What is the importance of the human genome and what potential does it have to cure diseases

No one can argue that the year 1953 was fraught with important events. It was the year when Republican Dwight D. Eisenhower took office as president of the United States or that Queen Elizabeth II was crowned at Westminster Abbey in the United Kingdom.

“I like to remember how important 1953 was in its extremes. On April 25, 1953, the discovery of the double-helix structure of DNA by scientists Francis Crick, from Great Britain, and James Watson, from the United States, was published in a barely one-page article, in the journal Nature. And on May 29, man reaches the top of the highest peak on the planet, Mount Everest and achieves the widest and most amazing gaze of nature on Earth. These are two milestones that mark the conquest of something so small and so big for humans. Two milestones that connect nature too,” Dr. Federico Prada, biologist and Dean of the Faculty of Engineering and Exact Sciences of the UADE, explained to Infobae, who with this memory highlights today's celebration, World DNA Day.

“DNA, or deoxyribonucleic acid, is the material that contains hereditary information in humans and almost all other organisms. For many it is the deepest and most reductive look that has ever been had of this emerging property of matter called life. With a history that exceeds 3.5 billion years of life, of natural selection and evolution, today DNA can reveal to us the secret it holds in its atoms and electrons,” added Prada.

According to the Doctor of Science from the Leloir Institute, the discovery was an arduous and downward path to the discovery of DNA. “From that moment on in the history of molecular biology, a second stage began, an upward path that integrated knowledge to reach the central dogma of molecular biology, the first steps in genetic engineering, the emergence of biotechnology and then the sequencing of the human genome made us to reach a second peak where systems biology is located. Professionals who work in the area of health, such as doctors, biologists, biotechnologists, biotechnologists, biochemists and bioinformatics, seek to integrate and understand the functioning of the human body with the prediction of the onset of diseases and thus find the drug that will work best for treat a certain disease. That is the integrative or systems biology that we are experiencing today,” said Prada.

“The study of the genome implies eras of genomics. A first era was born in 1986 with the term genomics. Genomics magazine coins that term. The genome began to be studied until it started sequencing in 2001. Until this year, it was possible to fully decode the human genome. With what we have, we have to 'make it speak to the genome' and analyze the information from so much data it contains. That's what nature variability is all about. The richness of life is there, in the study of millions of sequenced genomes. Variability, regulation of the genome (how it is expressed) and modification of the environment (epigenetics), make this genomic era in the 21st century. Translated..., it is terribly important for the study of diseases,” Prada added.

He concluded: “Information is key, but the environment is more so. Knowing genetic information is the first step, but it must be integrated into environmental information, such as seeing the parameters that make a person's life (food, lifestyle). Systematically identify with artificial intelligence tools to discover the secrets of pathological tissue, for example, of a tumor. That is why the study of biosciences, especially biotechnology and bioinformatics, is key to this genomic revolution that we are experiencing.”

An incredible genetic breakthrough

In June 2000, the Human Genome Project (HGP) and the private company Celera Genomics announced the first “draft” of the human genome, the result of 10 years of work and $3 billion invested that was classified as one of the greatest feats of exploration of history, because instead of having started a journey to a distant planet, HGP was an inner journey of discovering the map of all our genes, those of our own species, Homo sapiens.

After announcing the beginning of the genomic study of human DNA, a team of scientists succeeded in assembling the entire genetic plane of human life, adding the missing pieces to a puzzle that was almost started more than two decades ago. In a research published in the journal Science, the group of international researchers described the first sequencing of the entire human genome, that is, the set of instructions for building and maintaining a human being. Previous work, held around the world, was incomplete because DNA sequencing technologies of the time were not able to read certain genomic regions. Even after the updates, about 8% of the genome was missing.

And why is it important to have deciphered that remaining 8% of our genome? Areas with repeated DNA bases, such as those missing in the HGP genome, have since been linked to many health problems, from ALS and Huntington to cancer and autism. By sequencing them, scientists believe that we might be better equipped to study and treat these conditions. Scientists said that this comprehensive picture of the genome will give humanity a greater understanding of our evolution and biology, while also opening the door to medical discoveries in areas such as aging, neurodegenerative diseases, cancer and heart disease.

Hernán Dopazo, PhD in Biological Sciences and Independent Researcher (CONICET), explained that the future will hold, now that this missing 8% was unraveled. “In the very near future, the costs for genetic testing will fall. Today to make a genome, it costs about 1000 dollars. But all the technological increase we are experiencing tends to make it more accessible in the near future. Thus, today we have genetic analysis at hand to detect diseases and even the possibility of correcting some genes with the Crispr scissors. Nothing could happen if we didn't have this technology. And this technology could not be without the sequence of the human genome,” Dopazo said.

“Scientists made progress in decoding the genome, but they were missing regions that were very difficult to find. It's how to order something when there are large repetitions, similar, regions that were missing that 8%. This year the whole process was completed. During this time of waiting, there were very impressive projects, from 2003 to 2018 by two international consortia to see the genetic variability of all the world's populations and diversity of the human population. It is to analyze megabases or gigabases of information about the human genome, which has 3 billion letters,” said the expert, who hopes that the recent discovery will help in the advancement of finding cures for more than 300 genetic diseases.

“We are increasingly reaching knowledge about ourselves with greater depth and accuracy. Having sequenced the entire human genome will help avoid various diseases. And also, understanding the mechanisms of origin of a given pathology will help to develop more direct and precise drugs against diseases so that they have a lower prevalence”, Dr. Jorge Dotto, a world reference as a geneticist, explained to Infobae, who has extensive experience in The United States and Europe.

He added: “This complete information will allow us to make better decisions about our body, since it changes the perception of the ignorance we had. For example, the decision of what foods we need to eat to strengthen our defenses. In our microbiome is 80% of our immune system. Knowing more about the microbiota and what probiotics, which are living bacteria, we need to incorporate will help us modulate and make more effective the functioning of our immune system, which could be more precise to reduce inflammation at the molecular level in our body in the face of a disease”.

In addition to exemplifying with the gut microbiota, Dotto also referred to improvements in the behavior of the skin and the female reproductive system. “We have to help people get less sick, and this work of total genetic sequencing is going to help us do that,” the specialist concluded.

Humans have 46 chromosomes, in 23 pairs, representing tens of thousands of individual genes. Each gene consists of several base pairs composed of adenine (A), thymine (T), guanine (G), and cytosine (C). There are billions of base pairs in the human genome. But the genome that the researchers sequenced didn't come from a person, but from a hydatiform mole, a rare mass or growth that forms inside the uterus at the beginning of a pregnancy. This tissue forms when the sperm fertilizes an egg without a nucleus, so it contains only 23 chromosomes, such as a gamete (sperm or egg), instead of the 46 found in the DNA of a human cell. These cells simplify the computational effort but can be a limitation.

The consortium explained that its work increased the number of DNA bases from 2.92 billion to 3.05 billion, an increase of 4.5%, and that the count of genes encoding proteins increased by only 0.4%, to 19,969. According to experts, the work may also lead to other new knowledge, including those related to how genes are regulated.

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