Editing Nucleic acid sequence (section)

=== Genetic testing ===
{{Main|Genetic testing}}

The DNA in an organism's [[genome]] can be analyzed to [[medical diagnosis|diagnose]] vulnerabilities to inherited [[disease]]s, and can also be used to determine a child's paternity (genetic father) or a person's [[ancestry]]. Normally, every person carries two variations of every [[gene]], one inherited from their mother, the other inherited from their father. The [[human genome]] is believed to contain around 20,000–25,000 genes. In addition to studying [[chromosome]]s to the level of individual genes, genetic testing in a broader sense includes [[biochemical]] tests for the possible presence of [[genetic disease]]s, or mutant forms of genes associated with increased risk of developing genetic disorders.

Genetic testing identifies changes in chromosomes, genes, or proteins.<ref>{{Cite web |date=16 March 2015 |title=What is genetic testing? |url=http://www.ghr.nlm.nih.gov/handbook/testing/genetictesting |url-status=dead |archive-url=https://web.archive.org/web/20060529002711/http://ghr.nlm.nih.gov/handbook/testing/genetictesting |archive-date=29 May 2006 |access-date=19 May 2010 |website=Genetics Home Reference}}</ref> Usually, testing is used to find changes that are associated with inherited disorders. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person's chance of developing or passing on a genetic disorder. Several hundred genetic tests are currently in use, and more are being developed.<ref>{{Cite web |title=Genetic Testing |url=https://www.nlm.nih.gov/medlineplus/genetictesting.html |website=nih.gov}}</ref><ref>{{Cite web |date=2008-09-11 |title=Definitions of Genetic Testing |url=http://www.eurogentest.org/patient/public_health/info/public/unit3/DefinitionsGeneticTesting-3rdDraf18Jan07.xhtml |url-status=dead |archive-url=https://web.archive.org/web/20090204181251/http://eurogentest.org/patient/public_health/info/public/unit3/DefinitionsGeneticTesting-3rdDraf18Jan07.xhtml |archive-date=February 4, 2009 |access-date=2008-08-10 |website=Definitions of Genetic Testing (Jorge Sequeiros and Bárbara Guimarães) |publisher=EuroGentest Network of Excellence Project}}</ref>