as response to disease and traits inherited from past generations.
“72 years ago, James Watson and Francis Crick published a model in Nature that would forever change our understanding of life: the double helix structure of DNA. That discovery, based in part on the X-ray diffraction images obtained by Rosalind Franklin, laid the foundation for understanding how life encodes its information. The idea that every living being carries an instruction manual in the form of a nucleotide sequence in its cells was, and continues to be, revolutionary,” Adrián Turjanski, PhD in Bioinformatics, a researcher at Conicet and professor at the University of Buenos Aires (UBA)
“Molecular biology flourished in the following decades, and especially in the 1980s, our understanding of how genetic information is transcribed into RNA and translated into proteins began to consolidate. We understood the genetic code, the regulatory mechanisms, the molecular switches that activate or silence genes. It's an entire language that the cell interprets to build and maintain life,” added Gen360's scientific director.
This information is extremely valuable, and living beings preserve it by storing it in the nucleus of our cells. DNA never leaves the nucleus, and only copies (messenger RNA) are sent in the form of individual instructions.
“Towards the end of the last century, the focus shifted to a key question: can we read all this information? Thus, sequencing technologies emerged, allowing us to decode everything from the simplest genomes, such as those of viruses—with just a few thousand bases—to the most complex, such as the human genome, with its more than 6 billion letters. This effort symbolically culminated in 2003, with the publication of the first complete draft of the human genome. It was a pivotal moment, not only for biology, but also for medicine, agriculture, ecology, and many other disciplines,” explained Turjanski, who published the first bacterium sequenced in Argentina and the first human genome for diagnosis.
The creator of the national genomic data system and the first sequencer of yerba mate added: “Since then, we have sequenced millions of genomes, not only human ones, but also those of plants, animals, bacteria, and microorganisms from extreme environments. We use this information to diagnose genetic diseases, design personalized therapies, track epidemic outbreaks, understand how an ecosystem works, and even explore the evolutionary origins of our species. Genomics has become commonplace.”
As described in science textbooks, DNA contains the genetic information of most organisms and is composed of units called nucleotides, four specifically: Adenine (A), Guanine (G), Cytosine (C), and Thymine (T). These four letters alternate, forming long DNA sequences, like a pearl necklace.
This combination does not occur randomly but precisely, as living beings have encoded in these four letters the instructions (genes) for synthesizing all their proteins, the molecules responsible for controlling and executing all the processes that take place in our bodies.
“This discovery opened the door to a deeper understanding of human biology, but this advance would not have been possible without the work of Rosalind Franklin, whose X-ray diffraction image of DNA was fundamental to deducing its structure. More than seven decades later, advances in genetics continue to transform medicine, improving diagnoses and treatments, and opening up new areas of research,” geneticist Gabriel Ércoli
“One of the most visible examples is noninvasive prenatal screening or ‘fetal DNA in maternal blood.’ Using a maternal blood sample, it is now possible to detect certain conditions with high precision, such as trisomies 21, 18, and 13 (Down, Edwards, and Patau syndromes, respectively) and other genetic conditions, which allows for optimized monitoring of pregnancy and birth,” added the specialist, who serves as medical director of Gempre, Genomics and Precision Preventive Medicine.
Genetic tests allow us to determine ancestry, health, predisposition to disease, and response to medications with just a saliva sample - (Illustrative Image: Infobae)
Over the years, DNA has become a centerpiece of scientific advancements. Today, we have access to technologies that allow us to easily analyze our own genetics. Genetic testing, for example, is now accessible thanks to saliva kits that reveal a variety of data about health, ancestry, and other personal aspects.
He added: “Genetics is also making progress in rare diseases (RDD) and complex adult conditions, such as diabetes and high blood pressure. In conditions such as inherited metabolic diseases, genetic testing allows for faster diagnoses, facilitating the early initiation of treatments that can improve quality of life or prevent serious complications.”
Regarding how these genetic tests work, Dr. Ricardo Di Lazzaro Filho, founder of Genera, a personal genomics laboratory, stated: “Through a simple oral swab, which the user performs and sends by mail, we can trace our ancestors and also learn about genetic predispositions related to well-being, health, diseases, and response to certain medications.”
