Down Syndrome
Perspectives on Parenting©
by Nancy Lambert Davenport


Nancy Davenport's Column:
For Richardson News 05-16-99
Copyright Nancy Lambert Davenport 1999


"Gene Therapy"


I challenge the parent who is reading this to think of his or her child's greatest weakness. For some parents it might be poor eye sight, deafness, or a life threatening heart defect. For others it could simply be a child's inability to learn to read, general klutziness, chronic insecurity, or having a differently shaped body. Now my next question is, if you had the means to change this weakness, would you?

At some point probably not to far in the future some of us may have to make such a decision. Each year more and more is being learned about altering genes. We have not arrived there yet, but it will not be long. Some are calling the 1990's the time of the genetic revolution because of all that has been learned and experimented in the treatment of cancer, Alzheimer's, diabetes, and other diseases.

The experimentation that intrigues me the most of course is in the manipulation of genes causing Down syndrome. Thomas J. Torda in his article "The Potential of Gene Therapy for Down Syndrome" in the magazine The Down Syndrome Quarterly, December, 1998, traces the history of this subject from the early 1980's when research projects began popping up all over the world.

American scientists confirmed during that time that people with Down syndrome (who usually have an extra chromosome on their 21st set) have 50% more protein product in their extra genes, but experts couldn't figure out how that causes the harm that it does. The Americans joined Israeli scientists in finding that people with Down syndrome had 50% more h-CuZnSOD, an enzyme present in every cell and necessary for human life. Experiments in which mice were injected with extra doses of h-CuZnSOD produced mice with some symptoms of Down syndrome. It is a well known fact in the scientific world that once something of that sort is isolated, a treatment may not be far behind. In this case the treatment will neutralize or balance the protein levels which in turn might stop some of the symptoms of Down syndrome which develop.

Scientists in France in 1992 achieved a milestone by completing the mapping of that 21st chromosome. Among other things newer projects published in 1994 mapped certain chemicals on the 21st chromosome (neurotransmitter glutamate and acetylcholine) that are heavily studied for improving cognitive function in people with Down syndrome.

In 1994 American scientists developed cellular models in addition to the animal models containing the 50% extra CuZnSOD. That same year Italian scientists assessed the effect of a 90-day treatment (with control groups with and without Down syndrome) of the compound L-acetylcarnitine. The experiment showed a favorable effect only on people with Down syndrome. In 1996 American scientists isolated a gene containing a certain protein product that disrupts brain development. Possibly the most dramatic breakthrough in 1997 was the development of the human artificial chromosome by American scientists. This allowed scientist to be capable of introducing therapeutic genes into a human cell.

It is now possible to design a therapeutic approach to "turn down" a particular gene that is causing harm. Of course problems still surround techniques of administration which involves injecting the chemicals directly into the brain or central nervous system. Surgical techniques also are not without risk and sometimes long term use of a compound is required and the risk increases.

Since June of 1997, over fifty papers have been published all over the world on the genetics of Down syndrome. One experiment in Sweden actually reversed the cognitive decline of rats as they aged. It won't be long - a few years-before practical gene therapy will be available for people with Down syndrome. This of course is a Pandora's box of issues that can explode in our faces. In some of these papers, scientists asked that we be proactive in raising ethical and social issues now, so they can be addressed in a timely fashion.

So what'll it be if you have the opportunity: fix your child through gene therapy or leave him as he was created? You'd better think about it. It may be your call one day.


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Nancy Lambert Davenport
EMAIL: nancdave@swbell.net
URL: http://www.nancyldavenport.com