The Harmony® Test assesses the risk of trisomies 21, 18 and 13 and, upon request, the risk of numerical changes to the sex chromosomes X and Y or the risk of DiGeorge syndrome. In the event of a negative test result with no pathological ultrasound findings, you can rule out the tested disorders in your unborn child with a high degree of probability.
The exception is trisomy 13, for which latest figures show a detection rate of 85 – 90% of cases by non-invasive tests of maternal blood (NIPT). This chromosomal disorder, however, is very rare, with a frequency of 1:10000 (depending on the mother’s age)1 and can be easily detected by an ultrasound scan, e.g. during first trimester screening.
The Harmony® Test is able to detect 75% of all 22q11.2 microdeletions, including those smaller than 3 Mb at a false-positive rate of 0.5% 2. The screening for DiGeorge syndrome by the Harmony® Test determines the probability for the presence of the genetic disorder, however, it is not able to ascertain the clinical severity of the microdeletion.
All NIPT methods have limits when it comes to the detection of mosaics or structural chromosomal changes. The Harmony® Test only investigates the most common chromosomal disorders, so it cannot identify any physical disorders in the child; therefore a negative (normal) test result does not rule out the possibility of other disorders in your unborn child. A number of these disorders can be detected with an accurate ultrasound scan, often from the 12th week of pregnancy. A genetic test such as the Harmony® Test can never replace a thorough ultrasound scan.
If you have any further questions your physician will be pleased to help during your entire pregnancy. You can also contact our team of physicians at any time should you have any questions.
Positive (abnormal) test result
If the Harmony® Test returns a positive (abnormal) result, there is a relatively high probability that your child has one of the tested chromosomal disorders. However, since the test can also produce a false-positive result, a positive (abnormal) finding must always be confirmed by a second diagnostic, invasive method (chorionic villus sampling or amniocentesis). Subsequent chromosome analysis of those samples can then provide definitive diagnostic results. Within the scope of genetic counseling, your physician will explain in detail the possible effects of the probable chromosomal disorder for your unborn child and provide you with information about further counseling options.