FAQs

Frequently asked questions

Find answers to common questions and concerns.

The HerediT® Cystic Fibrosis Carrier Screen tests your DNA for the mutations that cause cystic fibrosis. Your health care provider will take the sample (blood or cheek swab) in his or her office and send it to our laboratory. Test results are typically reported to your health care provider approximately 7 days after our laboratory receives your sample. Your result with either be positive (you are a carrier of the CF mutation) or negative (you are not a carrier of the CF mutation).

Cystic fibrosis is inherited in a recessive pattern. This means that in order to be affected a person must inherit two disease-causing mutations - one from each parent. Both parents must be carriers of one of the CF disease-causing mutations in order for them to be at risk of having an affected child. Carriers have only one mutation and usually have no symptoms of CF.

If both parents are carriers, there is a 1 in 4 (25%) chance with each pregnancy that a child will have CF. It is estimated that 1 in 25 Americans are carriers of CF1.

Cystic fibrosis is one of the most common genetic conditions in the United States. Changes in the CFTR gene cause the body to produce thick sticky mucus in the lungs, pancreas and other organs that can affect breathing and digestion. CF does not affect everyone the same way - some people may be more severely affected than others. Symptoms can range from moderate to severe and can even impact fertility. The average lifespan of someone with CF is 37 years2.

It is estimated that more than 10 million Americans are carriers of CF. While the risk of being a CF carrier is dependent upon one's ethnicity and family history, individuals of all racial and ethnic groups may be carriers.

For more information, please visit the Cystic Fibrosis Foundation website.

A negative or low-risk carrier screening test result significantly reduces your chances of carrying a mutation for a genetic disorder; however, it does not reduce your risk to zero. No carrier screening test can detect all mutations that may be present in carriers. Typically, with a negative result, the residual risks are significantly reduced such that you may feel significantly more comfortable without further testing. 

If you are identified to be a carrier of a genetic disorder, it does not mean that you have the condition or will become ill. It does mean that your reproductive partner should be offered testing for the same disorder. If both members of a couple are carriers for the same disorder, your doctor, genetic counselor or other health care provider will discuss reproductive and prenatal testing options with you. Genetic counseling can help you better understand these risks and the test results. Other family members may also be a carrier, so you may want to share your results with them so they can seek genetic counseling and testing if they are of reproductive age.  

Carrier screening can help you and your partner learn about the chance of having a child with a genetic disorder even before getting pregnant. Carrier screening for certain conditions is recommended for consideration by all pregnant couples. Screening might be helpful if you: 

  • Are considering having a child or are already pregnant
  • Have a family history of a genetic disorder
  • Are at increased risk for a specific condition based on ethnicity

A carrier of a genetic disorder has one of two copies of a gene that is not working properly. This is also known as a gene mutation. Anyone can be a carrier of a genetic disorder, even if no one in the family has been affected. The likelihood of being a carrier can be based on your ethnic background and family history. However, some disorders like cystic fibrosis (CF) or spinal muscular atrophy (SMA) are more common and carrier screening can be offered regardless of background.

Genetic disorders can be inherited in different ways. Some genetic conditions are the result of recessive inheritance. In this inheritance pattern, only a child with two gene mutations will be affected. If two people are carriers of the same genetic disorder, the risk of giving birth to a child with symptoms will be 25%.

In other conditions, a gene mutation is linked to the X chromosome, typically causing symptoms in males. In this inheritance pattern, women are more often unaware of their carrier status, and can have up to a 50% risk of passing the mutation to their sons.

Genetic carrier screening is one of the many tests that you or your physician can request before, or during a pregnancy to help predict your chances of having a child with a genetic disorder. Even if you are healthy, have no family history of a specific condition, or have previous healthy children, you may be a carrier of a genetic condition.

Wolf-Hirschhorn syndrome (4p minus) is caused by a missing piece of chromosome 4. This condition is characterized by distinctive facial features, growth delays, intellectual disability, hearing loss and seizures. This is a rare diagnosis, with approximately 1 diagnosis per 50,000 births.

Patient resources 

We encourage you to learn more about living with Wolf-Hirschhorn syndrome and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

Langer-Giedion syndrome (Tricho-rhino-phalangeal syndrome type II) is caused by a missing piece of chromosome 8. This condition is characterized by bone growths (exostoses), short stature, skeletal or bone findings, and distinctive facial features. Mild to moderate intellectual disability has been reported. This diagnosis is quite rare. Estimates of the frequency of this diagnosis are not well understood.

Patient resources

We encourage you to learn more about living with Langer-Giedion syndrome and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

Jacobsen syndrome is a rare condition caused by a missing piece of chromosome 11. Some features of Jacobsen syndrome include short stature, intellectual disability and distinctive facial features. Many can experience bleeding disorders and malformations of the heart as well. Jacobsen syndrome is not a frequent occurrence, with approximately 1 per 100,000 children diagnosed.

