noun. 1  Linguistics A predictable phonetic variant of a phoneme. 2  For example, the aspirated t of top, the unaspirated t of stop, and the tt (pronounced as a flap) of batter are allophones of the English phoneme &sol;t&sol;. 3  or Allophone Canadian A person whose native language is other than French or English.
What is genetic testing? Genetic testing is a type of medical test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a personâs chance of developing or passing on a genetic disorder. More than 1,000 genetic tests are currently in use, and more are being developed. Several methods can be used for genetic testing: Molecular genetic tests (or gene tests) study single genes or short lengths of DNA to identify variations or mutations that lead to a genetic disorder.
Once a person decides to proceed with genetic testing, a medical geneticist, primary care doctor, specialist, or nurse practitioner can order the test. Genetic testing is often done as part of a genetic consultation.Genetic tests are performed on a sample of blood, hair, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue.ewborn screening tests are done on a small blood sample, which is taken by pricking the babyâs heel. Unlike other types of genetic testing, a parent will usually only receive the result if it is positive. If the test result is positive, additional testing is needed to determine whether the baby has a genetic disorder.