In The Politics of Autism, I discuss various ideas about what causes the condition. Genetics plays an important role.
A new study, co-led by researchers at the Icahn School of Medicine at Mount Sinai and published March 30 in Nature Medicine, demonstrates that genes associated with autism risk are largely the same across people of different ancestries. The findings, based on one of the largest genomic studies of Latin American individuals to date, provide strong evidence that the genetic architecture of autism is consistent across diverse populations. They underscore the importance of expanding genetic research beyond individuals of European ancestry.
Over the past decade, scientists have identified numerous rare genetic variants that confer substantial risk for autism and other neurodevelopmental disorders. However, most of these discoveries were made in cohorts composed predominantly of individuals of European ancestry, leaving open the question of whether autism's genetic underpinnings differ across populations. This knowledge gap has contributed to disparities in genetic testing, including higher rates of inconclusive results among non-European individuals due to limited reference data.
To address this issue, the research team analyzed exome and genome sequencing data from more than 15,000 Latin American individuals across North, Central, and South America, including approximately 4,700 individuals diagnosed with autism. Latin American populations represent the largest recent mixed-ancestry group globally, with heritage that frequently includes Indigenous American, West African, and European origins. This rich genetic diversity provides a powerful opportunity to refine gene-disease associations, which can improve health outcomes for all populations.
The study examined more than 18,000 genes for enrichment of rare, deleterious coding variants—genetic changes that can have immediate and profound clinical implications for diagnosis, treatment, and family counseling.
Consistent with prior research, rare, deleterious variants in highly conserved genes—genes that remain similar across species and populations over long periods of time—were disproportionately observed in individuals with autism. Researchers identified 35 genes significantly associated with autism in the Latin American cohort. These genes showed extensive overlap with those previously identified in genome-wide studies of individuals of European ancestry. The findings also provide support for several recently identified "emerging" autism-associated genes.
"Our results indicate that the core genetic architecture of autism is shared across ancestries," said study senior author Joseph D. Buxbaum, Ph.D., Director of the Seaver Autism Center for Research and Treatment at Mount Sinai. "This suggests that the biology underlying autism is universal and reinforces the importance of ensuring that diverse populations are represented in genetic research."
