Ashkenazi Jewish Genetic Diseases

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Ashkenazi Jewish Genetic Diseases

What Are Ashkenazi Jewish Genetic Diseases?

"Ashkenazi" means that a person's Jewish ancestors originally came from central or eastern Europe (for example Russia, Poland, Germany, Hungary, and Lithuania). Most Jewish people in North America are Ashkenazi.

A group of genetic diseases is unusually common in people who have Ashkenazi Jewish ancestors. Genetic testing is available for at least 16 of these conditions to find out if you have a higher chance to pass it on to a child. Most but not all of these diseases are serious, affect children, and don't have very good treatments.

You can learn more about each of these conditions by clicking on the disease name.

People from other ethnic groups may also need to consider testing for some of these conditions. For instance, cystic fibrosis carrier testing is offered to most women who are pregnant or planning pregnancy, regardless of ethnicity. Tay-Sachs carrier testing should also be considered for people of French-Canadian, Cajun, and sometimes Irish ancestry. These reasons for testing are not discussed here. If you have questions about testing, you should talk to your doctor or a genetic counselor about your circumstances.

Next: Genetics of Ashkenazi Jewish Genetic Diseases

Do you have Ashkenazi Jewish ancestry?

Yes

No

Why are you considering testing? Check all that apply.

I am pregnant or planning a pregnancy — or my partner is.

I have a family history of an Ashkenazi Jewish genetic disease (carrier or affected).

My partner has, or is a carrier of, an Ashkenazi Jewish genetic disease.

None of these

Family Planning: Medical guidelines say to offer carrier testing to couples who are pregnant or planning pregnancy when at least one member of the couple has Ashkenazi Jewish ancestors. Consider testing for at least cystic fibrosis, Canavan disease, familial dysautonomia, and Tay-Sachs disease. Experts agree that these conditions are serious and common enough to recommend testing. Carrier testing is also available for at least 12 other conditions that are unusually common in Ashkenazi Jews. Experts don't agree that everyone should be offered these tests because the diseases are either rare or less serious. You can read more about each of these diseases in the Ashkenazi Jewish Genetic Diseases section.

For practical reasons, the woman who is pregnant or planning a pregnancy is usually tested first if she is Ashkenazi Jewish. However, if only the man is Jewish, he should be tested first. Testing both of you at the same time is also reasonable, especially if you are already pregnant and worried about time.

  • When testing finds a gene mutation, the results are reliable that you are a carrier of that disease. Your partner should think about carrier testing for the same disease — if not already done. Most of the Jewish carrier tests aren't very effective for non-Jewish people. If your partner isn't Ashkenazi Jewish, you should talk to your doctor or genetic counselor about different carrier testing options.

    You are only at-risk to have a child with a Jewish genetic disease if you are both carriers of the same disease. Carrier testing before pregnancy gives you the most choices for planning your family if you are a carrier of one of these diseases. However, screening during pregnancy can still give you valuable information and reproductive options are available. See the Family Planning Options for Carriers section for more information.
  • When testing doesn't find a gene mutation, the results mean that you have a much lower chance of being a carrier for any of the diseases tested. You also have a much lower chance of having a child with those diseases. Because genetic testing cannot find all of the possible gene mutations that cause Jewish genetic diseases, normal test results don't completely rule out that you are a carrier. Testing for your partner isn't usually recommended.

Family History: Your chance of being a carrier of a Jewish genetic disease is higher because you have a family history of one of these diseases. See the Genetics of Ashkenazi Jewish Genetic Diseases section for information that can help you figure out your carrier risk if you don't already know. Your doctor or genetic counselor can also tell you this based on your family history.

If you decide to have carrier testing, try to find out the names of the mutations that run in your family. This will help the lab be sure they can find your family mutations with their test.

Carrier testing will find most of the mutations that cause these diseases in Ashkenazi Jewish people, but not all. If you can't find out your family's mutations, talk to your doctor or genetic counselor about the chance that regular carrier testing will miss a mutation. Other carrier testing options may be available.

Carrier Screening: When someone has or is a carrier of a Jewish genetic disease, the chance of having a child with the disease is higher. Because you are Ashkenazi Jewish, you have an increased chance of being a carrier of the same disease. The chance that you are a carrier depends on the disease and your family history. Your doctor or a genetic counselor can calculate your chance of having a child with the disease.

Carrier testing will find most of the mutations that cause these diseases in Jewish people, but not all. Talk to your doctor or genetic counselor about the chance that regular carrier testing will miss a mutation. If you are very concerned about the risk, other testing options may be available that can find more people who are carriers.

Family Planning: These carrier tests usually look for just the gene mutations that are more common in Ashkenazi Jews. Non-Jewish people can have these diseases, but different gene mutations usually cause them. So, this kind of genetic testing may not be useful for non-Jewish people. There are some exceptions. Some of these diseases are also more common in certain other people. For example, cystic fibrosis is common enough that carrier testing is offered to most women who are pregnant or planning pregnancy, no matter what their ancestry is. See Cystic Fibrosis Carrier Testing for information about this kind of testing.

Tay-Sachs is common in people who have French-Canadian or Cajun ancestry. Carrier testing for these reasons isn't covered here. If this is why you are thinking about testing, be sure to talk to your doctor or genetic counselor about getting the right test done — they don't all work the same.

If you were thinking about carrier testing because your partner is Jewish, your partner should have testing first. If your partner is a carrier, then you can proceed with testing, too.

Family History: A family history is a good reason to have carrier testing, but regular testing may not work well for you because you aren't Jewish. Because you have a family history of one of these diseases, you have a higher-than-average chance of being a carrier — no matter where your ancestors came from. See Genetics of Ashkenazi Jewish Genetic Diseases to figure out your carrier risk if you don't already know. Your doctor or genetic counselor can also tell you this based on your family history.

Regular carrier testing for the Jewish genetic diseases usually looks for just the gene mutations that are more common in Ashkenazi Jews. Non-Jewish people can be carriers of these diseases, but they may have different gene mutations.

If you decide to have carrier testing, try to find out the names of the mutations that run in your family. This will help your doctor order testing that is able to find your family's mutations. If you cannot find out the family mutations, you may need a different kind of genetic testing. Talk to your doctor or genetic counselor about the chance that regular carrier testing will miss a mutation and whether other carrier testing options may be better for you.

Carrier Screening: Because your partner has one or more mutations, you should consider some kind of carrier testing. However, regular testing may not work well for you because you aren't Jewish.

When someone has, or is a carrier of, a Jewish genetic disease, the chance of having a child with the disease is higher. But, their partner also have to be a carrier of the same disease to have a child with it. Your chance of being a carrier depends on the disease and your ethnic background. Your doctor or genetic counselor can calculate your chance to be a carrier and your chance of having a pregnancy with the condition.

Carrier testing for the Jewish genetic diseases usually looks for only the gene mutations that are more common in Ashkenazi Jews. Non-Jewish people can be carriers of these diseases, but they may have different gene mutations. You may need to consider different genetic testing options in some cases.

You didn't choose any of the most common reasons to have carrier testing for Ashkenazi Jewish genetic diseases. Carrier testing is usually done to find couples who have a higher chance of having a child with one of these diseases. Carrier testing can also be done to find a gene change, or mutation, in a family so that other family members can have reliable testing.

This tool only addresses carrier testing. Genetic testing may be used for other reasons that aren't included here. If you think genetic testing for these diseases would be useful to you, talk with your doctor or a genetic counselor.