Tay-Sachs Disease

About Tay-Sachs Disease: An End to an Incurable Genetic Disease

Not long ago, Tay-Sachs Disease was relatively common in American Jews. Approximately 1 in 3,600 Jewish babies were born with this devastating genetic disease.  Every baby born with the infantile form of Tay-Sachs dies within a few short years without learning to speak or walk.

Once it became clear that more than 1 in 30 Eastern European Jews were Tay-Sachs carriers, the Jewish community in Baltimore launched the first voluntary program for Tay-Sachs carrier screening in 1971. Similar programs quickly spread to major cities throughout the United States until Tay-Sachs testing became routine for nearly all American Jews of reproductive age.

How many American Jewish babies are born with Tay-Sachs today? Very few.  Carrier screening has almost eliminated Tay-Sachs births in the Ashkenazi Jewish population in the U.S., but there is still no treatment for those who are born with this disease. Although we see fewer Tay-Sachs births among Ashkenazi Jews, the carrier frequency remains the same.  Therefore the risk to a Jewish couple remains. In addition, people of mixed heritage (Jewish/non-Jewish) can also be Tay-Sachs carriers. Risk can only be determined through carrier screening.

Carrier testing gives carrier couples the opportunity to know their risks and have healthy children. Thanks to the availability of prenatal diagnosis and newer reproductive technologies (such as in vitro fertilization with preimplantation genetic diagnosis), thousands of carrier couples have given birth to healthy babies.

The availability of JScreen is a promising step in building upon the initial success of Tay-Sachs screening. The accuracy of JScreen’s test for Tay-Sachs carriers is dependent on the method of testing you choose (genotyping, sequencing, or blood enzyme). See the chart below for a comparison of methods.

Your Options for Tay Sachs carrier screening

Saliva Genotyping

Saliva Sequencing

Blood Enzyme Test

How it Works

“Spot check” for common changes (mutations) in a gene.

Detailed scan of the whole length of a gene.  Sequencing will detect a higher percentage of carriers than genotyping.

Activity of a protein (enzyme) in the blood is measured.

Detection Rate

90%- Ashkenazi Jews

99% in everyone

98% in everyone

50% or less in others

Cost

$99 maximum with private insurance, regardless of coverage amount

$299 maximum with private insurance, regardless of coverage amount

Most private insurances cover the cost of this testing.

$599 without insurance

$999 without insurance

Availability

through JScreen

through JScreen

through your doctor or a community screening event

 

For Ashkenazi Jews, JScreen’s genotyping test will detect 90% of carriers. However, the carrier detection rate for people who have both Jewish and non-Jewish ancestry is much lower. The sequencing test will detect up to 99% of Tay-Sachs carriers in all groups. The JScreen genotyping and sequencing tests are done on saliva. Another test, called the blood enzyme test, is available through your doctor, and can detect up to 98% of Tay-Sachs carriers in all groups. If you have not already had Tay-Sachs enzyme testing, we recommend you also have the blood enzyme test for maximum carrier detection. Tay-Sachs testing is not complete unless JScreen’s DNA tests and enzyme testing are done.  You can also find additional information on how to obtain it here.

While Tay-Sachs may be on the decline in the Jewish community, the battle to end preventable genetic disease is far from over. The Jewish community is at risk for 18 or more other preventable genetic diseases, some of which are even more frequent than Tay-Sachs.

Now it’s up to you to protect your family’s future. Learn your risk for Tay-Sachs and 18 other Jewish genetic diseases – click here to start your testing process now.

Source: Counsyl.