Scientists discover autism may have been passed on through Neanderthal genes

Inbreeding between Neanderthals and humans may have given rise to autism in today’s society, a new study shows.

Researchers have found that certain genetic variations traced back to Neanderthals are more common in autistic individuals than in people without the disorder.

The DNA variants were also linked to traits such as intellectual disability, language delay and language regression, suggesting that they also affect a person with multiple diseases or conditions.

Their findings could help scientists understand the complex nature of autism and how the mixing of archaic and modern human DNA has shaped today’s modern health problems.

Humans coexisted with Neanderthals for nearly 3,000 years, and interbreeding between the two species resulted in higher levels of the rare genetic variants that occur in about one percent of the population today.

The studypublished in Molecular Psychiatry, marked the first time researchers have provided strong evidence that a subset of Neanderthal DNA led to autism – for which there is no known cause.

‘In our research we discovered that autistic people have rarer Neanderthal variants on averagenot that they have more Neanderthal DNA in general,” Emily Casanova, lead author of the study and assistant professor of neuroscience at Loyola University New Orleans, told me. PsyPost.

‘That means that while not all Neanderthal DNA necessarily influences susceptibility to autism, a subset does.’

Researchers from Clemson and Loyola University used exome sequencing – a type of genetic analysis – to understand the cause of symptoms or diseases.

They compared autistic individuals with their unaffected siblings.

The study found that a person’s cultural background influenced whether he or she had the rare DNA, with it being more common among three ethnic groups: black non-Hispanic, white Hispanic and white non-Hispanic .

The team identified 25 rare and common Neanderthal genes, called single nucleotide polymorphisms (SNPs), that were significantly more common in people with autism.

“These results strongly suggest that Neanderthal-derived DNA plays an important role in susceptibility to autism in large populations in the United States,” the study said.

“I know a lot of people will read the headline and immediately assume that autistic people have more Neanderthal DNA than non-autistic people – that they are somehow ‘more Neanderthal,’” Casanova told PsyPost, and added, “I wouldn’t say I blame them for this assumption.”

However, she clarified, “Our results are a little more nuanced than ‘autistic people are just more Neanderthals.’

The rare DNA was most common in three ethnic groups, including black non-Hispanic people, white Hispanic people and white non-Hispanic people, and was significantly more common in those who also suffered from epilepsy and had a family history of autism.

“I was quite surprised that many of the Neanderthal-derived variants we found that were linked to autism differed dramatically by ethnic group,” Casanova said.

“To me, this suggests that our tendency to ‘gloss over’ genetics and ignore variants that are not involved in all genetic backgrounds means that we are missing many important genetic factors,” she added.

Additional research needs to be done to look at the entire genome to confirm that Neanderthal DNA undoubtedly influences the development of autism.

The team also plans to look at the Denisovan genome, which comes from the Altai Neanderthals who lived in Siberia, to see if they could replicate the results for autistic people of Asian and Native American ancestry.

Neanderthals, a close relative of modern humans, went extinct 40,000 years ago

Neanderthals were a close human ancestor who mysteriously went extinct about 40,000 years ago.

The species lived in Africa for millennia with early humans before moving to Europe about 300,000 years ago.

They were later joined by humans, entering Eurasia about 48,000 years ago.

Neanderthals were a cousin of humans, but not a direct ancestor (the two species split from a common ancestor) who became extinct about 50,000 years ago. The photo shows a Neanderthal museum exhibit

These were the original ‘cavemen’, who were historically thought to be stupid and brutal compared to modern humans.

However, in recent years, and especially in the past decade, it has become increasingly clear that we are failing Neanderthals.

A growing body of evidence points to a more sophisticated and versatile species of ‘caveman’ than anyone ever thought possible.

It now seems likely that Neanderthals would have narrated, buried, painted, and even interbred with their dead.

They used body art such as pigments and beads, and they were the very first artists, with Neanderthal cave art (and symbolism) in Spain apparently predating the earliest modern human art by some 20,000 years.

It is believed that they hunted on land and did some fishing. However, they became extinct about 40,000 years ago after the success of Homo sapiens in Europe.