Scientists Discover a Drug That May Be Able Help Down's Syndrome Sufferers

The team looked at a drug that was once tested in the 1950s as a possible treatment for Epilepsy. According to the Journal Nature Neuroscience, a once-a-day treatment over a course of two weeks helped mice to overcome problems linked to Down's Syndrome. However, UK experts stated that clinical trials would be required to find out what the impact of the drug would be on humans.

Down's Syndrome, also known as Down Syndrome, is one of the most common causes of learning difficulties. It is caused by the presence of an extra copy of a chromosome, known as chromosome 21. This results in trisomy 21. According to Elizabeth Riscoe, from the University of Colorado, the trisomy is due to a "nondisjunction occurring randomly during meiosis (gamete formation)". Down's Syndrome affects 1 out of every 900 births in America.

Researchers in this study are looking into the possibility that the brains of Down's Syndrome patients are strongly affected by a chemical called GABA. This slows down the nerve cell activity in the brain. They explored the drug pentylenetetrazole, also known as PTZ, and discovered that it works by blocking the action of GABA.

The team of researchers administered daily doses of PTZ to mice who were bred to have many of the same genetic differences that result in Down's Syndrome and then made them perform a maze task. Compared to the average mouse, these mice tended to explore the maze in a rather random way. However, after 17 weeks of treatment, these mice began to explore the maze in much the same way as "normal" mice. Further tests were carried out and these revealed that the mice continued to act in a normal manner up to two months after the PTZ drug was stopped.

Professor Craig Garner, who was responsible for leading the research stated: "This treatment has remarkable potential. So many other drugs have been tried that had no effect at all. Our findings clearly open a new avenue for considering how cognitive dysfunction in individuals with Down syndrome might be treated."

Researchers are now considering the possibility of pushing ahead towards clinical trials to see whether the drug will have the same effect on humans, as it did on the mice. At present, PTZ has not been approved for human usage. High doses are known to cause seizures. The chief executive of the Down's Syndrome Association, Carol Boys, welcomed the research, but went on to state that: "We must remember that this research has been conducted with mouse models.
At this stage the compound PTZ is not approved for human use and until extensive further clinical trials with real people have been conducted it will be impossible to predict how this drug might affect the lives and abilities of people with Down's syndrome."

This certainly is a remarkable discovery, but it is not a cure for Down's Syndrome. The research is still in its infancy and many more tests will need to be carried out before it is decided whether or not PTZ is a safe and effective drug for use in human patients.

Source:

http://news.bbc.co.uk/2/hi/health/6396473.stm
http://www.altonweb.com/cs/downsyndrome/index.htm?page=riscoe.html