Children with autism may display repetitive behaviors.
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A drug aimed at eliminating symptoms in people with certain forms of autism is in the early stages of work, and animal studies show promise, researchers report.
In experiments in mice and rats, the drug reversed the effects of a faulty mechanism during birth that might lead the offspring to develop autism, and alleviated the symptoms of autism that certain offspring would normally demonstrate, according to studies published today (Feb. 6) in the journal Science.
The drug, called bumetanide, is a diuretic already approved to treat people with liver and heart disease. It is being tested for safety in children with autism, and researchers will be looking to see if it can achieve similar results in children as seen in the early experiments.
"If you administer a diuretic to the mother 24 hours before delivery, the offspring is, so to speak, cured," study author Yehezkel Ben-Ari, a neurobiologist at the French Institute of Health and Medical Research in Paris, told reporters.
Normally, nerve signaling in a fetus is excited during early development, and then, leading up to and during birth, the hormone oxytocin causes a switch in that excitement. But in certain cases, there appears to be a buildup of chloride, which prevents that switch from happening. This starts a pathway that could lead to autism, the researchers said. [10 Things You Didn't Know About the Brain]
But the drug given in the study appears to stop that problem, Ben-Ari said.
The drug is used to flush water and salt from the body. Because it is generic, Ben-Ari said, there has been difficulty generating funding for research on it. At present, he said, his colleagues are at work on a compound that can be patented to remove that obstacle.
While bumetanide is being tested in children to see if it can eliminate autism symptoms, it's far from clear whether the positive early results in mice and rats will carry over to people.
"I think 90 percent of this paper is really earth-shattering, but there's always the caution of, 'is this going to work in humans, a more advanced mammal?'" said G. Ian Gallicano, a molecular and cell biologist at Georgetown University in Washington DC, who was not involved in the new research.
Mice and rats develop differently from humans in utero, and the first few months of life in humans are comparable, in terms of development, to the last week or so of pregnancy in mice and rats. So it remains to be seen whether giving the drug to infants early in life will match the effects of administering the drug to a pregnant mouse or rat.
Autism cannot be diagnosed prenatally, but certain conditions that often lead to autism, such as fragile X syndrome, can be diagnosed in that early stage. Some of the animals in the study were models of fragile X.
Other animals modeled what happens when a fetus is exposed to a compound in certain drugs a mother might take, including epilepsy medication, which might mean that another drug can be given in combination with it to reduce negative outcomes in children.
"I think you're going to have ample parents wanting to try this, if they know that their child has a genetic disorder that is going to lead to autism," Gallicano told Live Science.
Ben-Ari said the key to successful treatment, as with other therapies, is going to be early intervention. An early change from normal development as shown in this case can result in further problems if left untreated. However, he said, the research may not reach the point where the drug would be given to a pregnant woman rather than the child, after birth.
"What we must do is work in the development and biology earlier so we see, this is insufficient and how we can treat it earlier," he said.