Researchers have identified over 800 genes associated with autism spectrum disorder, a complexity that complicates the development of a universal medication.

However, a breakthrough might be on the horizon for some individuals, thanks to a team at Yale University who believe they have unlocked a potential treatment using an existing prescription drug.

The study involved testing 774 drugs approved by the FDA to observe their effects on zebrafish genetically engineered to exhibit autism-like traits.

The findings were promising: one particular drug, levocarnitine—marketed as Carnitor—significantly improved the fish’s ability to perceive and interact with their surroundings, areas often challenging for those with autism.

This medication, priced at 44 cents per tablet and available by prescription, is traditionally used to address carnitine deficiency, a rare genetic disorder that leads to insufficient levels of carnitine, an essential compound for cellular energy. It’s also popular among athletes seeking to enhance performance by boosting cellular energy. Annually, nearly 400,000 levocarnitine prescriptions are issued across the country.

The precise mechanism by which the drug alleviates autism symptoms remains unclear, but researchers speculate that it may enhance energy production in specific brain regions that are underactive in some individuals with autism, such as those involved in language and emotional processing.

Dr Ellen Hoffman, a neurobiologist who led the research, said: ‘Because autism spectrum disorder is highly clinically and genetically [varied], it is challenging to identify drug candidates.

‘Our study highlights the importance of [analyzing] autism risk genes to identify potential [treatments].’

Scientists behind a new study say they may have found a new drug that could treat certain behaviors of autism (stock image)

The scientists said the results were promising, although they urged patients not to purchase and start taking the drug for autism. They noted the results needed to be confirmed in human trials, which can take several years.

In their study, the zebrafish had their DNA edited to carry two specific genes linked to autism — SCN2A and DYRK1A. Studies suggest only up to 0.5 percent of autism sufferers carry at least one of these genes, an important limitation of the research.

The findings come as autism rates have surged in America, with an estimated one in 31 children now diagnosed with the condition compared to one in 150 in 2000. Overall, 5.4 million Americans are estimated to be living with autism.

It isn’t clear what’s behind the explosion in cases, but experts have blamed increased awareness and the expansion of the definition of the condition to include other milder cases of communication problems.

There is currently no cure for autism, but scientists are constantly working on new treatments to alleviate severe symptoms such as being nonverbal. 

Levocarnitine is primarily used to treat the disorder carnitine deficiency, which affects anywhere from one in 40,000 to one in 140,000 newborns in the US.

Carnitine is a natural substance that the body uses to process fats and produce energy, which is normally acquired from consuming foods. In carnitine deficiency, sufferers have a mutation that leaves them struggling to transport the substance into cells.

In the study, published in the Proceedings of the National Academy of Sciences, the team first exposed non-gene-edited zebrafish — which share 70 percent of their DNA with humans — to the FDA-approved drugs.

Other drugs that were tested include estropipate, sold under the brand name Ogen, a prescription drug used to treat menopause symptoms, and paclitaxel, also known as Taxol, which is a cancer medication.

After observing their response, scientists identified 520 drugs that were not toxic to the fish and had a significant impact on their behavior.

The fish were then gene-edited to add DNA linked to autism.

At the larval stage, between 24 and 72 hours old, the gene-edited fish were then re-exposed to these drugs in the lab. Scientists monitored the fish for their reaction to changes in the environment while being exposed to the drug.

Human stem cells were then exposed to the drugs to confirm that they were safe to use in humans.

The team found levocarnitine had the strongest ability to suppress both DNA mutations. 

The researchers have published their results in an online database, and hope that the data will be used to investigate new treatments for autism. 

They are now considering human clinical trials testing levocarnitine. 

Asked whether patients should start taking levocarnitine to treat autism, the researchers said: ‘Not yet.

‘While the results in fish and human stem cells are incredibly promising, this study provides the “groundwork” for clinical trials.’