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Which DNA Tests do I Need?
The human body is composed of trillions of cells, and each cell has a nucleus. Inside that nucleus are 23 pairs of chromosomes that contain genes. They are made up of DNA (deoxyribonucleic acid) that contains information on how to organize and maintain an organism. Each person has two copies of a given gene, one inherited from each parent. Variations of a given gene are called alleles. There are genes that govern eye color, for example – and different alleles or variations determine whether somebody has brown or blue eyes.
What are DNA tests used for?
The first DNA tests were developed in the 1980s, and they have a multitude of uses:
• Paternity testing, in which the geneticist looks for matches between a child and a possible father
• Ancestry testing is similar: Samples taken from two or more individuals are tested for similarities that could indicate relationship. It’s even possible to determine what ethnic group or groups someone belongs to.
• Genetic disorder testing, in which geneticists look for a mutation or change in a gene that can cause or increase the risk of a given condition. The geneticist can also identify family members who share or might develop the disorder
• Carrier testing is similar. It identifies people who have genes that can cause a disorder, but don’t have any symptoms themselves. Such people can pass the defective genes to their children, and if they marry somebody with the same defective genes, their children could have the full-blown disorder.
• A preimplantation DNA test or PGD is performed when a couple is undergoing in vitro fertilization (IVF). That’s the procedure done to make a “test tube baby,” and involves collecting eggs and sperm from the parents and combining them in a lab. A PGD is then done to determine if any of the embryos thus made have genetic disorders.
• DNA tests are also used for crime scene investigations. The police collect blood, saliva or hair samples, and geneticists can use the samples to try to identify a victim or suspect.
How is DNA testing done?
Regardless of the reason for getting a DNA test, the methods of performing one will depend on what the geneticist is looking for. The geneticist will always need a sample of the subject that contains their DNA. Samples usually come from the subject’s saliva, blood, skin or inside of their cheek.
After collecting the sample, the geneticist may choose from any of hundreds of genetic tests to use. The tests fall into several broad categories. In chromosomal tests, the geneticist studies whole chromosomes or long chains of DNA to seek major abnormalities like an extra chromosome. In molecular genetic tests, the geneticist studies single genes or short lengths of DNA. In a biochemical genetic test, the geneticist examines the proteins that make up a given gene.
Which DNA Tests Do I Need?
The answer to this is based on what you want the results for. Are you looking for health information, do you want to know the chances of getting breast cancer or other cancers? Are you looking for DNA based information about what vitamins to take or exercised to do? Then you want to check out the health DNA testing articles on this site. Are you looking for information about your ancestry and ethnicity? Do you have relatives with genetic diseases and want to know if you carry the same mutant genes? Then you are looking for carrier DNA tests. Are you adopted? Then look at our articles and reviews of testing sites for Adoption DNA. There are tests for twins to determine if they are identical, paternity testing, YDNA tests to compare males in your family ancestry or mtDNA tests to compare females in your family linage. There are tests to determine genetic compatibility of couples and even DNA personality tests. What do you want to know? Start with that question and go from there.
Ask yourself these questions and then go to the category pages that correspond to the type of test you are looking for. Then check out the reviews of the companies offering these tests. You can then compare the criteria of the different genetic testing companies.