It’s Time To Find A Treatment For Tay-Sachs Disease
By Norma Kellam
Gene therapy shows promise as a treatment for Tay-Sachs disease. The National Institutes of Health is helping finance the research, which currently involves using modified viruses to carry healthy genes into brain cells of animals. Susan R. Kahn, the executive director of the National Tay-Sachs and Allied Diseases Association, says, “If the NIH-funded project is successful, then a human clinical trial could be started in about 3 years.”
Currently there is no treatment that can delay progression of Tay-Sachs disease, which results from accumulation in the brain of a fatty substance due to the absence or insufficient amount of an enzyme called hexosaminidase-A, or Hex-A for short. This happens when a baby receives a mutant form of a particular gene, also called Hex-A, from each parent. The fatty substance damages the nerve cells.
The infantile type of Tay-Sachs disease is the most common and results from a complete absence of the Hex-A enzyme. Even though the nervous system damage starts prior to birth, babies afflicted with this type appear normal for about the first six months. Then they start regressing in previously achieved developmental milestones. The symptoms progress to blindness, inability to swallow, mental retardation, paralysis, seizures, and lack of response to the environment. Most children with the infantile type die prior to age 5, often by age 3.
In juvenile and Late-Onset Tay-Sachs, the patient’s body produces an insufficient amount of the Hex-A enzyme. Symptoms for the juvenile form usually begin between ages 2 and 5, but some sources say that they can begin as late as age 10. These children usually die by age 15. The most recently discovered and slowest progressing type is Late Onset Tay-Sachs disease. It starts between late childhood and mid 30s.
One in about twenty-seven Ashkenazi Jews is a carrier for Tay-Sachs disease. The incidence of this recessive genetic disease has decreased significantly in the Jewish community due to genetic testing, which became available in 1971. However, non-Jews also get it.
The National Tay-Sachs and Allied Diseases Association (NTSAD www.ntsad.org) funds research and is one of the organizations that helped fund the preliminary research that led up to the NIH grant for gene therapy. “Other than novel approaches to treatment such as gene therapy, we are also able to look at drugs that are already approved for another indication,” Kahn says “For example, there is a phase I clinical trial for pyrimethamine, a compound approved many years ago for malaria. The purpose of the trial is to find out if this drug can help people that are affected by Late Onset Tay-Sachs disease.”
In addition to research, support for families of patients with Tay-Sachs disease is also important. “NTSAD helps each family understand the diagnosis, access local medical resources and connect with other families,” Kahn says. “NTSAD lessens a family’s sense of isolation and desperation through its network of families, its Lifeline newsletter, an Annual Family Conference and compassionate and dedicated staff.”
Even though preventing Tay-Sachs disease is the ideal solution, it is wonderful that effective treatments are on the horizon for those who have the misfortune of having this disease. Kahn says, “There’s more hope than ever before.”
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This article was originally published in the May 2010 issue of Chai-Lights, the newsletter for Pacific Community of Cultural Jews in Orange County, California. Reprinted with permission of the author.
from the February 2011 Edition of the Jewish Magazine