Tay-Sachs Disease (TSDTSD)

BY GREG DEYOUNGBY GREG DEYOUNG

Introduction to Tay-Sachs Disease

There are many genetic diseases in the There are many genetic diseases in the world, some worse than others. Probably world, some worse than others. Probably one of the worst genetic diseases is Tay-one of the worst genetic diseases is Tay-Sachs Disease, or TSD. TSD is a disorder in Sachs Disease, or TSD. TSD is a disorder in which the bearer does not produce a vital which the bearer does not produce a vital enzyme. Without this enzyme, the lipid that enzyme. Without this enzyme, the lipid that the enzyme would usually break down the enzyme would usually break down builds up in the brain and eventually kills builds up in the brain and eventually kills the host.the host.

TSD in Finer Detail

The enzyme missing in TSD patients is The enzyme missing in TSD patients is HexosaminidaseHexosaminidase A (Hex A).A (Hex A).

Lack of Hex A causes buildup of the lipid Lack of Hex A causes buildup of the lipid GM2 Ganglioside in the brain.GM2 Ganglioside in the brain.

It is named for Warren Tay, an It is named for Warren Tay, an ophthalmologist, and Bernard Sachs, a ophthalmologist, and Bernard Sachs, a neurologist.neurologist.

The Lifecycle of a TSD Patient

First, the child is born with Tay-Sachs.First, the child is born with Tay-Sachs. The child appears to be fine and seems to develop The child appears to be fine and seems to develop

normally until about 4 to 6 months after birth.normally until about 4 to 6 months after birth. By then, large amounts of GM2 Ganglioside have By then, large amounts of GM2 Ganglioside have

built up in the brain cells.built up in the brain cells. Soon after, the brain cells get damaged and the Soon after, the brain cells get damaged and the

child becomes mentally retarded.child becomes mentally retarded. Finally, the child’s brain loses all control over the Finally, the child’s brain loses all control over the

body and he or she dies within about 3 years.body and he or she dies within about 3 years.

Treatment for TSDTSD

Currently, Tay-Sachs Disease has no cure Currently, Tay-Sachs Disease has no cure or effective treatments.or effective treatments.

Even with the best medical care, children Even with the best medical care, children with TSD usually die by age 5.with TSD usually die by age 5.

Passing TSD On

Both parents have to Both parents have to be carriers to pass on be carriers to pass on this disorder to their this disorder to their children. children.

Even then, there is Even then, there is only a 25% chance only a 25% chance that one of their that one of their children-to-be will children-to-be will have TSD.have TSD.

Physical Characteristics

This picture shows the “cherry-red” spot on the back of This picture shows the “cherry-red” spot on the back of the retina on someone who has Tay-Sachs.the retina on someone who has Tay-Sachs.

Some More Physical Characteristics

A child with Tay-Sachs looks like he or she A child with Tay-Sachs looks like he or she is just a normal, happy baby for about the is just a normal, happy baby for about the first 5 months of development.first 5 months of development.

Once brain damage begins, the child may Once brain damage begins, the child may stop smiling, crawling, and turning over.stop smiling, crawling, and turning over.

A Look Inside

This is a picture of a Tay-Sachs patient’s brain stem. The This is a picture of a Tay-Sachs patient’s brain stem. The little gray-white blobs are patches of GM2 Ganglioside.little gray-white blobs are patches of GM2 Ganglioside.

Another Look Inside

Here is another look at a patient’s brain stem. This Here is another look at a patient’s brain stem. This time the lipids are stained blue and purple.time the lipids are stained blue and purple.

A Brief Overview

People with Tay-Sachs Disease do not People with Tay-Sachs Disease do not produce the vital enzyme Hexosaminidase produce the vital enzyme Hexosaminidase A, or Hex A.A, or Hex A.

This causes the buildup of the lipid GM2 This causes the buildup of the lipid GM2 Ganglioside in the brain.Ganglioside in the brain.

The buildup of the lipid causes damage to The buildup of the lipid causes damage to the brain cells which eventually kills the the brain cells which eventually kills the bearer of the disease.bearer of the disease.

References

National Institute of Neurological Disorders and National Institute of Neurological Disorders and StrokeStrokehttp://www.ninds.nih.gov/http://www.ninds.nih.gov/

National Tay-Sachs and Allied Diseases National Tay-Sachs and Allied Diseases Association, Inc.Association, Inc.http://www.ntsad.org/http://www.ntsad.org/

Google Image SearchGoogle Image Searchhttp://www.google.com/imageshttp://www.google.com/images

March of Dimes Medical ReferencesMarch of Dimes Medical Referenceshttp://www.marchofdimes.com/http://www.marchofdimes.com/