Patient resources

We encourage you to learn more about living with Jacobsen syndrome and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

A set of conditions is related to changes that take place on chromosome 15. Prader-Willi syndrome and Angelman syndrome are two conditions caused by a missing piece of chromosome 15. Most instances of Prader-Willi or Angelman syndrome are caused by a deletion of a part of chromosome 15. Depending on how the missing piece of chromosome 15 was inherited can determine what kind of traits a child will have.

Patient resources

We encourage you to learn more about living with Prader-Willi or Angelman syndromes and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

Missing a piece of chromosome 1 can cause a condition called 1p36. This chromosome change can result in poor muscle tone, difficulty with speech, characteristic facial appearances, and intellectual disability.

Patient resources

We encourage you to learn more about living with 1p36 syndrome and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

Cri-du-chat syndrome is a rare condition named for a unique, high-pitched cry in affected children. It is caused by a missing piece of chromosome 5. This is sometimes called 5p-, or 5p minus. Cri-du-chat is French for the term, “cry of the cat”, as these children have distinctive cries. Other symptoms, such as poor muscle tone, difficulty with speech, and intellectual disability can occur.

Patient resources

We encourage you to learn more about living with Cri-du-chat syndrome and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

22q11.2 deletion syndrome, or 22q for short, is a rare chromosome change with chromosome 22. A small piece of the chromosome is deleted, or missing. This piece of the chromosome contains many numbers of genes. Missing this piece of chromosome 22 causes health problems like heart defects, palate, or roof of the mouth defects, immune problems, learning delays, or other types of traits.

Patient resources

We encourage you to learn more about living with DiGeorge syndrome and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

Children with these conditions may be taller than average and usually have normal intelligence. A few may have learning or psychological issues. These conditions are not associated with birth defects and may go undiagnosed. People with these conditions may have normal fertility.

Patient resources

We encourage you to learn more about living with Triple X or XYY syndrome and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.


Boys with Klinefelter syndrome have two X chromosomes and one Y. These boys tend to be taller than average, may have delayed or absent puberty and are often infertile. Most have normal intelligence, but some may have learning or psychological difficulties.

Patient resources

We encourage you to learn more about living with Turner syndrome and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

Most girls with Turner syndrome have only one copy of the X chromosome. Many of these pregnancies are miscarried during pregnancy. Girls with Turner syndrome are usually shorter than average, have delayed or absent puberty and may be infertile. Most have normal intelligence, but some have learning difficulties. Children with Turner syndrome may also have heart or kidney defects. Identifying these abnormalities should prompt consideration of medical (endocrinologic) therapy in childhood. 

Patient resources

We encourage you to learn more about living with Turner syndrome and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

Trisomy 22 is a common cause of miscarriage. It is caused by an extra copy of chromosome 22. Many pregnancies with trisomy 22, unfortunately, do not continue to term. In rarer instances, babies with trisomy 22 can also have some cells with normal numbers of chromosomes. This is called a mosaic result. Mosaic trisomy 22 also has a significant risk for miscarriage.

Patient resources

We encourage you to learn more about living with trisomy 22 and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

Trisomy 16 is one of the most common causes of miscarriage. It is caused by an extra copy of chromosome 16. Many pregnancies with trisomy 16, unfortunately, do not continue to term. In rarer instances, babies with trisomy 16 can also have some cells with normal numbers of chromosomes. This is called a mosaic result. Trisomy 16 and mosaic trisomy 16 have a significant risk for miscarriage, pregnancy complications like growth delay, and other abnormal outcomes.

Patient resources

We encourage you to learn more about living with trisomy 16 and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

The sex chromosomes, X and Y, are associated with gender. Females typically have two X chromosomes and males have an X and a Y. Abnormalities in the number of sex chromosomes do not usually cause substantial developmental and intellectual impairment. Early diagnosis can help these children get services as needed in order to reach their full potential. Overall, about one in every 500 babies is born with a sex chromosomal abnormality3.

Patient resources

We encourage you to learn more about living with fetal sex chromosomal abnormalities and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

Patau syndrome is caused by an extra copy of chromosome 13. These babies have multiple birth defects and often don’t survive the first few months of life. Survivors are profoundly intellectually and developmentally impaired. This condition is less common than Down or Edwards syndrome and occurs in about 1 in 16,000 babies4.

Patient resources 

We encourage you to learn more about living with Patau syndrome and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

Edwards syndrome is caused by an extra copy of chromosome 18. Babies with trisomy 18 often have multiple birth defects, and many don’t survive the first few months of life. Survivors have serious health problems and typically do not walk or talk. About one in every 5,000 babies is born with trisomy 184.

Patient resources 

We encourage you to learn more about living with Edwards syndrome and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.


