Frequently Asked Questions
Below you will find answers to some frequently asked questions from patients and providers. If you have any additional questions, please do not hesitate to contact us.

Carrier Screening

What is carrier screening?
Carrier screening is a simple saliva or blood test that determines whether either parent carries a genetic variant (or change) that could potentially cause an inherited disease in their children.
Why do I need carrier screening?
Carrier screening is designed to identify genetic changes in healthy people which can cause diseases when passed down to their children. Carrier screening is meant for people of reproductive age and is most efficiently done when both parents are screened at the same time. If you and your reproductive partner are identified as carriers of a variant in the same gene, and are at an increased risk for having an affected child, it is recommended that you meet with a genetic counselor to discuss all of the reproductive options available to you. This will help you make the best decisions for your growing family.
My partner and I both want to have a carrier screen. Do we need to be tested at the same time?

If you or your partner are currently pregnant, we recommend that both of you be tested at the same time. Most of the conditions included in our testing are autosomal recessive. This means that both the man and woman must be carriers for the same condition to have an increased risk of having an affected child. Completing testing at the same time will provide you with risk information in a time sensitive manner.

If you or your partner are not currently pregnant, we recommend that the woman completes carrier screening first. Our Expanded Carrier Screening includes 21 X-linked conditions. For these conditions, only the woman needs to be a carrier to have an increased risk of having an affected child. Depending on a woman’s results, her partner may not need to complete testing or will only need to complete testing for one or two conditions instead of the full panel.

If I am a carrier, what is the risk that my children will inherit the condition?
If both partners are identified as carriers of the same autosomal recessive condition, the couple has a 25% risk with each pregnancy to have a child affected with that disease. The couple also has a 50% chance with each pregnancy to have a child who is a carrier of the disease, and a 25% chance to have a child who does not inherit a variant from either parent and is not a carrier. If a woman is identified as a carrier of an X-linked condition, she has a 50% chance with each pregnancy to pass on the X chromosome with the variant and an increased risk to have an affected son or mildly affected daughter.
What are my reproductive options if I am a carrier?
When an at-risk couple is identified, our genetic counselors can provide information and support that can help you make important family planning decisions. Some of your reproductive options may include: chorionic villus sampling (CVS), amniocentesis, in vitro fertilization (IVF) with preimplantation genetic diagnosis (PGD), sperm or egg donation, or adoption. For most diseases, being identified as a carrier has no implications on one’s own health. However, for a small number of autosomal recessive conditions and X-linked conditions on this panel, a person identified as a carrier may manifest mild symptoms of the disease and/or manifest symptoms at a later stage in life than would be expected in a truly affected individual.
I was found to be a carrier for a certain condition. Does my partner only need to be tested for that one disease, or should they receive the full panel?
If a woman completed testing first and is found to be a carrier for a certain autosomal recessive condition, her partner only needs to be tested for that certain condition. If she is found to be a carrier for a X-linked condition, her partner does not need to be tested. If a man completes testing first and is found to be a carrier for a certain condition, it is recommended that his partner is tested for the same condition, as well as the X-linked conditions included on our panel. If you have questions about what testing your partner should complete, please contact us to receive additional guidance from one of our genetic counselors.

Genetic Conditions

What are genes and gene variants?
Genes are basic units of hereditary information that provide the instructions for all of the body’s traits and functions. You inherit approximately half of your genes from your mother, and half from your father. A change in a gene, also known as a variant, can cause that gene not to function properly. While most variants are harmless, some can result in medical conditions.
How are genetic disorders inherited?

There are multiple ways by which a genetic disease can be inherited. Autosomal recessive conditions, like cystic fibrosis, occur when variants are present in both the maternal and paternal copies of a gene. Each parent of an affected individual has one copy of a gene that works properly and one copy that does not. The parents are generally unaffected and are considered carriers of the disease. Their children may inherit two normal copies of the gene (unaffected), one normal copy and one variant copy (carriers), or two abnormal copies of the gene (affected with the genetic condition).

There are also genetic conditions, like fragile X syndrome, where the variant is linked to the X chromosome only. A chromosome is a structure that contains genes. Most people have 46 chromosomes, or 23 pairs. One chromosome in each pair is inherited from a person’s mother and one from the person’s father. The 23rd pair (called the sex chromosomes) determines whether a person is male or female. Typically, a male has one X and one Y chromosome, and a female has two X chromosomes. When a male child is conceived he receives the Y chromosome from his father and one of his mother’s X chromosomes (at random). When a female child is conceived, she receives the X chromosome from her father and one of her mother’s X chromosomes (at random).

If a woman is a carrier for an X-linked genetic condition, she will have a normal copy of a gene on one X chromosome and a copy with a variant on the other X chromosome. This means that her children may inherit the X chromosome with the variant. Male children who inherit an abnormal X chromosome are generally affected by the associated condition, whereas female children are normally unaffected carriers (carrier females may be affected, to a variable degree, based on disease or variant).

