Genetics and Heritability of Autism

Autism isn't new, but our understanding of it has changed dramatically.

It's now recognized as a broad neurodevelopmental spectrum that shapes how millions of people perceive, process, and interact with the world.

In this episode, we explore what autism is AND isn't, from its earliest signs in infancy to its deep genetic roots, and why misinformation about it continues to spread.

We speak with three remarkable experts leading the field in early detection, genetics, and public education:

DR. AMI KLIN, PhD, Director of the Marcus Autism Center at Emory University and a pioneer in early autism research, whose work shows autism can be identified in babies as young as two months old.

DR. JOSEPH BUXBAUM, PhD, Director of the Seaver Autism Center at Mount Sinai and a global leader in autism genetics, uncovering hundreds of genes linked to the condition.

DR. ANDREA LOVE, immunologist, microbiologist, and founder of ImmunoLogic, known for her clear, evidence-based communication about vaccines, immunity, and autism myths.

Together, we discuss:

• What autism really is, and how the definitions have evolved • How it develops in infancy (and why early diagnosis can be so critical) • The powerful genetic evidence behind autism • The persistence of vaccine myths, and how misinformation spreads • How technology like eye-tracking can detect autism early • The rise of "profound autism" and what it means for families • The future of genetics-based treatments and therapy

Whether you're autistic yourself, a parent navigating a new diagnosis, or simply seeking understanding, we're thrilled to share this extensive, in-depth episode with you.

This is... Your Brain On Autism.

SUPPORTED BY: the 2026 NEURO World Retreat. A 5-day journey through science, nature, and community, on the California coastline: https://www.neuroworldretreat.com/

'Your Brain On' is hosted by neurologists, scientists, and public health advocates Ayesha and Dean Sherzai.

'Your Brain On... Autism' • SEASON 6 • EPISODE 1

LINKS

Dr. Ami Klin at Emory University: https://ctsn.emory.edu/faculty/klin-ami.html

Dr. Ami Klin at Marcus Autism Center: https://www.marcus.org/about-marcus-autism-center/meet-our-leadership/ami-klin

Dr. Joseph Buxbaum at Mount Sinai: https://profiles.icahn.mssm.edu/joseph-d-buxbaum

Dr. Andrea Love's website: https://www.immunologic.org/

Dr. Andrea Love on Instagram: https://www.instagram.com/dr.andrealove

REFERENCES

Autism Spectrum Disorder: A Review. JAMA, 2023. https://jamanetwork.com/journals/jama/article-abstract/2800182 Is There a Bias Towards Males in the Diagnosis of Autism? A Systematic Review and Meta-Analysis. https://link.springer.com/article/10.1007/s11065-023-09630-2 Acetaminophen Use During Pregnancy and Children's Risk of Autism, ADHD, and Intellectual Disability. https://pubmed.ncbi.nlm.nih.gov/38592388/ Eye-Tracking–Based Measurement of Social Visual Engagement Compared With Expert Clinical Diagnosis of Autism. https://jamanetwork.com/journals/jama/fullarticle/2808996 Rare coding variation provides insight into the genetic architecture and phenotypic context of autism. https://www.nature.com/articles/s41588-022-01104-0 Rare coding variation illuminates the allelic architecture, risk genes, cellular expression patterns, and phenotypic context of autism. https://www.medrxiv.org/content/10.1101/2021.12.20.21267194v1 Andrew Wakefield and the fabricated history of the alleged vaccine-autism link. https://geneticliteracyproject.org/2024/04/29/andrew-wakefield-and-the-fabricated-history-of-the-alleged-vaccine-autism-link/

VACCINES & AUTISM

1. Major Cohort Studies

Hviid et al., 2019 – Annals of Internal Medicine A nationwide study of 657,461 Danish children found no increased risk of autism in vaccinated children compared to unvaccinated peers — even among those with risk factors such as a sibling with autism. Ann Intern Med. 2019;170(8):513–520

Madsen et al., 2002 – New England Journal of Medicine In 537,303 Danish children, researchers found no difference in autism rates between vaccinated and unvaccinated groups, and no relationship with age, timing, or date of vaccination. NEJM. 2002;347:1477–1482

Jain et al., 2015 – Journal of the American Medical Association (JAMA) A U.S. cohort of 95,727 children — including those with siblings with autism — showed no link between MMR vaccination and autism risk, even in genetically predisposed children. JAMA. 2015;313(15):1534–1540

Madsen et al., 2003 – JAMA A study of 467,450 Danish children found no relationship between thimerosal-containing vaccines and autism. JAMA. 2003;290(13):1763–1766

DeStefano et al., 2022 – Vaccine A retrospective cohort of over 500,000 U.S. children with ASD found no increase in adverse events or worsening of autism-related symptoms following vaccination. Vaccine. 2022;40(16):2391–2398

2. Population-Level Epidemiologic Evidence

Taylor et al., 1999 – The Lancet One of the earliest large epidemiological studies found autism prevalence was the same in vaccinated and unvaccinated children, and the age of onset was unrelated to the timing of MMR vaccination. Read: Lancet. 1999;353(9169):2026–2029

Institute of Medicine (U.S.) Immunization Safety Review, 2011 A global review of studies from the U.S., Denmark, Sweden, and the U.K. concluded there is no causal relationship between vaccination status and autism, and no plausible biological mechanism linking vaccines (including thimerosal) to ASD. Read: National Academies Press / PubMed 20669467

3. Systematic Reviews and Meta-Analyses

Taylor et al., 2014 – Vaccine A comprehensive meta-analysis of 10 studies including over 1.2 million children found no association between vaccination and autism or ASD. Vaccine. 2014;32(29):3623–3629

Maglione et al., 2014 – Pediatrics Review of 67 high-quality studies covering the full U.S. immunization schedule concluded that vaccines are safe, adverse events are rare, and there is no link to autism, type 1 diabetes, or other chronic conditions. Pediatrics. 2014;134(2):325–337

Parker et al., 2004 – Pediatrics Systematic review of 10 primary studies examining thimerosal exposure found no relationship between vaccines and ASD. Authors noted that studies showing an association were methodologically flawed or biased, while robust studies consistently showed safety. Pediatrics. 2004;113(6):1904–1910

Offit & Hackett, 2003 – Clinical Infectious Diseases Review of immunology and epidemiology concluded that claims that vaccines "overwhelm" or "damage" the immune system are not biologically plausible based on how the immune system actually functions. Clin Infect Dis. 2003;46(9):1450–1456