A team of Kyoto University researchers announced Tuesday that they have discovered a chemical compound that may help nerve cells grow in the brains of people with Down syndrome and improve their learning ability.

The findings could lead to the development of drugs to treat Down syndrome in fetuses, they said, adding that it could also lead to treatment for other cerebral nerve illnesses, including Alzheimer’s and Parkinson’s diseases.

Down syndrome, caused in most cases by an extra copy of chromosome 21, genetically impairs intellectual ability. At present, prenatal diagnosis is possible. But there are no therapies available now for normalizing brain functions.

Masatoshi Hagiwara, professor at Kyoto University, and colleagues identified the compound, called altered generation of neurons, or ALGERNON, after screening a total of 717 candidate compounds.

Re-creating cells of people with Down syndrome from induced pluripotent stem (iPS) cells, the researchers then confirmed that the compound inhibited the target gene from restricting proliferation of neural stem cells, which become nerve cells, and increased the number of newborn neurons to almost the level without the syndrome.

The oral administration of the compound to pregnant mice with the syndrome for five days also normalized the formation of the cerebral cortex in embryos and prevented the development of abnormal behavior in offspring, the researchers said.

“The purpose of the research was to find a compound that can regenerate nerve cells,” Hagiwara said, adding that his team will strive to create drugs to treat brain infarctions and other disorders being suffered by a number of people with Down syndrome.

But Kunio Tamai, who heads the Japan Down Syndrome Society, was cautious about the development.

“The latest research may allow a third person to change the physical characteristics inherited from their parents,” Tamai said. “It needs debate not only from a medical perspective but also from an ethical perspective.”

Tamai added that he wants researchers to release more information.

Details of the study will be published online by the U.S. scientific journal Proceedings of the National Academy of Sciences by Friday.