LeVar Baxter shares a tender moment with his 21-year-old son, Khalil, who lives with autism. Khalil, who is non-verbal and cannot live independently, inspired his father’s quest to understand the disorder. “I wanted to know if I had a gene that I’d passed on to Khalil,” Mr. Baxter expressed. (Photo credit: Rachel Wisniewski for The New York Times)
For Bill, hearing his young son diagnosed with autism was like a punch to the gut. The word itself, he recalled, felt like a curse.
While his son, Billy, was indeed slow to develop language and struggled with social interaction, Bill couldn’t shake the heavy questions that came with the diagnosis: What would Billy’s future hold? Would he ever achieve independence, drive a car, find employment, or marry?
The biggest question gnawing at Bill, who requested anonymity to protect his son’s privacy, was ‘Why?’ Why had this beautiful, three-year-old boy been afflicted with such a challenging condition?
“I need to understand what caused this,” Bill shared with Dr. Cathy Lord, a renowned clinical psychologist and autism specialist at UCLA, during a three-hour virtual session. He explained that he had received countless suggestions, particularly from social media, as well as friends and family.
Despite his wife not taking Tylenol, Bill pondered other possibilities: Were red food dyes to blame? Or, as he’d seen on TikTok, could it be a vitamin B6 deficiency?
“Do you think it has anything to do with vaccines?” he asked Dr. Lord, noting that Billy had received all his recommended vaccinations.
These questions are, unfortunately, all too familiar for Dr. Lord.
Professionals working with children on the autism spectrum constantly guide families through a maze of conflicting theories and advice. With the steady increase in autism diagnoses over recent decades and the ongoing intense debate surrounding its causes, they find themselves frequently explaining the limited certainties and vast unknowns of the disorder’s development to distraught parents.
The situation is further complicated by the federal government’s involvement, often disseminating information that contradicts medical consensus, leaving families uncertain whom to trust.
Joseph Buxbaum, a neuroscientist specializing in autism genetics, observes that families he has supported for years are now bewildered. They hear prominent figures like President Trump and Health Secretary Robert F. Kennedy Jr. attribute autism to debunked theories such as vaccines or unproven links to acetaminophen (the active ingredient in Tylenol), creating deep confusion.
“Even those who trust us and understand our strong disagreement are impacted,” stated Dr. Buxbaum, a professor at the Icahn School of Medicine at Mount Sinai. “It’s a truly unsettling period.”
Decades of rigorous scientific investigation overwhelmingly indicate that genetic mutations affecting brain development are a primary cause of autism. Scientists have already pinpointed hundreds of such mutations associated with the condition.
While the scientific community generally agrees that genetics likely interact with environmental factors, extensive research has debunked many common beliefs about autism’s causes and yielded only weak or contradictory evidence for others.
However, Mr. Kennedy, who has controversially labeled the increase in autism cases an “epidemic,” has dismissed genetics research as a “dead end.”
“Genes don’t cause epidemics,” he declared earlier this year. “You need an environmental toxin.”
Like many parents, Bill was well aware of the alarming rise in autism diagnoses, from an estimated 2 to 4 children per 10,000 in 1980 to one in every 31 children today. He candidly asked Dr. Lord if this dramatic increase pointed to an environmental cause.
“Not necessarily,” Dr. Lord responded.
An autism questionnaire rests in a doctor’s office, a symbol of the diagnostic journey. Hundreds of genetic mutations are now linked to autism. While scientists generally accept that environmental factors might play a role, many popular theories have been disproven through research. (Photo credit: Ilana Panich-Linsman for The New York Times)
“Primarily, the numbers have grown because the diagnostic categories themselves have significantly expanded,” she explained.
She elaborated that five decades ago, when her work in autism began, the diagnosis was reserved for only the most severe cases. Today, the autism spectrum encompasses a wide range of individuals, from those who struggle with social cues or friendships to those with profound disabilities.
Dr. Lord also emphasized that greater public awareness, the availability of specialized services for autistic children, and enhanced screening by pediatricians have all contributed significantly to the perceived rise in prevalence.
To ease Bill’s concerns that he or his wife might have inadvertently caused Billy’s autism, Dr. Lord highlighted that autism rates remain consistent across various countries, despite their diverse environmental conditions.
Dr. Lord and her peers, drawing on decades of autism research, consistently inform their patients that the sole established and thoroughly documented cause for autism involves mutations in genes crucial for brain development. However, these genetic mutations currently account for only about 30 percent of cases, predominantly those with the most severe manifestations of the disorder.
The critical role of genes in autism has been recognized since the 1970s. Early studies revealed that autism was significantly more common in identical twins compared to fraternal twins, underscoring a strong genetic component.
