More than 60% of miscarriages are caused by chromosomal defects of the embryo or fetus. Sensitive diagnostic tools are needed to provide accurate diagnosis of the problem to minimize the risk of pregnancy loss. The methods used so far to analyze miscarriage material had many limitations. Experts say that the use of innovative technology, such as next generation DNA sequencing, allows them to get a lot of valuable information from difficult to study tissues.
Miscarriage, pregnancy loss or premature birth often occur as a consequence of the presence of genetic errors in a developing child. In most cases these are chromosomal copy number errors i.e., aneuploidy. These errors cause the occurrence of Down, Turner, Klinefelter, Patau or other often fatal, syndromes. Appropriate diagnostics and determination of the cause of miscarriage can help to plan a course of treatment that would allow a couple to have healthy off spring.
Unfortunately, in many cases, women are not offered the choice to perform the analysis of material from the miscarriage, even though it can provide crucial data for further treatment – says Dr. Sebastian Pukszta of the INVICTA Genetic Laboratory. Additionally it often turns out that the samples are contaminated with the woman’s genetic material. The older methods fail in such situations, whereas new solutions can provide much greater opportunities.
INVICTA Genetic Laboratory has been the first in the world to introduce the genetic diagnosis of the causes of miscarriage using the NGS method (Next Generation Sequencing). The iMGE Test™(INVICTA Miscarriage Genetic Evaluation) can detect all possible chromosomal aberrations and enables accurate analysis of the test material. Accurate and reliable results can be obtained. Testing of the miscarriage material has been so far mainly performed using the classic karyotyping method.
Before the DNA could be tested the live cells from the sample had to be cultured. Time and conditions of obtaining the sample, as well as transport problems were lowering the chances of getting a high quality material. It was often impossible to obtain a clear result. Next Generation Sequencing (NGS) uses semiconductor chips to direct translate chemically encoded genetic information into digital information. It is a very accurate tool that allows identification of any genetic variability.
What is the test ?
The first step is to obtain the material in a hospital. The doctor should prepare a sample (tissue sample in saline or paraffin block) and send it to the lab. The iMGE Test™is provided as a mail order kit to facilitate this process. When the sample reaches the laboratory it is first pre-evaluated (macroscopically and microscopically) by a pathologist. A specialist isolates the most valuable fragments and forwards them for further analysis to the molecular biology laboratory. That’s where the DNA sequencing is performed with the use of NGS. The degree of potential contamination of the sample material with maternal DNA, the so-called testing for MCC (Maternal Cell Contamination) is performed. In most cases, if the supplied material has been obtained correctly, despite the presence of a some maternal genetic material we can accurately judge whether miscarriage was caused by genetic factors. Sometimes it maybe necessary to obtain a DNA sample from the mother.
When to perform the test and what can the results tell us ?
The optimal solution would be to provide specialized diagnostics for every single miscarriage. This would allow the exclusion of the genetic factors and help plan further treatment. Such tests should be recommended patients experiencing recurrent miscarriages, women who have experienced difficulties in conceiving and women aged over 35 who miscarried – said prof. Krzysztof Łukaszuk, Medical Director of INVICTA Fertility Clinics.
A result confirming presence of genetic abnormalities in the miscarriage material is one of the indications for further diagnosis of expectant parents, as well as consideration of preimplantation genetic testing. Preimplantation genetic diagnosis performed in the course of the IVF treatment is the option to analyze the genetic material from the embryo before the transfer to the woman’s uterus. For many couples this is the only chance for healthy offspring.