Down syndrome is a condition caused by an extra copy of chromosome 21. Children with Down syndrome have intellectual and developmental impairment. Babies with Down syndrome also have higher chances for certain health problems. Not everyone with Down syndrome is affected in the same way, and there is no way to determine before birth how a child may be affected5. Down syndrome affects about one in every 700 babies6, 7. The chance of having a child with Down syndrome increases with the woman’s age, but women of all ages and races may be at risk8.

Patient resources 

We encourage you to learn more about living with Down syndrome and other special needs, and have provided some helpful links below. While experiences can vary greatly, many families report happy and enriched lives as a result of thoughtful and informed preparation.

Anyone can have a pregnancy with a chromosomal abnormality – mothers of all ages, races and health conditions can be at risk. 

There is nothing a parent can do to cause a chromosomal abnormality, or prevent it. However, certain risk factors can increase the chance of having a pregnancy with chromosomal abnormalities. These include:

  • Advanced maternal age
  • Fetal ultrasound abnormality suggestive of aneuploidy
  • Personal or family history of chromosomal abnormalities
  • Positive serum screening test

The MaterniT® GENOME test test represents the latest scientific advancement in prenatal genetic testing. It analyzes the complete set of your baby’s chromosomes. Your health care provider may discuss the benefits and limitations of the MaterniT® GENOME test with you if:

  • There are concerns about chromosome abnormalities in your pregnancy
  • Ultrasound abnormalities have been identified and you are declining diagnostic testing as a first step
  • You have had earlier abnormal screening results for this pregnancy
  • You, your partner, or a prior pregnancy or child were identified with a chromosome abnormality
  • You have received inconclusive results from another fetal DNA screening test
  • You have asked to learn the most information you can about your baby’s chromosomes in the safest way possible

Inquire with our billing team or your insurance provider to see if the MaterniT® GENOME test is a covered benefit within your policy. Your financial obligation will be determined by the terms of your plan.

A Patient Assistance Program may also be available to you depending on your eligibility. Our goal is to make this important technology affordable for those who want it.

The MaterniT® GENOME test is unique in the level of information it provides. Currently, no other prenatal blood test can offer analysis of all chromosomes genome-wide.

As a pioneer and leader in fetal DNA testing, Sequenom Laboratories has significant experience in testing for fetal chromosome abnormalities from maternal blood. Should you wish to consider other options for fetal DNA testing, ask your health care provider about the MaterniT® 21 PLUS or VisibiliT™ noninvasive prenatal tests.

A positive result means that a chromosomal abnormality has been identified. Genetic counseling is recommended following any positive test result to discuss the findings and review options for further confirmatory testing. To assist in understanding an abnormal result, the MaterniT® GENOME test report also has an image of the chromosome change that illustrates what was discovered.

A negative result means that no chromosome changes were identified. Though highly reassuring, it is important to note that, like many tests during your pregnancy, a negative result does not mean your baby is unaffected, as the test cannot detect all possible abnormalities.

In some instances, one of the many chromosome targets analyzed may return an “uninformative” result. This does not necessarily indicate there is a problem with your pregnancy. Most commonly, it means that the amount of fetal DNA required for that particular result is insufficient, and re-testing or alternative testing may be considered.

The MaterniT® GENOME test analyzes all chromosomes in the genome. It reports fetal sex. In some pregnancies, chromosome abnormalities can be identified. Some of the abnormalities that can be identified include:

•  Any trisomy or monosomy

             •  Trisomy – extra copy of a chromosome is present (three instead of two)

             •  Monosomy – missing copy of a chromosome (one instead of two)

•  Select microdeletions – very small part of the chromosome is missing

•  Sex chromosome abnormalities – an extra or missing sex-determining X or Y chromosome

•  Many other chromosome changes throughout the genome. Sometimes, results may be indicative of chromosome changes from the placenta rather than the baby.

A health care provider specializing in high-risk pregnancies is accustomed to these types of results and can help provide you the context necessary to understand the results and plan for your pregnancy.

Small pieces of DNA from your developing baby can be found in your blood. By analyzing millions and millions of these pieces of DNA using precise methods, the MaterniT® GENOME test identifies chromosome abnormalities, ranging from very small to very large, in your pregnancy. Results are typically available five days after your sample has been received in the laboratory.

Chromosomal microarray, or “array”, is another technique to evaluate the genetic material in chromosomes. If a karyotype is a picture of chromosomes, then an array is that same picture using a zoom lens. Extra or missing pieces of chromosomes can be found with array that can’t be seen with a standard karyotype. Use of array in prenatal testing has increased over the last several years.

You can discuss more about the benefits and limitations of array and karyotype with your healthcare provider or genetic counselor.

