Genetics and Carrier Screening
All couples with ANY Jewish ancestry, including interfaith couples, should have pre-conception carrier screening for all Jewish genetic diseases.
If both parents are carriers of the same disease, there is a 1-in-4 chance, with each pregnancy, that their child will be born affected with that disease, a 2-in-4 chance that their child will be a carrier of that disease and a 1-in-4 chance that their child will be neither affected nor a carrier of that disease.
In an autosomal recessive condition (such as most Jewish genetic diseases), persons who inherit only one mutated gene show no signs of disease, but persons who inherit two mutated genes will be affected by the disease.
What it Means to be a Carrier
A carrier is an individual who does not develop the disease, but can pass on the gene with a mutation to his or her children.
In the case of the Jewish genetic diseases, which are termed “autosomal recessive,” one carrier parent can pass the carrier mutation, but both parents must be carriers of the same disease to have an affected child.
Some individuals may discover during the course of carrier screening that they are affected by one of the less severe or late-onset diseases.
How is Screening Done?
Carrier testing for all of the Jewish genetic diseases by DNA analysis can be done using blood or saliva. For Tay-Sachs disease screening, enzyme analysis using blood in addition to DNA analysis is required. For Alpha and Beta Thalassemia, a complete blood count (CBC) is done first.
The tests should be ordered and the results should be read by a knowledgeable doctor or genetic counselor trained to interpret genetic tests.
After several weeks a report is issued with results. It is important to note that all test results should be reported by a physician with experience in genetic screening or a genetic counselor.
Where can screening be done?
Currently there are several ways to obtain screening – your doctor’s office (usually an OB/GYN), Medical Genetics Program, or online genetics program that offers education, counseling and screening. For assistance in selecting a genetic counselor, visit nsgc.org.
Who Should be Screened? In a Couple, Who is Screened first?
If the woman is already pregnant, both partners must be screened simultaneously. If they are both carriers of the same disease, earlier fetal testing can be planned and there is more time for counseling and decision-making.
In a couple where both partners are Jewish, the usual practice is to screen the woman first, if she is not pregnant, generally at her OB/GYN’s office. If she is found to be a carrier of a specific disease(s), her partner must be screened for that disease(s) if they want to know if they are at risk for having a child with that disease(s).
If only one partner is of a Jewish background, that partner should be screened first. If he or she is found to be a carrier of a specific disease(s), the other partner must be screened for that disease(s), if they want to know their risk for having a child with that disease(s). Genetic Counseling is recommended.
When is the Best Time to be Screened?
Screening before pregnancy is optimal. This allows a carrier couple the greatest number of options. It is important to note that if the couple discovers their carrier status once they are already pregnant their only options, if the fetus is affected, are to continue or to terminate the pregnancy.
Is the Test Covered by Insurance?
Although every insurance plan is different, many cover testing for Jewish genetic diseases. Contact your insurance company for coverage information. A medical genetics program can be helpful in determining coverage. If screening is not covered, the JGDC may be able to provide referrals to low cost screening options or provide a letter of necessity for your insurance company.
In 2008 the Genetic Information Non-discrimination Act of 2008 (GINA) was signed into law. It’s a federal statute that protects American from being treated unfairly due to their genetic inheritance.
As of May 2009, health insurers may not deny or limit coverage or charge higher premiums based on a person’s genetic information. As of November 2009, employers may not use genetic information to make decisions about hiring, firing, promotion or job placement.
There are multiple options which enable carrier couples to build a healthy family. Each couple needs to make their own informed decision, based on the disease or diseases for which they are carriers and other personal considerations. Genetic counseling can explain options in depth.
A carrier couple may choose to become pregnant and test the fetus early in the pregnancy. In the case of an affected fetus (a 1-in-4 chance for each pregnancy), the couple can decide whether to continue or terminate the pregnancy. In order to test the fetus, the parents’ carrier status must be known.
A carrier couple may choose in-vitro fertilization (IVF) with pre-implantation genetic diagnosis (PGD). The egg is fertilized outside the body and embryos are tested at a very early stage for the disease(s) carried by the parents. Only unaffected embryos are implanted in the womb.
A carrier couple may choose to use egg or sperm from a screened non-carrier donor.
A carrier couple may choose to adopt.
A carrier couple may choose not to have children.
A carrier couple may choose not to marry. In this case the couple needs to be screened before engagement or marriage.
If you or your partner have any Jewish ancestry, or are an interfaith couple, it is important that you ask to have pre-conception carrier screening for the Jewish genetic diseases.
If you are already pregnant, it is important to discuss screening with your doctor as soon as possible.
Tell you doctor about:
Your plans to become pregnant
All family heritage, whether Ashkenazi (German, French or Eastern European), Sephardic (Mediterranean) or Mizrahi (Persian/Iranian or Middle Eastern).
Any family history of genetic diseases.
If you have been screened before, and your test results are available, bring them to your appointment.
If you do not have a doctor, or if your doctor does not offer genetic screening and counseling, you can contact a hospital based medical genetics program or an online genetics program that offers education, counseling and screening. Screening resources are listed at JewishGeneticDiseases.org. You can also search for a genetic counselor in your area at nsgc.org.
Whether you are currently single, dating, engaged or married, you may be thinking about having children or adding to your family.
If you or your partner have any Jewish heritage, you need to consider genetic screening.
If both of you are carriers of the same disease, it is best to have this information before pregnancy. A genetic counselor can discuss your options for building a healthy family.