UNITY Screen™ NIPT for Patau Syndrome (Trisomy 13)
UNITY Screen™ is a blood test that many expectant parents use to help understand if their baby may be at high-risk for Patau syndrome (trisomy 13) or other genetic conditions. Patau syndrome is not passed down in families, so this non-invasive prenatal test (NIPT) can be offered to all pregnant patients.
Incidence at Birth
Patau syndrome occurs in 1 in 16,000 pregnancies.
Common Names
Trisomy 13 is another name for Patau syndrome.
Causes
This condition is caused by a person having an extra copy of chromosome 13.
What Is UNITY Screen™ for Patau Syndrome?
UNITY Screen™ non-invasive prenatal testing, or NIPT, is a type of test that healthcare providers may order to find out if an unborn baby has a higher or lower risk for a genetic condition called Patau syndrome or trisomy 13. It works by analyzing the baby's DNA from the placenta, which is found in the mother's blood. This test is different from other prenatal tests because it's non-invasive, which means it only requires a blood sample from the pregnant patient.
How UNITY for Patau Syndrome Works?
What Is Patau Syndrome?
Children with Patau syndrome have three copies of chromosome 13. This extra genetic material typically causes birth defects across multiple areas of the body including the brain, heart, kidneys, hands, and feet. Children with trisomy 13 have severe intellectual disability. They commonly experience feeding and breathing difficulties. Medical interventions or surgeries may prolong life.
What Causes Patau Syndrome?
Trisomy 13 or Patau syndrome is caused by inheriting an entire extra chromosome 13 in all the cells, or building blocks, of a person’s body. This extra genetic material leads to differences in the development and growth of a pregnancy. More rarely, some individuals may only inherit part of an extra chromosome 13, called partial trisomy 13 syndrome, or some may have an extra chromosome 13 in only some of the cells of their body, called mosaic trisomy 13 syndrome. Inheriting all or a portion of an extra chromosome is random, however the chance of having a baby with Patau syndrome increases as the mother's age increases.
Signs and Symptoms of Patau Syndrome
There are certain signs of trisomy 13 your provider may look for during a second and third trimester ultrasound. Since trisomy 13 can cause a wide range of medical and developmental concerns, every pregnancy can look different. Some common ultrasound features include:
- Brain abnormalities
- Heart defects
- Kidney abnormalities
- Extra fingers or toes (polydactyl)
- Cleft lip and/or palate
- Characteristic facial features
Babies born with Patau syndrome may have additional birth defects that were not detected on ultrasound and can experience respiratory and feeding difficulties and seizures after birth.
Who Should Get Prenatal Screening for Patau Syndrome?
The American College of Obstetricians and Gynecologists (ACOG) recommends that all pregnant people be offered screening for chromosomal abnormalities, including Patau syndrome. It's especially important for women who are older, have had a previous pregnancy with trisomy 13, or have a family history of the condition. You can discuss all your genetic screening options in pregnancy with your healthcare provider.
UNITY Screen™ Prenatal Screening for Patau Syndrome Workflow
Consult
The UNITY Screen™ NIPT is ordered through your healthcare provider. You can schedule a complimentary genetic counseling session to answer any questions about the test before or after your blood is drawn.
Test: As early as week 9
Your blood sample can be collected in the doctor’s office, at a local lab, or through our mobile services. Your blood sample is shipped to our CAP/CLIA certified laboratory in northern California.
aneuploidy NIPT + fetal antigen results: As early as week 10
Within about one week from lab receipt, your doctor will receive the baby’s risk score for aneuploidies (chromosome conditions) and fetal antigens (if added). You will receive a text or email indicating your results are available on our portal, or your healthcare provider may call you with the results.
carrier status + single-gene NIPT results: As early as week 11
Within about two weeks from lab receipt, your doctor will receive the results of your maternal carrier status testing and single-gene NIPT. If you were found to be a carrier for any of the recessive conditions, single-gene NIPT is automatically run to determine your baby’s risk of being affected. You will receive a text or email indicating your results are available on our portal, or your healthcare provider may call you with the results.
How Accurate Is NIPT for Trisomy 13?
UNITY Screen™ results can tell you if there is a higher or lower chance that your baby might have Trisomy 13. This is a screening test and not a diagnostic test. If you receive a high-risk result, it does not mean that the baby has Patau Syndrome.
However, it may indicate a need for diagnostic testing for trisomy 13 in pregnancy or after birth. It's important to discuss the test results with a healthcare provider to understand what they mean and decide how you would like to move forward with possible next steps.
- Before Birth
Testing during pregnancy can be performed by obtaining a sample of placenta (chorionic villus sampling or CVS) or fluid around your baby (amniocentesis) which both contain DNA that is representative of your baby. A CVS is ideally performed between 10 to 13 weeks pregnancy while an amniocentesis is typically performed between 15 to 24 weeks pregnancy. Both procedures are generally safe, but have a small risk for pregnancy complications, including miscarriage. - After Birth
Infants with Patau syndrome typically have physical features of the condition. However, if confirmatory testing during pregnancy is not done, the baby’s pediatrician should be informed of this result. The baby can have chromosome analysis performed after birth. Physical exam by a medical geneticist can also be considered.
Resources
Frequently Asked Questions
Explore our additional resources and find answers to common questions.
How can I reduce my risk of having a child with Patau syndrome?
Because trisomy 13 is usually a random chromosome change that happens at the time of conception, there is nothing you can do to prevent a pregnancy from having trisomy 13. These types of chromosome changes are not usually inherited, but if you are over the age of 35 or have certain medical history, you may have a higher chance to have a pregnancy with these types of conditions.
What is the difference between trisomy 13 and trisomy 18?
Trisomy 13 and trisomy 18 are both rare chromosome conditions that can cause significant physical and developmental difficulties. However, there are some differences between the two conditions based on the extra genetic material a pregnancy has. Trisomy 13 is caused by an extra copy of chromosome 13 and is associated with birth defects like cleft palate, heart defects, and brain malformations. While trisomy 18, or Edwards syndrome, is caused by an extra copy of chromosome 18 and can cause abnormalities such as a small head, heart defects, and kidney abnormalities.
How does trisomy 13 affect delivery?
Trisomy 13 can cause a range of physical and other developmental delays and abnormalities that can impact delivery, which may require special delivery considerations or interventions. In some cases, a healthcare provider may recommend inducing labor early to reduce the risk of complications. It is important for expectant parents to work closely with their healthcare provider to develop a delivery plan that takes into account the individual needs of the patient and the potentially higher risks associated with the condition of the unborn baby.
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