New to the idea of Down syndrome research and treatment? Or just want to brush up on your knowledge? Here are some common questions we hear. This is part 1, in which we take a quick look at DS cognition research in general.
What is Down syndrome?
Down syndrome is a genetic condition caused by an error in cell division that occurs at conception. It entails an extra copy of the 21st chromosome; a person with DS has 47 chromosomes instead of the usual 46. This extra genetic material disrupts the normal course of fetal development, resulting in certain common physical signs and other less predictable traits: the extra chromosome can cause a wide range of health problems, and produces varying degrees of intellectual disability.
For most people with Down syndrome, cognitive impairment falls in the mild to moderate range, and they experience speech and language difficulties. This particular aspect of Down syndrome — cognition, the process of acquiring knowledge — is what our research addresses.
Isn’t Down syndrome too complex to treat?
Many of the physical problems associated with DS are already being treated; heart defects can be repaired surgically, for example, and poor vision and hearing can be improved through fairly simple means. Treating the cognitive effects of DS — reducing the severity of impairment in an individual and improving overall function — is admittedly a more complicated proposition.
Still, we believe it can happen. Over the last decade, scientists have made exciting strides toward that goal. The DS cognition research we promote is currently following two promising avenues of inquiry:
The genetics-based approach.We now understand how specific genes correspond to specific abnormalities in brain structure and function. Although each chromosome carries hundreds of genes, researchers suspect there may be only a handful of those that significantly affect cognitive ability. Once researchers have isolated the effects of that particular handful, we can begin to determine how the expression of those genes causes problems with cognition — an essential step in developing effective therapies.
The mouse model approach. To understand the physical differences of the brain affected by DS and the resulting functional impact, researchers look to the mouse. In general terms, the process involves examining mice with Down syndrome — yes, really — to identify which specific mechanisms in the brain are responsible for cognitive impairment; as these mechanisms are established, scientists can begin to pursue appropriate treatments.
The diligent work of these researchers is already proving that Down syndrome isn’t too complex to understand. Based on their results so far, we predict that it’s not too complex to treat, either.
So does treating DS mean a cure?
No, once a child with DS is conceived, the extra chromosome is there to stay. Still, eventually we may able to reverse or improve the cognitive deficiency it causes. No one can say for sure how much of an improvement we can hope for, but even a modest increase of 15 IQ points could have a profound impact on the life of someone with Down syndrome. For those who are mildly or moderately impaired, meaning the majority, those extra 15 points could mean greater independence and fulfillment in school and in the workplace. We’re not proposing a cure for Down syndrome. We’re working toward the promise of greater opportunity — and a more secure future — for the people who have it.
In part 2 we’ll talk about our organization’s specific research objectives. In the meantime, we’d be happy to take on any questions you have about DS research and treatment — do let us know what you’d like to know, and join us again next week as we continue the conversation.
Image adapted from the Genome Management Information System, Oak Ridge National Laboratory.