Although genetic tests do not diagnose diseases, they do provide valuable information about predispositions. The results of these analyses can help customize health and wellness plans tailored to the specific needs of each individual. Personalized medicine is an increasingly present concept in modern healthcare, as it allows for tailored treatments for each patient.
One of the most significant advances was the application of nutrigenetics, a branch of genetics that studies how genes influence our response to food. Studies have shown that each person responds differently to nutrients, which explains why some may have food intolerances, vitamin deficiencies, or a tendency to consume more sugar.
In the field of sports, DNA also plays a crucial role, as these tests provide information about physical performance, endurance, and the propensity to develop certain injuries. Furthermore, they allow us to determine the most appropriate type of exercise, which facilitates the optimization of athletic performance and injury prevention. Thus, "our genes" not only inform us about how to take care of ourselves, but also how to improve our quality of life and keep our bodies in the best possible condition.
Understanding the Past and the Future: Ancestry and Predisposition to Disease
One of the most fascinating applications of genetic testing is the ability to trace a person's ancestry. By analyzing mitochondrial DNA and the Y chromosome, it is possible to trace a genetic family tree that not only reveals where ancestors come from, but also human migrations over thousands of years.
This type of analysis also makes it possible to identify distant relatives who may share DNA segments, something that many people are unaware of until they meet new relatives thanks to these tests.
Ancestry analysis, however, doesn't only refer to the past. It can also reveal a greater predisposition to developing certain diseases. "Knowing our genetic predisposition can help us seek counseling and contribute to prevention or early diagnosis," explained Dr. Di Lazzaro.
This is especially useful when dealing with complex diseases such as cancer, diabetes, Alzheimer's, or Parkinson's, where genetics play a significant role in the risk of developing them.
Tests can also predict how an individual might respond to certain drugs. This information is known as pharmacogenetics, and it allows for personalized medical treatments. With the data obtained, doctors can select the most effective medications and minimize side effects, creating a genetic profile that allows for optimized and personalized therapies. The impact of these tests is such that, as Di Lazzaro explains, "curiosity, prevention, or improved well-being" are some of the most common motivations for those who decide to undergo these studies.
In addition to disease prediction, genetic testing can also reveal surprising details about well-being. Characteristics such as sun sensitivity, predisposition to wrinkle formation, the skin's antioxidant capacity, and even the risk of developing osteoporosis are recorded in each person's DNA.
The Impact of Advances in Public Health
The discovery and understanding of DNA has had a profound impact on medicine and public health. In the past, genetic knowledge was limited to a few isolated advances, but today it is an accessible resource for millions of people around the world. Thanks to these types of advances, individuals can learn key aspects of their health, ranging from their response to medications to their predisposition to developing certain diseases.
“Starting in 2015, another revolution began to take shape: gene editing. Tools like CRISPR-Cas9 allowed us to modify DNA with unprecedented precision. What previously required years of laboratory work can now be done in weeks or days. From curing genetic diseases in animal models to developing drought-resistant crops, gene editing has greatly expanded our capabilities for biological intervention,” Turjanski said.
Regarding medical treatments, progress in the field of genetics has allowed for the development of more effective prevention strategies, as doctors can now more accurately identify disease risks and prescribe more appropriate treatments for each patient.
The impact of these advances is not limited to individual health. Genetic research and population studies have identified patterns that contribute to improving public health. By understanding how genetic characteristics affect health, public health policies can be implemented that address the specific needs of certain populations or ethnic groups. This knowledge also plays an essential role in preventing hereditary diseases, helping families make informed decisions about their children's future health.
The discovery of the structure of DNA ushered in a new era in biology, one that completely transformed our understanding of life. Today, genetics not only helps us understand where we come from, but also optimizes our health, improves our lives, and predicts the future with an unprecedented degree of accuracy.
“Seventy years after that double helix drawn in Cambridge, we are still dazzled by our ability—as humanity—to read, interpret, modify, and create life. And this is just the beginning,” Turjanski concluded.
Genetic testing today opens up a vast and fascinating field of possibilities, providing unparalleled access to the information that defines our biology. This is just the beginning of a new era in personalized medicine and human well-being.
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