Mitochondrial DNA together with the assessment of their pathogenicity. Mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. In humans, the 16,569 base pairs of mitochondrial DNA encode for only 37 genes. Human mitochondrial DNA was the first significant part of
Cell-free fetal DNA from maternal DNA fragments. Approximately 11 to 13.4 percent of the cell-free DNA in maternal blood is of fetal origin. The amount varies widely from one pregnant woman to another. cffDNA is present after five to seven weeks gestation. The amount of cffDNA increases as the pregnancy progresses. The quantity of cffDNA in maternal blood diminishes rapidly after childbirth. Two hours after delivery, cffDNA is no longer detectable in maternal blood. Analysis of cffDNA may provide earlier diagnosis of fetal conditions than current techniques. As cffDNA is found in maternal blood, sampling carries no associated risk of spontaneous abortion. cffDNA