A pivotal study published in 2007 demonstrated that children with autism were far more prone to having ‘de novo’ mutations – spontaneous genetic changes not inherited from either parent. These mutations typically arise in sperm or egg cells even before conception.
Subsequent research further uncovered a growing number of both de novo and inherited mutations. Dr. Buxbaum’s latest work, supported by an international consortium and funded by the National Institutes of Health, has identified over 250 distinct genes whose disruption significantly increases the likelihood of profound autism.
Individuals with autism may carry different mutations within the same gene, but critically, each mutation alters the gene’s intended function. This groundbreaking work is slated for presentation at the upcoming American Society of Human Genetics meeting by Dr. Buxbaum’s colleague.
“These are not merely indicators of susceptibility; these are causal mutations,” affirmed Dr. Jonathan Sebat, a geneticist at the University of California, San Diego, and the lead author of the influential 2007 study.
Conversely, research into environmental factors like pollution or specific chemicals has so far yielded only weak evidence of their contribution to autism. While correlations may be observed, concrete causal evidence remains elusive.
In light of these findings, some medical professionals are increasingly recommending genetic testing to parents following an autism diagnosis for their child.
Dr. Audrey Brumback, a pediatric neurologist at the University of Texas at Austin, provides genetic testing to every patient diagnosed with autism. She believes that “finding those answers for families — that in itself is therapeutic,” offering comfort and clarity. (Photo credit: Ilana Panich-Linsman for The New York Times)
Dr. Audrey Brumback, a pediatric neurologist in Austin, Texas, routinely offers genetic testing to families whose children receive an autism diagnosis. She transparently informs parents that a relevant genetic mutation is identified in only one out of four cases.
“Virtually every mother I see blames herself,” Dr. Brumback observed, citing common maternal concerns like having a small amount of red wine during pregnancy, taking Tylenol for a headache, or enduring stressful experiences.
Dr. Brumback clarifies that the probability of discovering a de novo mutation increases when a patient presents with severe autism alongside co-occurring conditions such as epilepsy, movement disorders, or intellectual disabilities. For those with initial negative results, she often advises future retesting, as scientific understanding of genetic mutations continues to evolve.
“Providing these answers to families is inherently therapeutic,” Dr. Brumback asserted. She noted that a genetic diagnosis can also reveal targeted interventions for children, shifting parents from “consuming all of Facebook” to focusing on evidence-based strategies based on the root cause.
For parents who have spent years agonizing over the cause of their child’s autism, a confirmed genetic mutation can bring profound solace.
LeVar Baxter, a police officer from Gilbertsville, Pennsylvania, experienced this very relief.
Early in his life, Khalil met developmental milestones ahead of schedule. Mr. Baxter and his wife were confident he’d be walking by nine months old.
However, at around four months, Khalil regressed, losing his acquired developmental skills. Now 21, he is a cheerful young man who, despite daily smiles, remains non-verbal and requires full-time care.
Persistent worries plagued Mr. Baxter. Had he or his wife somehow caused Khalil’s autism? Was it an environmental factor, or perhaps the vaccines his infant son received?
“We understand allergies to milk or peanuts,” he mused, “so is it possible some individuals are allergic to vaccines?”
At their Gilbertsville, PA home, Mr. Baxter lovingly spoon-feeds Khalil an after-school snack on the couch, a daily routine reflecting his ongoing care. (Photo credit: Rachel Wisniewski for The New York Times)
Upon learning that the Simons Foundation was seeking families for genetic research, Mr. Baxter eagerly volunteered.
“I needed to know if I had passed on a specific gene to Khalil,” he explained.
A decade passed. Then, last year, a letter arrived from the Simons Foundation: they had identified a gene.
The news, Mr. Baxter admitted, “reset my anxiety,” making him hesitant to delve further.
He discovered the mutation was a rare one, CLCN4, linked to neurological development and speech capabilities.
“I was stunned,” Mr. Baxter recounted. “My immediate question was, ‘Did I do anything wrong, or could I have acted differently?’”
The counselor reassured him, offering an analogy: out of a million cars produced annually, one is bound to have engine issues from day one.
“That lifted an enormous weight off my shoulders,” Mr. Baxter confessed. “For years, I had carried the guilt, blaming myself for allowing him to be vaccinated.”
Inspired by Dr. Lord’s advice, Bill, Billy’s father, has also opted for genetic testing for his son, understanding that a discovery may not change their path but can offer understanding.
Dr. Lord shared reassuring news that Billy does not exhibit severe autism, yet also tempered expectations, admitting she couldn’t predict his future development.
Bill, however, remained optimistic.
“My wife calls me a helicopter dad,” he chuckled, “but no matter what, I’ll always be there for him.”
Mr. Baxter shares a loving kiss with Khalil, football in hand, in their yard, a testament to their enduring bond. (Photo credit: Rachel Wisniewski for The New York Times)