Down’s Syndrome cure – new research shows promise
There are 6 million people in the world with Down’s syndrome. 60,000 of those are in the UK, with 750 babies born each year with the condition. Now imagine the possibility of being able to cure those babies as soon as they are born – with only one injection.
There isn’t currently a cure for Down’s syndrome, however; researchers at John Hopkins University of Medicine and the National Institutes of Health published a study with the exciting results.
Down’s syndrome is a genetic condition caused by an extra chromosome which can cause learning difficulties and a variety of other health issues including low birth weight, poor vision, poor hearing, and reduced muscle tone.
The part of the brain in charge of motor control, the cerebellum tends to be significantly smaller than in a healthy person. Changes to the hippocampus which handles learning and memory are also common.
The research led by Dr Roger Reeves at John Hopkins University, genetically engineered mice to have many similar aspects to the human Down’s syndrome.
The mice exhibited some of the symptoms from Down’s syndrome, including the motor control, learning and memory difficulties. Although not exactly the same as in a human, the effect on development of the mice was very similar.
Dr Reeves and his team treated the genetically engineered newborn mice with a small molecule called the “Sonic Hedgehog pathway agonist”, known to them as “SAG”. With only one injection given to the mice shortly after they were born, the scientists noted improvements to some of the symptoms.
SAG stimulates something called the “Sonic Hedgehog pathway” which transmits information to undeveloped cells in an embryo so that they develop properly.
The scientists found that as long as they administered SAG on the day the mice were born, the cerebellums developed almost to full size. They also found that the mice had improved learning abilities and memory.
In tests, where the mice swam through a water maze to find a platform, it was found that the mice who had been given the SAG injection performed just as well as a mouse without the condition.
The researchers say the results tell them just how important the development of the cerebellum is and that they have a direction to focus on to develop treatments that could help people with Down’s syndrome.
Dr Reeves said: “It worked beautifully. Most people with Down’s syndrome have a cerebellum that’s about 60 per cent of the normal size… We were able to completely normalise growth of the cerebellum through adulthood with that single injection.”
The study of SAG’s effect on mice is still in the very early stages, although it seems to have a positive effect on some of the symptoms, others don’t seem to have been affected at all. It is still far too early to tell whether or not it could be developed into a cure for humans, and the researchers don’t even know if it would be possible. Manipulating the Sonic Hedgehog pathway could have repercussions for the rest of the body, maybe even raising the risk of cancer. But again, as it is too early to tell, they don’t know just how positive the development could be either. As Dr Reeves said: “Multiple approaches will be needed.”