Updated on 16 July 2013
The spokesperson added that the testing will initially involve 10 hospitals across Japan, with many people in the affected age group. The programme will continue for up to four years.
The drug is not intended to treat the underlying condition, rather it is hoped it will target some of the symptoms, he further said.
Around one in every 830 newborns in the US has Down's syndrome, according to the National Institutes of Health. This equates to about 250,000 people in the US population.