DNA (genetic) testing is a sophisticated method of defining an individual’s genes to determine paternity, establish the existence of genetic disorders and as a body identification tool for forensic specialists. Most DNA analyses are performed when the paternity of a child is questionable and child support is being sought by the mother and/or the courts.
What are Genes, Chromosomes and DNA?
As chemical subunits of deoxyribonucleic acid (DNA), genes represent a type of complex database that contains “instructions” necessary for the making each individual unique from any other person. All human cell nuclei in a single body contains DNA that is identical in chemical composition, except for fully grown red blood cells that possess no nuclei.
Genes are segments of the DNA double helix that encodes information for “creating” a specific person. The kind of information included in genetic material dictates traits such as hair color, eye color, skin color, feet size, etc.
Inside human cell nuclei are thready structures called chromosomes. Comprised of proteins and one DNA molecule, chromosomes are responsible for passing inherited traits from parent to offspring. DNA testing makes it possible to examine the two sets of chromosomes within a cell–one from the father and one from the mother–which can determine whether a child belongs to a certain set of parents.
How DNA Paternity Testing is Accomplished
By comparing DNA fragments taken from the child and the suspected father, geneticists can establish paternity with a 99 percent accuracy rate. Because a child receives half of his or her DNA from each parent, this means that 50 percent of the genes shared between a child and a parent are identical.
For example, if 10 different DNA fragments are compared (five from a child and five from the parent), then five of them should be identical to each other. If a professional DNA analysis reports this kind of result, there is a 99.99 percent probability that the child and parent are indeed biologically related.
Are All DNA Reports That Accurate?
Because extremely variable DNA fragments called “simple tandem repeats” are used for paternity testing as well as other identification purposes, testing an adequate number of these irregular genetic “loci” (definitive locations of DNA fragments on chromosomes), enhances the accuracy of a DNA test report.
People involved in a paternity (or maternity) test need to be aware that no test will be considered “100 percent” accurate because the slight possibility of an alleged parent’s DNA matching another child’s DNA by mere chance will always exist. Consequently, DNA reporting companies that examine 15 or more loci are preferable to those that check less than 15 loci.
DNA Testing for Diseases
These genetic tests are currently available for individuals wanting to know if a disease or disorder has been inherited:
*Inherited ovarian and breast cancer
*Fragile X Syndrome
*Sickle Cell Anemia
Testing for the presence of genetic disorders can help people with making practical decisions regarding the need for certain kinds of health care. In addition, receiving a negative DNA report can eliminate unnecessary worrying about what the future may hold in regards to the health of a newborn or older infant.
This post was written by an expert in the DNA field, Andrew Flanagan. He has reviewed the process for both legal and personal standpoints. When in Toronto, he visited the DNAForce laboratory which is equipped with the highest quality DNA testing equipment.