Of the last 100 people tested at Sinai,
Dr. Cash says, three turned up as car-
riers, bearing out the statistics. The
chances of a Jewish Tay-Sachs child
being born is 100 times greater than
in the general population or among
Sephardi Jews. But the experts say
Robin Gold and Dr. Ralph Cash.
these are statistical probabilities —
just numbers.
In reality, the genetic one-in-3600
chance of a Tay-Sachs birth can't be
totally predicted by numbers. Sinai's
Robin Gold says it really is a genetic
crapshoot.
"We all have five or six recessive
genes. This one we know about. With
Tay-Sachs, out of four pregnancies,
one should have the disease. In reali-
ty:' she says, "you could conceive four
times and have four Tay-Sachs babies
— that 25 percent could come up each
time. The normal baby could come on
the fifth try. Or you could have a nor-
mal pregnancy 75 percent of the
time."
The origins of Tay-Sachs are still
noticed a peculiar, cherry-colored red
spot on the retinas of affected infants'
eyes.
Seven years later, New York
neurologist Dr. Bernard Sachs was
the first to describe the changes in
brain cells caused by the disease, as
well as notice it was a familial condi-
tion with ties to the Ashkenazi
Jewish community.
In the 1940s, a German scientist
described the abnormal accumulation
of nerve killers (gangliocides) in the
brain tissue of afflicted children. It
wasn't until 1968 that researchers
isolated the culprit: the lack of the en-
zyme hex-A.
Tay-Sachs is not only deadly but
insidious. An affected child is born
seemingly normal and happy parents
watch the infant progress through the
first five or six months of life. Then
changes start to appear as develop-
ment slows and the baby begins to
regress. A baby may start having
trouble sitting up, or grasping a toy
or bottle since eyesight and muscle
function are beginning to deteriorate.
Tay-Sachs infants also exhibit a
hypersensitivity to sound or an exag-
gerated "startle" reflex. They'll jump
or shudder excessively at loud noises,
says Dr. Cash.
As the first year progresses, Dr.
Cash says the stricken infant's
Bob McKeown
eyesight worsens and involuntary
disease married and conceived a Tay- muslce seizures set in. Bit .bfbit", the
disease robs the child of its senses and
Sachs baby.
The trait, which is most common muscle responses. The child is no
to Eastern European Jews, likely longer able to turn over, to sit, to
started in the Jewish population, says reach out, to crawl, even to swallow.
Eventually, the child becomes
Dr. Mark I. Evans, director of repro-
blind,
deaf, mentally retarded, unable
ductive genetics at Hutzel Hospital.
Evans says the disease remained in to move and totaly unresponsive to
the defined population for a long time the outside world.
They usually sink into a coma,
because of breeding patterns — peo-
ple finding mates only within that says Dr. Cash, as their bodies are
group. "I don't think there's any ques- wracked by uncontrollable seizures
tion that inbreeding in the Pale of and repeated infections. By the time
Settlement caused this trait to be so the disease runs its course, the baby's
head has become enlarged due to the
prevalent;' says Dr. Cash.
Medical science has know for on- accumulation of fat in the brain
ly the last 20 years what actually tissue. Even with the best of care, a
causes Tay-Sachs. The first real clue Tay-Sachs child doesn't live past the
came in 1881, when a British op- age of five.
The double tragedy in all this
thamologist named Dr. Warren Tay
a genetic mystery. "No one knows how
Tay-Sachs started;' says Dr. Cash.
"Possibly some time in the Middle
Ages a genetic mutation may have oc-
curred — and they do occur." The
mutation could have been passed on
until two people who carried the
Free Tay-Sachs screenings
at five locations will' be
held in suburban Detroit
on Jan. 15.
THE DETROIT JEWISH NEWS
23