Sequenom Prenatal Testing FAQs

FAQs

Frequently asked questions

Find answers to common questions and concerns.

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.


Health24-Langer-Giedion syndromeGenetics Home Reference–Langer-Giedion syndromeNational Society of Genetic Counselors

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.


11q Research & Resource GroupGenetics Home Reference–Jacobsen syndromeNational Society of Genetic Counselors


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.


Angelman Syndrome FoundationFoundation for Angelman Syndrome TherapeuticsNational Society of Genetic CounselorsNational Organization for Rare Disorders (NORD)


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.


1p36 Deletion Support & AwarenessGenetics Home Reference–1p36 deletion syndromeNational Society of Genetic Counselors

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.


5P Minus SocietyGenetics Home Reference–Cri-du-chat syndromeNational Society of Genetic Counselors

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.


22q FoundationGenetics Home Reference–22q11.2 deletion syndromeMayo Clinic–DiGeorge SyndromeNational Society of Genetic Counselors

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.


National Society of Genetic CounselorsNational Organization for Rare Disorders (NORD)




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.


Klinefelter Syndrome & Associated Disorders (U.S.)March of Dimes National Society of Genetic Counselors 


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.


March of DimesNational Society of Genetic CounselorsTurner Syndrome Society (U.S.)

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.


Chromosome 22 CentralGenetics Home Reference–Trisomy 22Miscarriage and Different Types of Trisomy 22National Society of Genetic Counselors

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.


Genetics Home Reference–Trisomy 16National Society of Genetic CounselorsNational Organization for Rare Disorders (NORD)Trisomy 16.org


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.


March of DimesNational Society of Genetic CounselorsNational Organization for Rare Disorders (NORD)

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.


Genetics Home Reference – Trisomy 13National Organization for Rare Disorders (NORD)National Society of Genetic CounselorsSOFT USA (Society for Trisomy 13, 18 and Related Disorders)

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.


Global Down Syndrome FoundationMarch of Dimes (U.S.)National Down Syndrome Congress (U.S.)National Down Syndrome Society (U.S.)National Society of Genetic Counselors (U.S.)SOFT USA (Society for Trisomy 13, 18 and Related Disorders)


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.

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.