A new study in Molecular Psychiatry (May 17, 2024) led by Rini Pauly, Layla Johnson, F. Alex Feltus, and Emily L. Casanova explores a fascinating idea: could remnants of Neanderthal DNA contribute to autism?
🔍 What They Investigated
- Compared whole-exome sequencing data from autistic individuals (probands) and their unaffected siblings in the SPARK cohort against ethnically matched controls from GTEx and 1000 Genomes databases—focusing on Black non‑Hispanic, White Hispanic, and White non‑Hispanic groups.
- Tracked Neanderthal-derived single-nucleotide polymorphisms (SNPs)—looking at both common (≥1%) and rare (<1%) variants.
📈 Key Findings
- Rare Neanderthal SNPs Are Enriched in Autism
- Across all three ethnic groups, autistic individuals carried significantly more rare Neanderthal-derived SNPs than controls.
- 25 Brain-Linked SNPs Identified
- The team found 25 Neanderthal-origin SNPs enriched in autistic individuals with evidence of impacting gene expression in the brain (acting as QTLs).
- Links with Epilepsy and Language Regression
- One SNP (rs112406029, in the SLC37A1 gene) was associated with epilepsy, carried by ~67% of White non-Hispanic autistic individuals with epilepsy—8% even homozygous—versus ~22% in controls.
- Other SNPs, like rs1805327 (RAD1) and rs2307073 (USP47), were linked with language regression and epilepsy in Black non‑Hispanic and White Hispanic autistic groups, respectively.
- Not a Boost in Total Neanderthal Ancestry
- Overall Neanderthal genetic admixture wasn’t higher in autistic individuals—it’s these specific rare variants that seem to matter.
🧠 Why This Matters
- Ancient DNA Still Matters: Even after millennia of evolution and selection reducing most harmful Neanderthal variants, some rare ones linger and may subtly influence modern conditions like autism.
- Brain and Developmental Impact: The implicated SNPs are linked to brain-related gene expression and neurodevelopmental traits—particularly epilepsy and language issues.
- Genetic Complexity: Rather than carrying more Neanderthal DNA overall, autistic individuals show enrichment in a select subset of Neanderthal variants.
🌍 A Broader Perspective
Neanderthal contributions to traits like skin color, immunity, and depression are well-known. This study adds a twist: rare Neanderthal variants might underlie part of autism’s genetic complexity. Interestingly, similar patterns of brain connectivity and skull shape—more “Neanderthal-like”—show up in both autistic individuals and those with higher Neanderthal ancestry.
💡 What Comes Next?
- Larger & Diverse Cohorts: To confirm these findings and explore how universal they are.
- Functional Studies: Lab experiments to see how these SNPs affect brain cells.
- Genetic Counseling: Contextualizing how ancient DNA fits into autism risk and its multifactorial causes.
🧬 Conclusion
This intriguing research highlights that some rare Neanderthal-derived gene variants—still with us after millennia—might subtly influence autism risk and related conditions. It opens a fascinating doorway into how ancient human history continues to shape modern minds.
🎙 Words from the Community
On forums like WrongPlanet, co-author Emily Casanova (a neurodivergent researcher) mentioned:
“A subset of Neanderthal DNA appears to be playing a role in autism.”
That nod of recognition from autistic individuals, seeing their own Neanderthal DNA, adds a powerful personal dimension to the study.
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