What’s Tay-Sachs disease?

Tay-Sachs is a genetic disease caused by a missing enzyme. Cynthia Tifft, MD, PhD, director of NIH’s Pediatric Undiagnosed Diseases Program, describes who develops the disease and how it’s diagnosed in infants.

Transcript

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CYNTHIA TIFFT: This is a disease where you're missing an enzyme called beta-hexosaminidase. [MUSIC PLAYING]

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Most people will think of this as common in the Ashkenazi Jewish population. And before the early '70s, it was.

00:21

There were hundreds of babies born every year with infantile Tay-Sachs. Once the defect was found and a physician

00:28

named Mike Kaback began to do carrier screening in the Ashkenazi community, the incidence of Tay-Sachs disease in that community dropped by 90%

00:36

in 10 years. But all of us have a baseline carrier frequency in the general population, in any ethnic group.

00:42

So what we tend to see now are fewer cases, but they're in all different ethnic groups. Well, it presents in an infantile form,

00:49

a juvenile form, and an adult onset form. In the classic infantile form, it's the child who develops to about four months of age.

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The mother comes to the pediatrician and says, you know, I just don't think he's really looking at me. The child gets sent to the ophthalmologist.

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The ophthalmologist looks in the eyes and sees a characteristic trait called a cherry red spot, which indicates that there's been storage of fat sugar molecules

01:13

at the back of the eye. And the child indeed can't see. And that's sort of the key to the diagnosis. And it's essentially a death sentence.

01:21

These children usually are dead by two and a half to four, I'd say. However, as part of the Tay-Sachs Gene Therapy

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Consortium, we have some very promising gene therapy treatment that we're hoping in the next year or so to be able to do, actually intracranial

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gene therapy for these kids. [AUDIO LOGO]