Sema4 Expanded Carrier Screen (ECS)

How is Sema4 ECS different than other genetic tests?
While some carrier screens only test for a few inherited conditions, Sema4 ECS is a comprehensive carrier screen. It screens for 281 genetic diseases, including hereditary conditions across many different ethnicities. Sema4 ECS also uses advanced genetic technologies for ~99% accuracy in results. If you are pregnant or planning for pregnancy, an expanded carrier screen such as this is strongly recommended to give you the best understanding possible of potential risks.
I think I may have had some genetic testing in the past. Do I need to have Sema4 ECS?
Sema4 ECS is a comprehensive and highly accurate carrier screen. It tests for 281 genetic diseases, with 99% accuracy. Due to this, genetic screening with Sema4 ECS can provide a greater depth of analysis than previous genetic testing you completed. It is therefore still beneficial to repeat testing through our laboratory. If you have additional questions or would like more guidance regarding this, please contact us to discuss your prior results with one of our genetic counselors.
How long does it take to receive the test results?
The turnaround time for the Expanded Carrier Screen is approximately 2 weeks.
How much blood do you need to do all of this testing?
Very little blood is needed to perform Sema4 ECS. Our largest panel of 281 diseases requires 3 tubes of blood (2 EDTA tubes [lavender top] and 1 ACD tube [yellow top]). Our smaller panels require even less blood.
I’m not comfortable getting my blood drawn. Do you accept any other specimen type for carrier screening?
Yes, we can also perform testing on a saliva specimen. Testing on saliva is just as accurate as blood for all disorders in question, except for Tay-Sachs disease. We are unable to perform Tay-Sachs biochemical analysis on saliva specimens. This decreases the accuracy of carrier screening slightly for this one disease.
You seem to be testing for a lot of diseases. What exactly is covered by Sema4 ECS?

While a comprehensive carrier screen is recommended if you are pregnant or planning for pregnancy, the Sema4 ECS panel can also be customized for your unique family planning needs. We have 4 test offerings:

  1. Standard Panel: The 4 diseases on this panel are recommended for persons of any ethnic background who want to be tested for only the standard diseases.
  2. High-Frequency Panel: These 10 diseases were found to occur at an increased frequency in all ethnic backgrounds.
  3. Comprehensive Jewish Carrier Screen: This panel of 96 disorders includes 48 diseases relevant to the Ashkenazim, 38 diseases relevant to the Sephardi and Mizrahi communities, and 10 diseases common to all people of Jewish descent.
  4. Expanded Carrier Screen: A comprehensive carrier screen, which tests for 281 disorders. This test is strongly recommended if you are pregnant or planning for pregnancy

For additional information or guidance on customizing your carrier screen, please contact us to speak with one of our genetic counselors.

I am 100% Ashkenazi Jewish. Do I need the full Comprehensive Jewish Carrier Screen for 96 disorders even if I don’t have any Sephardi or Mizrahi blood?
Even if you are of Ashkenazi descent, we recommend that you receive the Comprehensive Jewish Carrier Screen for 96 disorders. There are rare instances where self-reported Ashkenazi Jewish individuals tested positive for a mutation found primarily in the Sephardi or Mizrahi population. The same holds true for people of Sephardi or Mizrahi backgrounds who may be considering carrier screening.

Billing and Insurance

Do you take my insurance?
Most insurance providers cover Sema4 tests. To check on your specific insurance plan or to inquire about CPT codes, please call 212-241-8717 or contact us to speak with one of our billing specialists.
My insurance company is in-network with Sema4. What will be covered?

Copays, co-insurance, and deductibles vary by health plan and benefits design. To determine what your out-of-pocket expense may be, please contact your insurance provider via the number on the back of your insurance card or contact Sema4 by email at with the following information:

  1. Your name
  2. Your date of birth
  3. The name of your insurance company
  4. Your insurance ID number
  5. The genetic test(s) that your physician or genetic counselor have recommended for you
Is the amount on the Explanation of Benefits (EOB) that I received from my insurance company what I owe?
The EOB is an explanation of benefits and is not a bill. Please contact our billing specialists at 212-241-8717 to discuss any questions you may have about the EOB. Our billing specialists can also explain our payment options, including flexible payment plans and a program to help people who need financial assistance with their bills. Please note that certain exclusions may apply.
I have a Health Savings Account (HSA). What funds will be withdrawn?
If you have an HSA account, funds will be automatically withdrawn based on the EOB you receive from your insurance company. This will include unmet deductibles, co-insurances, co-pays, and denials. Please check your benefits prior to testing.
What if I don’t have insurance but still want to be tested?
If you don’t have insurance, we offer cash-discounted pricing. To learn more about your options, please contact us to speak with one of our billing specialists.
Can I pay for testing myself instead of having it billed through my insurance company?
Yes, in the case of cash payment, the cost of the genetic testing varies based upon the test ordered. Please contact our billing specialists at 212-241-8717 for further details.