The scope of prenatal diagnosis for women at increased risk for aneuploidies
: views and preferences of professionals and potential users.
Routine first trimester screening strategy has the potential to detect a much broader range of chromosomal aberrations, including triploidy, small supernumerary marker chromosomes and rare numerical and/or structural chromosomal abnormalities in addition to common aneuploidies
Detection of trisomy 21 and other aneuploidies
by paralogous gene quantification.
Clinical laboratories use different techniques to perform cfDNA analysis for fetal aneuploidies
(3), including comparing single-nucleotide polymorphisms in the cfDNA to reference (usually maternal leukocyte) DNA, using oligonucleotide arrays with expanded coverage of the chromosomes of clinical interest, and whole genome sequencing, in which the sample's cfDNA is compared to a euploid reference genome.
The most common aneuploidies
in the human population are trisomy 16, 21, 22 and X chromosome monosomy.
(c) Correlation between OSI and the number of euploid embryos and the aneuploidies
There were no reported aneuploidies
among the cases with known birth outcomes (90.2%) at the end of the study.
The risk for aneuploidies
increases with maternal age.
(15) In prenatal series, trisomies 13, 18, and 21 make up approximately two-thirds of all clinically significant aneuploidies
. (16,17) Given that cfDNA detects only these aneuploidies
, the other third will not be identified prenatally in patients who choose cfDNA.
Fetal chromosomal abnormalities are the primary etiology of SM, especially aneuploidies
. [sup], Chromosome aneuploidy and polyploidy consist of more than 96% of chromosomal abnormalities in spontaneous abortion and X, Y, 13, 16, 18, 21, and 22 are frequently involved.
The follow-up of these patients was not complete, but the authors estimate that in 20%-44% of cases where multiple aneuploidies
are detected and the results are discordant, an occult maternal cancer is the explanation.
Application of the short tandem repeat loci in prenatal diagnostics of the most common aneuploidies