NIFTY – Fetal DNA testing

FAQ

• What is NIPT or what is fetal DNA?

  Flowing through the mother's blood there is also some free DNA, some 10% of which originates from the fetus. This is fetal DNA. Using sophisticated technologies, this DNA can be analyzed for the purpose of identifying fetal abnormalities.
  The NIPT analyzes the fetal DNA.

• What is trisomy?

  Every cell in our bodies contains 23 pairs of chromosomes - pairs 1 to 22, plus a pair of gender chromosomes (in females - two X chromosomes; in males - one X chromosome and one Y). Each pair is made up of one chromosome from the father and one chromosome from the mother. In rare instances, one of the parents passes on to the fetus two chromosomes instead of one such that the fetus ends up with three chromosomes of a particular type rather than the normal pair. This is known as trisomy. It occurs only at conception and thus there are no genetic tests that could foresee such a condition prior to the pregnancy. The most common trisomy occurs with chromosome 21 and causes Down syndrome.

• What are the major advantages of NIFTY fetal DNA testing?

  
  

  • Based on clinical trials, NIFTY is the most accurate test of its kind.
  • NIFTY-Extended is the most comprehensive test of its kind and the only test that examines all 23 pairs of the fetal chromosomes. Thus far, the test has identified more than 90 syndromes.
  • NIFTY is a noninvasive test that poses no risk to the mother or the fetus and can be done as early as the 10th week of the pregnancy.
  • The NIFTY test is conducted at BGI laboratories, the most sophisticated and experienced laboratories of theis kind in the world.

• For which syndromes does NIFTY test?

  NIFTY-Extended is the most comprehensive test of its kind and the only test that examines all 23 pairs of the fetal chromosomes. The test can identify syndromes caused by an irregular number of chromosomes or by chromosomal deletions or duplications (more than 40 syndromes have been identified thus far). NIFTY-Basic tests for the most common trisomies (Down syndrome, Edwards syndrome and Patau syndrome) and the sex chromosomes.

• Does a NIFTY test replace an amniocentesis?

  An amniocentesis is carried out between week 16 and week 20 of the pregnancy. In addition, an amniocentesis is an invasive test involving a certain degree of risk for both the mother and the fetus. In Israel, every woman who undergoes an amniocentesis is required to sign a consent form that states that 0.5% of such tests result in miscarriages (studies show varying rates for this estimate). An amniocentesis can test for a large number of defects stemming primarily from an irregular number of chromosomes (with Down syndrome the most common), as well as other changes in the chromosomal makeup. Furthermore, an amniocentesis allows for identifying tiny changes in chromosomes by means of "genetic chip" analysis.

  Conducted from the 10th week of pregnancy and onwards, the NIFTY test is noninvasive and poses no risk to the mother or the fetus. Nevertheless, the NIFTY test does not check for all the rare genetic defects that are tested for in an amniocentesis. Thus, the NIFTY does not come to replace an amniocentesis, but instead allows women, particularly those who do not want to undergo an amniocentesis, to perform a simple blood test to identify, with a very high degree of accuracy, Down syndrome, Edwards syndrome, Patau syndrome and more.

• Does a NIFTY test replace an AFP test?

  The NIFTY test is significantly more accurate than an Alpha Fetoprotein test when it comes to identifying Down syndrome (Edwards syndrome and Patau syndrome, too). Thus, with regard to such conditions, the NIFTY test certainly can replace an AFP test. However, an AFP test can indicate risks associated with defects for which the NIFTY does not test, such as spina bifida. Therefore, it is advisable to carry out an AFP test even if one decides to undergo the NIFTY test.

• Are there instances in which the NIFTY test is not advisable?

  In all instances, it is advisable to consult with your physician to determine which tests would be most appropriate for you.  The test is inadvisable in the event that one of the parents is known to suffer from chromosomal translocations or any other chromosomal structural disorder. A recent blood-transfusion should be stated when scheduling an appointment.

• Do the HMOs (Maccabi, Meuhedet and Clalit) and private insurance companies cover some of the cost?

  Currently, some HMOs and private insurers partially cover the costs of the NIFTY test. We advise all women to consult on the matter with their insurers.

• Why is the blood sample drawn on a specific day and at a specific time?

  As aforesaid, the blood samples are sent for analysis abroad; the testing times are therefore coordinated with the dispatch times.

• What is the difference between NIFTY-Basic and NIFTY-Extended?

  NIFTY-Basic tests for the most common trisomies (Down syndrome, Edwards syndrome and Patau syndrome) and the sex chromosomes. NIFTY-Extended in addition tests all 23 pairs of the fetal chromosomes and can also identify duplications or deletions (NIFTY-Extended has successfully identified more than 90 syndromes thus far).