2023-05-10 18:09:11
We all carry an operating manual in our DNA, it is our genome. Science has a reference map made from very few people, which is not enough to cover human genetic diversity, which can only be reflected in a pangenome, the first draft of which is published this Wednesday by the journal “Nature”.
Double helix structure of the DNA of the human genome. EPA PHOTO PA/ Matthew Fearn
A large group of researchers has participated in this project, including Spaniards, directed by the International Human Pangenome Reference Consortium (HPRC)).
He director of the Human Genome Reference Program, of which the HPRC is a partEric Green, has considered in a virtual press conference that this is “an incredible scientific achievement, which provides an expanded vision of the DNA of humanity.”
A high-quality pangenome, which increasingly reflects the diversity of the human population, will allow “scientists and health professionals to better understand how genomic variants influence health and disease and move towards a future in which medicine genomics benefits everyone,” he said.
The genome is often compared to a book of life, which contains the DNA instructions that help each living thing to develop and function, or to a map that reflects where each gene is and what it does.
This first draft of the human pangenome combines the genomic sequences of 47 genetically diverse people, and since each of us has one pair of each chromosome, a total of 94 different sequences have been achieved, said Benedict Paten of the University of California (USA). .UU).
51% of these sequences are of African origin (where the greatest human diversity is); 34% American, 13% Asian and only 2% European, as the latter was already widely represented in the reference genome available up to now.
The goal is to increase the number of people to 350 by mid-2024 and reach 700 sequences by the end of the project.
The pangenome adds to the current 119 million base pairs (the chemical units that make up DNA), which will help researchers study regions of the genome for which there were no references before, and “potentially be able to associate structural variants with diseases in the future.” studies”, indicates a statement from the University of California.
A reference human genome is a genetic sequence agreed upon as a template. When scientists and doctors study an individual’s genome for variations, they compare their DNA to the standard to determine where there are differences.
First draft of the human genome in 2001
The first draft of the human genome was presented in 2001 and the final version was completed a year ago. Its use has made it possible to identify genes involved in specific diseases and to trace the evolution of human traits.
But it was far from perfect, among other reasons because it was built from the genetic profile of about twenty people (70% of only one), mostly of white and European origin.
The genome of two people is, on average, more than 99% identical and it is the small differences that contribute to the uniqueness of each one.
Understanding and cataloging what is different “allows us to understand how cells and their biology work, as well as genetic differences and how they contribute to disease,” he explained. Karen Miga, from the University of California.
Paten summarizes that what is being done “is to redesign the foundations of genomics to create a diverse and inclusive representation of human variation as the fundamental reference structure and thus mitigate bias”, a fundamental aspect if “we want the future of precision medicine benefits everyone equally.”
The scientist has expressed his appreciation to the extensive team of researchers, including the Barcelona Supercomputing Center and the Autonomous University of Barcelona, who have contributed to this project.
The pangenome will delve into diseases
Using advanced computational techniques to align the multiple genomic sequences in a single reference, the researchers constructed a pangenome in which each assembly covers more than 99% of the predicted sequence with greater than 99% accuracy.
While the previous reference genome sequence was single and linear, the pangenome represents many different versions of the sequence at the same time, explains a statement from the National Institute for Human Genome Research (USA).
He geneticist from the Open University of Catalonia Salvador Macipwho does not participate in this project, highlighted to EFE the relevance of the pangenome, which will be useful for studies of diseases, their prevalence and variants that can be associated with diseases.
“If, as up to now, there are only variations that are mostly white and European, it is not possible to deduce what happens to a person who does not fit this profile,” he pointed out.
The international consortium has focused both on the accessibility of the data and on the ethical aspects and the social and legal implications of the project, for which there is a specific group.
These experts work to help guide informed consent, prioritize the study of the different samples and collaborate with the international and indigenous communities to incorporate their genomic sequences, said the University of Santa Cruz.
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