When it comes to genetic diversity, Brazil has just struck a major blow. A team of Brazilian researchers recently identified 8.7 million totally new genetic variants in the country’s population. That’s a huge number! To give you an idea, it’s like discovering an entire new genetic library that had remained hidden until now. This discovery confirms what many already suspected: genetic diversity in Brazil is probably the most exceptional in the world.
A game-changing scientific discovery
The figures speak for themselves. By analyzing the complete genomes of over 2,700 Brazilians, scientists have uncovered 8.7 million genetic variants never before recorded. To put this in perspective, these new variants represent over 11% of all those identified in the study. That’s a colossal number!
Among these discoveries, 36,637 rare and potentially harmful variants were identified. These variants are particularly common in people of African or indigenous descent. This tells us a lot about Brazil’s unique history, and the genetic wealth that stems from it.
Major medical implications
This genetic diversity is not just a subject for academic study. It has direct repercussions on public health. The variants discovered affect genes involved in fertility, immunity and metabolism. Some are even linked to specific medical conditions such as hypercholesterolemia, obesity, malaria and tuberculosis.
The complex legacy of Brazilian history and genetic diversity
To understand this exceptional diversity, we need to go back to Brazil’s historical roots. Genetic analysis reveals that the Brazilian population has an average of 59% European ancestry, 27% African ancestry and 13% indigenous American ancestry. This distribution tells a fascinating and sometimes painful story.
Revealing genetic patterns
The study reveals some striking historical details. 71% of Y chromosome lineages come from European ancestry, while mitochondrial lineages are divided between African (42%) and indigenous (35%) origins. This genetic asymmetry bears witness to the historical reality of often unequal relationships between European men and indigenous or African women during the colonial period.
A unique blend of cultures
The peak of interbreeding occurred between the 18th and 19th centuries, a period marked by the gold rush and diamond exploration. This convergence of populations with distinct geographical origins created unique conditions for genetic mixing that are found nowhere else on this scale. Genetic diversity is a direct result of this complex history.
A natural laboratory for human evolution
Brazil is a veritable natural laboratory for understanding human evolution and adaptation. European colonization, which began in the 15th century, brought about one of the greatest demographic upheavals in history. Just imagine: some 5 million Europeans and at least 5 million Africans were brought to a region that was home to over 10 million indigenous peoples speaking more than 1,000 different languages!
Exceptional conditions for diversification
This meeting of such different populations created perfect conditions for genetic diversification. Unlike other countries, where populations have remained relatively homogeneous, Brazil has seen the blending of genetic heritages that had developed separately over millennia.
The Genomas Brasil program: a national ambition for genetic diversity
This research is part of the Genomas Brasil program, launched five years ago by the Brazilian Ministry of Health. The aim? To sequence the complete genomes of 100,000 Brazilians by 2030, in order to implement precision medicine in the public health system. This revolutionary program takes full advantage of genetic diversity.
Impressive logistical challenges
Data collection required some remarkable logistical innovations. To reach the isolated indigenous communities of the Amazon, researchers used a mobile laboratory installed on a boat, navigating the Madeira and Purus rivers. Never before seen!
A rigorous methodology
Samples were collected using a methodical approach:
- 2,111 healthy participants in five different health studies
- 318 Afro-Brazilians participating in a study on chronic kidney disease
- 294 samples from communities of indigenous descent living along Amazonian rivers
Benefits for personalized medicine and genetic diversity
This genetic wealth opens up extraordinary prospects for personalized medicine. As geneticist Lygia V. Pereira of the University of São Paulo: “The fact that we are sequencing the genomes of a population with many African ancestors and quite a few indigenous ancestors means that we can describe millions of genetic variants that have not yet been described anywhere in the world”.
Correcting the biases of global research
This study reveals a major bias in international genetic research. Global genetic databases are largely dominated by white European populations, leaving in the shadows the genetic specificities of African and indigenous populations. Genetic diversity fills this crucial gap.
| Aspect | Traditional research | Brazilian approach |
|---|---|---|
| Study population | Predominantly European | Diverse multi-ethnicity |
| Variants identified | Limited to white populations | 8.7 million new variants |
| Medical applications | Biased towards certain populations | Inclusive and equitable |
| Representativeness | Low diversity | Reflects global diversity |
A fascinating case study: the African variant
One particularly interesting example concerns a genetic variant of African origin that protects against sleeping sickness caused by the parasite Trypanosoma brucei. But here’s the rub: this same variant is associated with an increased risk of developing chronic kidney disease in black Brazilians. This discovery perfectly illustrates the complexity of genetic interactions.
The importance of a personalized approach
This case shows why it’s crucial to study genetic diversity. A variant can be protective in one context and problematic in another. Without this in-depth knowledge, it will be impossible to develop truly effective treatments.
A model for global genetic research
The success of the Brazilian project is inspiring other similar initiatives in Latin America and around the world. This inclusive approach, which prioritizes genetic diversity over ease of sampling, could revolutionize our understanding of human genetics.
Towards more equitable medicine
As Iscia Lopes-Cendes, a physician and geneticist at the University of Campinas, notes: “You want to be able to use this information to provide healthcare for everyone, and leave no one behind. That’s exactly what’s at stake!
“These genomic maps are extremely useful for informing and designing future personalized medicine studies” – Andrés Moreno Estrada, population geneticist at Mexico’s Center for Research and Advanced Studies
Future prospects and practical applications
The implications of this research are far-reaching. Scientists plan to study the specific impact of these variants on Brazilian health. For example, they are interested in genetic variants that increase the risk of breast cancer, traditionally studied mainly in white populations.
Immediate applications in sight
This knowledge will enable us to develop :
- Prevention strategies tailored to Brazil’s specific genetic make-up
- More effective personalized treatments
- Targeted screening protocols based on genetic origin
Towards a global health revolution thanks to genetic diversity
This major discovery positions Brazil as a world leader in genetic research. The 8.7 million variants identified are just the beginning of a revolution that could transform our approach to human health. To further explore these issues of genetic diversity and personalized medicine, pharmacogenomics research at the National Human Genome Research Institute provides a perfect illustration of how a person’s DNA influences their response to medication.
Frequently asked questions
Why is Brazil so genetically diverse?
Brazil owes its exceptional genetic diversity to its unique history of interbreeding between indigenous populations, European colonizers and deported Africans over several centuries. This convergence of distinct genetic heritages has created a diversity without parallel anywhere in the world.
What are these 8.7 million genetic variants?
These variants are variations in DNA that have never before been identified in global genetic databases. They account for over 11% of all variants found in the study, and are particularly common in people of African or indigenous descent.
How will this discovery improve healthcare?
These variants affect genes involved in fertility, immunity and metabolism. Their identification will enable the development of personalized treatments, adapted prevention strategies and more effective screening protocols for the Brazilian population and other similar populations.
How many people took part in the study?
Over 2,700 Brazilians took part in the research, including healthy participants, Afro-Brazilians in kidney disease studies, and members of indigenous Amazonian communities.
What are the objectives of the Genomas Brasil program?
The program aims to sequence the complete genomes of 100,000 Brazilians by 2030 to implement precision medicine in the Brazilian public health system, with an investment of several million dollars.
