A recent commentary published on August 8 in the journal Cell reveals that Amazonians are genetically as distinct from Andeans as Europeans are from East Asians when it comes to genetic variants that influence drug responses. These genetic differences can lead to varying side effects for individuals and alter recommendations for drug dosages. The researchers emphasize the necessity of addressing the diversity gap in genomics research by highlighting the genetic variation present among indigenous populations.
Traditionally, Native American groups have been generalized as a singular, homogeneous entity, a stereotype that persists among researchers today. However, the truth is far more intricate. Various influences, including environment, history, and culture, have created significant genetic diversity between the populations in the Andes and the Amazon, despite their proximity of just 150 to 200 miles.
“The high-altitude Andean region is characterized by low oxygen and dryness, while the Amazon region consists of a tropical forest at low altitude. These starkly different environmental challenges can drive genetic evolution and biological adaptation,” states Eduardo Tarazona-Santos, the lead author, from Universidade Federal de Minas Gerais, Brazil. “Additionally, the Andeans and Amazonians have developed unique languages, social structures, and farming practices, which have likely further differentiated them over time through natural selection.”
The research team studied the genomic diversity of 294 individuals from 17 indigenous groups located in the Andes and Amazon. They discovered that specific genetic variations lead to different reactions to medications between Amazonians and Andeans. Notably, a larger proportion of Amazonians possess a variation that enhances their response to rosuvastatin—a drug used to lower cholesterol levels and reduce cardiovascular risk—though it also increases their likelihood of side effects.
According to clinical guidelines, only 2% of indigenous Andeans need a reduced initial dose of rosuvastatin due to potential side effects, in contrast to 16% of indigenous Amazonians. This highlights the necessity of integrating genomics research to ensure precision medicine is effectively utilized.
For warfarin, a medication used to manage blood clots, accurate dosing is crucial. An insufficient dose may be ineffective, while an excessive dose can lead to dangerous bleeding. The researchers found that 69% of individuals from the southern Andes require a lower dose of warfarin, compared to 93% of Amazonians needing a dose reduction.
“The genetic differences affecting pharmacology observed among Andeans and Amazonians are even more pronounced than those between Europeans and Asians,” Tarazona-Santos explains.
While there are alternative anticoagulants to warfarin that do not necessitate meticulous dosage monitoring, these are significantly more expensive—being ten times the cost—making them inaccessible for many in developing nations. Understanding how genetic factors shape drug dosages is essential for ensuring safe and effective use of affordable medications in resource-limited contexts.
The commentary stresses the importance of recognizing the genetic diversity within indigenous populations and warns against viewing ethnic groups as a monolithic entity in genomics research. It advocates for comprehensive genomics research that includes varied populations to promote equitable health care worldwide.
In conclusion, Tarazona-Santos emphasizes that including participants from diverse socioeconomic and ethnic backgrounds in research efforts is vital for studies like this in human genomics. “Engaging that diversity improves research and community involvement, fostering transparency and building trust,” he remarks. “It also makes individuals feel more at ease seeing people from their own community involved.”
