Prenatal cell-free DNA also known as cfDNA screening is a type of blood test that is done on a pregnant woman. The basic principle of this test is that some of the fetus’s DNA is present in the blood of the mother. In cfDNA screening this DNA is used to check for any kind of genetic disorder in the unborn baby.
The kind of disorder that can be identified by this test includes trisomy and Down syndrome.
Trisomy is a chromosomal disorder that occurs when the number of chromosomes changes. This change in the number of chromosomes occurs due to some factors like mutation, radiation, or any kind of defect that occurs during the formation of the genome.
These chromosomes carry your genes and these genes are passed down from you to your offspring. They carry all the necessary information that is required to determine the trait, gender, and basic structure of the unborn child.
Normally 23 pairs of chromosomes are present in each cell. And absence or presence of even one extrachromosomal pair causes a genetic disorder. One extra copy of these chromosomes causes trisomy and affects the development of the brain and body of the child.
One extra pair of 21st chromosomes in genetic material is found to be the cause of the genetic disorder known as Down syndrome. This disorder is very common.
One extra pair of 18th chromosomes causes Edwards syndrome.
One extra pair of 13th chromosomes causes Patau syndrome.
cfDNA screening has very little risk and although it’s safe it is not that precise in determining the genetic defects in the unborn child.