Progress on ‘reversing’ Down’s syndrome

Down Syndrome Ireland has said the majority of parents would warmly welcome any research which could eventually reverse the condition in newborns.

Their comments come as US researchers discovered a way to halt the progress of the condition in newborn mice by injecting them with a compound that causes the cerebellum part of their brain to grow at a normal rate through adulthood.

Most people with Down’s syndrome have a cerebellum that is only 60% of the normal size.

The injection also led to unexpected benefits in learning and memory, normally handled by a different part of the brain known as the hippocampus.

The study, published in the Science Translational Medicine journal, offers no direct link to a treatment for humans but scientists are hopeful it may offer a path towards breakthroughs.

The team at Johns Hopkins University of Medicine, in Baltimore, found that after an injection at birth, the rodents were able to function as well as mice without learning disabilities in behavioural tests.

The compound contains a gene which provides instructions for making a protein called sonic hedgehog, which is essential for normal brain development.

There is currently no cure for Down’s syndrome, which is caused by the presence of an additional chromosome. But, adjusting the treatment for human use would be complicated, as altering the growth of the brain could lead to unintended consequences, such as triggering cancer.

Chief executive of Down Syndrome Ireland Pat Clarke said parent groups have been aware since the Down Syndrome World Congress in Dublin four years ago that such research was under way.

“The research doesn’t make me feel uncomfortable in the least, as the father of a 32-year-old son with Down’s syndrome. I think parents would like to see any progress for their children.

“This is a complex disorder, however, and aside from the intellectual disabilities that it causes, there are also the heart, thyroid, blood condition and speech and language problems that accompany it. These would all have to be factored into any kind of ‘cure’. We are at least 10 years away from any of these advances being used on newborn babies, so I think for all the parents of children with Down’s syndrome out there, they will be focussing on their children as they are and doing all they can to allow them to reach their full potential.”

His words were echoed by Professor Roger Reeves, who headed up the study and has dedicated his life to studying Down’s syndrome.

“People with Down’s syndrome have extra copies of the more than 300 genes housed on that extra chromosome, which leads to intellectual disabilities, distinctive facial features and sometimes heart problems and other health effects. Since the condition involves so many genes, developing treatments for it is a formidable challenge.”