A massive new genetic analysis reveals that the biological traits underlying autism risk are the same across people of different ancestral backgrounds. By examining the DNA of thousands of Latin American individuals, researchers showed that rare genetic changes linked to autism occur in the exact same genes across diverse populations. The results, published in the journal Nature Medicine, point to a universal genetic foundation for autism and highlight the need for more inclusive medical testing.
Over the past decade, researchers have identified dozens of genetic variations that increase the likelihood of a person developing autism. These variations tend to appear in highly conserved genes. A highly conserved gene is a segment of DNA that has remained nearly identical across species over vast stretches of evolutionary history.
Because these specific genes perform basic cellular functions, they are subject to strict natural selection. Any spontaneous mutations within them are usually weeded out over time because they disrupt essential biological processes. When such rare mutations do occur in humans, they often lead to profound neurodevelopmental changes.
Most of the DNA databases used to discover these autism-linked genes rely almost entirely on people of European descent. This lack of global representation leaves open a major question about whether the genetic traits tied to autism look different in other parts of the world. It also creates real-world problems in medical clinics when patients seek genetic counseling. When individuals of non-European descent undergo genetic testing, they often receive inconclusive results simply because their genetic variations do not appear in standard reference databases.
To close this gap, an international team of researchers formed the Genomics of Autism in Latin American Ancestries Consortium. Marina Natividad Avila, a researcher who led the study, worked alongside Joseph D. Buxbaum, director of the Seaver Autism Center for Research and Treatment at Mount Sinai. The team wanted to determine if the genetic risk factors for autism vary depending on a person’s ancestry. They specifically focused on Latin American populations, which represent a large and genetically diverse group with Indigenous American, African, and European heritage.
The researchers gathered and analyzed genetic material from more than 15,000 individuals across North, Central, and South America. This group included approximately 4,700 people diagnosed with autism, along with their parents and unaffected siblings. By comparing the DNA of children with autism to the DNA of their parents, the team could identify spontaneous mutations.
These spontaneous mutations are newly occurring genetic changes that are present in a child but absent in both parents. To find the specific genes involved, the team used advanced DNA sequencing techniques that read the genetic code. They focused on the exome, which is the specific portion of the genome that provides the instructions for building proteins. Although the exome makes up a tiny fraction of our total DNA, it contains the vast majority of known disease-causing mutations.
The researchers looked closely for rare, spontaneous mutations that alter or destroy how a protein functions. They then compared the rates of these disruptive mutations in children with autism against the rates in children without the condition. Through this mathematical analysis, the research team identified 35 specific genes strongly tied to autism within the Latin American group. When they compared these 35 genes to the ones previously found in European populations, they noticed a massive overlap.
The biological pathways impacted by these genes remained entirely consistent across the two groups. For instance, both populations showed mutations in genes responsible for regulating how neurons communicate with one another in the brain. They also found disruptions in genes that control the cytoskeleton, which is the internal structural scaffolding of a cell. These findings show that the microscopic cellular mechanisms leading to autism are fundamentally the same worldwide.
The underlying biology appears to operate completely independently of a person’s ethnic background. The team also evaluated the mathematical tools used by scientists to measure how conserved a gene is. Because these tools were originally built using European DNA data, the researchers wanted to test their accuracy in a diverse Latin American group. They found that these tools remain highly accurate for the most essential genes associated with autism.
This means that a mutation in a highly conserved gene carries the same biological weight regardless of a person’s ancestry. Ultimately, the genetic changes driving autism likelihood were not restricted to any one ancestral group. “Our results indicate that the core genetic architecture of autism is shared across ancestries,” Buxbaum said. “This suggests that the biology underlying autism is universal and reinforces the importance of ensuring that diverse populations are represented in genetic research.”
Despite these clear biological similarities, the researchers noted a few important limitations to their work. When the team used standard clinical software to interpret the mutations they found, the software flagged fewer of them as definitively harmful in Latin American individuals compared to European individuals. In clinical genetics, a definitively harmful mutation is known as a pathogenic variant. This diagnostic discrepancy happens because current clinical tools rely heavily on past data, which is heavily biased toward European genomes.
As a result, non-European individuals might still receive less definitive answers from standard genetic tests. Additionally, the study mostly relied on sequencing only the protein-coding regions of the genome, rather than the entire DNA sequence. This approach makes it difficult to map out exactly which specific ancestral background a given genetic variation originated from. In heavily mixed populations, tracking the exact origin of a small DNA segment requires full genome data.
Unmapped structural changes in the DNA of less-studied populations might also hide certain genetic risk factors. To fix these clinical blind spots, researchers must continue to sequence the DNA of diverse populations around the globe. Adding more non-European genomes to medical databases will help refine the tools used to diagnose neurodevelopmental conditions. As these databases grow, doctors will be able to provide better, more accurate genetic counseling to families of all backgrounds.
These future efforts will help ensure that the benefits of precision medicine reach everyone. Medical testing must catch up to the reality that human biology shares a common foundation. “These findings provide a road map for improving genetic diagnosis across ancestral groups,” Buxbaum added. “Expanding genomic research in underrepresented populations is essential to reducing health disparities and advancing precision medicine for autism and related conditions across all ancestral populations.”
The study, “Deleterious coding variation associated with autism is shared across ancestries,” was authored by Marina Natividad Avila, Seulgi Jung, F. Kyle Satterstrom, Jack M. Fu, Tess Levy, Laura G. Sloofman, Lambertus Klei, Thariana Pichardo, Dalia Marquez, Christine R. Stevens, Caroline M. Cusick, Jennifer L. Ames, Gabriele S. Campos, Hilda Cerros, Roberto Chaskel, Claudia I. S. Costa, Michael L. Cuccaro, Andrea del Pilar Lopez, Magdalena Fernandez, Eugenio Ferro, Liliana Galeano, Ana Cristina D. E. S. Girardi, Anthony J. Griswold, Luis C. Hernandez, Naila Lourenço, Yunin Ludena, Diana Núñez-Ríos, Rosa Oyama, Katherine P. Peña, Isaac Pessah, Rebecca Schmidt, Holly M. Sweeney, Lizbeth Tolentino, Jaqueline Y. T. Wang, Lilia Albores-Gallo, Lisa A. Croen, Carlos S. Cruz-Fuentes, Irva Hertz-Picciotto, Alexander Kolevzon, Maria Claudia Lattig, Liliana Mayo, Maria Rita Passos-Bueno, Margaret A. Pericak-Vance, Paige M. Siper, Flora Tassone, M. Pilar Trelles, GALA Consortium, The Autism Sequencing Consortium (ASC), Michael E. Talkowski, Mark J. Daly, Behrang Mahjani, Silvia De Rubeis, Edwin H. Cook, Kathryn Roeder, Catalina Betancur, Bernie Devlin, and Joseph D. Buxbaum.
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