Chromosomes are the structures inside our body’s cells that contain our genes. Genes determine how we grow and develop. All babies should have 46 chromosomes. A karyotype is a picture of these chromosomes. A karyotype can determine if a baby has extra, missing, or rearranged chromosomes. Having extra or missing genes chromosomes can cause birth defects. This method of genetic testing is a standard and has been used for several decades.

Amniocentesis involves taking a small sample of amniotic fluid. A thin needle is placed through the mother’s belly into the sac of fluid surrounding the baby. A few tablespoons of the amniotic fluid are taken out. The fluid has cells in it that have come from the developing baby. These cells can be tested for genetic conditions.

Amniocentesis is usually done after 15 weeks of pregnancy. Some women say that amniocentesis is not at all painful, while others may feel a pinch or sting, pressure, or cramping during the procedure. Most women have few or no problems after amniocentesis.

One of the most common methods of prenatal diagnostic testing is chorionic villus sampling (CVS). This procedure is performed by a doctor with special training and experience and is considered "invasive" because a sample of fetal cells is removed for examination. There is a small chance for miscarriage with this procedure. You should discuss the specific risks with your health care provider or genetic counselor.

CVS involves taking a small sample of tissue from the placenta. The placenta contains genetic material from the baby. This sample is tested to see if there are any genetic conditions.

CVS is done between 10 and 13 weeks of pregnancy. The location of the placenta determines how the procedure may be done. Sometimes, a thin needle is inserted through the mother’s abdomen. Other times, a thin tube is passed through her cervix (similar to a Pap smear). Some women say that the CVS is not at all painful, while others may feel pressure or cramping during the procedure. Most women have few or no problems after CVS.

There is a small chance that CVS test results will be inconclusive. This chance is about 1 in 100 (1%). If this happens, amniocentesis can be done to get more information.

RHD disease in an unborn baby can result in jaundice, anemia, brain damage, heart failure or even fetal death. Without treatment, severe cases may result in pregnancy loss or stillbirth.

Rhesus D (RHD) proteins are found on red blood cells. Many people know their blood type as a letter (A, B, AB, or O) and either “positive” or “negative.” If your blood type is positive, it means that you have RHD proteins on your red blood cells. If your blood type is negative, it means that you do not have RHD proteins on your blood cells. Your chance of being RHD positive varies by ethnicity. About 85% of Caucasians are RHD positive, while 92-98% of African Americans and Hispanics and 98-99% of Asians and Native Americans are RHD positive.

RHD incompatibility in pregnancy occurs when you are negative for the Rhesus D factor and your unborn baby is positive. There is a risk that during pregnancy your unborn baby’s blood cells might enter your bloodstream. This causes an immune response in you and your body starts to make antibodies. These antibodies can destroy your unborn baby’s red blood cells and cause anemia to develop in the baby.

Normally, this doesn’t happen in the first pregnancy. However, you can become sensitized during birth, and develop antibodies that could cause RhD incompatibility in your future pregnancies.

  1. Moskowitz SM, Chmiel JF, Sternen DL, Cheng E, Cutting GR. CFTR-related disorders. In: Pagon RA, Bird TC, Dolan CR, Stephens K, editors. GeneReviews. Seattle (WA): University of Washington; 2008. Available at http://www.ncbi.nlm.nih.gov/books/NBK1250. Retrieved December 15, 2010.
  2. Update on carrier screening for cystic fibrosis. ACOG Committee Opinion No. 486. American College of Obstetricians and Gynecologists. Obstet Gynecol. 2011;117(4):1028-1031.
  3.  Nielsen J, Wohlert M. Chromosome abnormalities found among 34,910 newborn children: results from a 13-year incidence study in Arhus, Denmark, Hum. Genet. 1991;87(1):81-83.
  4.  National Institutes of Health. 2009. Genetics Home Reference. Reviewed January 2009 from:http://ghr.nlm.nih.gov.
  5. Skotko BG, Kishnani PS, Capone GT for the Down Syndrome Diagnosis Study Group. Prenatal diagnosis of Down syndrome: How best to deliver the news. Am J Med Genet A. 2009;149A(11):2361 2367.
  6. American College of Obstetricians and Gynecologists (ACOG) Committee on Practice Bulletins. ACOG Practice Bulletin No. 77, January 2007. Screening for fetal chromosomal abnormalities. Obstet Gynecol. 109(1):217-228.
  7.  Parker SE, Mai CT, Canfield MA, Rickard R, et al. Updated national birth prevalence estimates for selected birth defects in the United States, 2004-2006. Birth Defects Res A. 2010; 88:1008-1016.
  8.  Sheets KB, Crissman BG, Feist CD, Sell SL, et al. Practice guidelines for communicating a prenatal or postnatal diagnosis of down syndrome: Recommendations of the National Society of Genetic Counselors. J Genet Couns. 2011;20(5):432-441.