Jewish World Review August 31, 2000 / 30 Menachem-Av, 5760

Cindy Sher

Late Onset Tay-Sachs: Foundation promotes understanding of rare, elusive disease

http://www.jewishworldreview.com --- Shirley Webb quit teaching elementary school because she couldn't stop her hand from falling off the chalkboard. Even as a little girl, she felt clumsy.

"Ever since I can remember, I've had a hand tremor and I was poorly coordinated," Webb said. "I remember the children in grammar school yelling, 'Oh, you run funny.'"

She couldn't jump or ride a bike either and she needed a banister to climb the stairs. Over the years, her hand tremor worsened, making drinking and eating a challenge. And her leg muscles gradually deteriorated even more. Webb knew there was something wrong with her, but she didn't know what. After 44 years of misdiagnosis and mystery, she was re-diagnosed with late onset Tay-Sachs (LOTS) in 1982. One of less than 100 reported cases, Webb, at age 63, is believed to be the second-oldest person with the disease. Webb is vice president of the Late Onset Tay-Sachs Foundation.

Physicians first noticed the rare genetic neuromuscular disorder in patients in the late 1970s. Like Webb, most identified LOTS carriers and sufferers come from Ashkenazi Jewish extraction, but non-Jewish groups are not immune to the condition. The disease strikes one in 67,000 Jews in the United States and one out of 14,000 Israeli Jews. French Canadians are second most vulnerable to the disease.

LOTS is caused by a deficiency of the enzyme Hexosaminidase A (Hex A), according to Marc Fishbein, husband of an affected person and president of the LOTS Foundation. In healthy people, Hex A breaks down lipids and other fatty substances in the nerve cells of the brain. LOTS sufferers have a small amount of Hex A, but not enough to function properly. Very slowly, the lipids accumulate, gradually breaking down the central nervous system. LOTS is a rare variant of the better-known infantile Tay-Sachs.

"The difference between infantile and adult Tay-Sachs diseases is that there is essentially no Hex A activity left in infantile patients, but there is close to 10 percent residual activity left in adult patients," neurologist William Johnson wrote for the LOTS Foundation. (Juvenile Tay-Sachs is another form of the disease and the most rare of the three types.)

Because Tay-Sachs babies have no Hex A, they cannot carry out normal motor life functions like breathing and swallowing. Tay-Sachs destroys their central nervous system, leading to death in early childhood. LOTS patients, on the other hand, live a normal life span because the disease progresses so slowly.

Since Tay-Sachs genes are recessive, a person cannot inherit the genetic defect unless both parents are carriers. If both parents carry the Tay-Sachs gene, there is still only a one in four chance of having an affected child with each pregnancy. Although a child can become a carrier for the gene even if only one parent is a carrier, the child will not suffer from any Tay-Sachs disorder.

LOTS signs usually appear between adolescence and the mid-30s, but victims often see harbingers of the illness early on, similar to Webb's experience. It's hard to pinpoint the exact onset of the disease, given its progressive nature.

Symptoms may include clumsiness, hand tremors, muscle weakness, speech impediments, swallowing difficulties, gait and balance problems, and seizures. Some LOTS patients suffer from memory loss and comprehension difficulty. Psychiatric problems such as severe depression or mood disturbances occur in 40 percent of LOTS cases.

There is no treatment for the disease itself, but patients currently use various treatments to control its symptoms. And a cure may not be so far off. At Harvard Medical School Children's Hospital in Boston, Dr. Evan Snyder has halted Tay-Sachs disease in mice. Through the use of neural stem cells, the neurologist has discovered a way to supply a missing gene to the brain, reversing genetic diseases like Tay-Sachs.

Talk of a cure is encouraging to LOTS patients and their families, but some remain wary. "We're cautiously optimistic," said Judy Kaplan, executive vice president of the LOTS Foundation and mother of an affected daughter. "We've lived with it for so long that optimism is very difficult. But we're not as pessimistic as we used to be."

A blood test can identify both disease carriers and people affected with the condition. Kaplan urges all couples-even those planning to intermarry-to get tested before marriage.

These days, Webb deals with her condition as best she can. Restricted to a wheel chair, she needs help with household chores. But one activity she manages by herself is calling to check in with everyone she knows affected with the disease, a hefty list of around 50 people, twice a year. Webb feels a unique connection with fellow LOTS sufferers. "It's just like you'd call a member of your family."

The LOTS Foundation, a Pennsylvania-based volunteer organization, began six years ago to promote LOTS awareness. For more information, call the foundation at (800) 672-2022 or log onto its website by clicking here.

Cindy Sher is a staff writer for JUF News. Contact the author or the magazine by either clicking here or calling (312) 444-2853.