Depending on maternal age, miscarriages occur in 10% – 40% of human pregnancies. More than 50% of these losses are due to chromosome abnormalities, therefore analysis of the chromosomes from the products of conception (POC) is indicated. Until now, conventional karyotyping was used to analyze POC specimens, however, this method requires tissue culture and up to 25% of these cultures fail to grow. Chromosomally abnormal samples, such as monosomies and double aneuploidies habitually fail to grow. Tissue culture of POC specimens is also prone to maternal cell contamination which leads to over-reporting of 46,XX (normal female) karyotypes. Analysis of maternal and fetal DNA using quantitative fluorescent polymerase chain reaction (QF-PCR) technology allows detection of maternal cell contamination as well as some forms of polyploidy. Comparative Genomic Hybridization (CGH) and array CGH have overcome many limitations of conventional testing and are considered a significant advance in POC analysis. Reprogenetics is now offering POC analysis by aCGH with QF-PCR, utilizing our vast clinical experience with CGH, array CGH and molecular genetics.
Advantages of Molecular Karyotyping for POC specimens:
- Quick turn around time- Typically 24~72 hours after sample receipt
- No need for tissue culture- 25% more specimens with results compared to conventional testing
- More reliable results- Maternal cell contamination and poor growth not an issue for aCGH with QF-PCR
- Fewer false negative results-more than 60% of specimens definitively diagnosed compared to about 50% with conventional karyotyping
- Expected sex ratio of 50:50 confirmed (following elimination of maternal cell contamination)- this confirms that the test is operating as expected with very reliable results
- 6MB resolution allows detection of micro-deletions and duplications- Not detectable by karyotyping
- Well accepted by genetics experts as an alternative to karyotyping
- Formalin-preserved samples can be analyzed- In most cases if specimen was recently prepared
Reprogenetics will apply any out of pocket cost to the patient of POC testing to a future PGD cycle.