Clinical Applications of Genetic Tests

1. Clinical Applications of Genetic Tests Mikenzie Lewis

2. Types of Genetic Tests • Diagnostic- establishes the basis of an existing disorder • Predictive- determines the presence of genetic condition when there are no obvious symptoms • Carrier- identifies heterozygotes • Prenatal- assesses a fetus for abnormalities

3. Diagnostic Testing • Based on physical signs and symptoms • Can be performed on any age • Not available for all genes or genetic conditions

4. Predictive Testing • Helpful to those who have family history of a disorder but show no features of the disorder at time of testing • Used often to detect cancers

5. Carrier Testing • Identifies heterozygotes for X-linked and autosomal recessive disorders that occur with high frequencies in certain populations • Knowledge of carrier status gives couples the opportunity to make reproductive choices

6. Prenatal Testing • Performed during pregnancy to determine whether there is a significant risk of having a child with a serious disorder • Counseling should precede a prenatal test

7. Detected by Prenatal Testing Accomplished with amniocentesis- an invasive procedure that involves taking amniotic from the mother and identifying fetal cells Can also be detected with ultrasound Down Syndrome

8. Test Results • Can be difficult to interpret and explain • Medical history, family history, and type of genetic test are important • Positive Result= change found in a particular gene, chromosome, or protein • Negative Result= no change found

9. References • http://www.dsamn.org/photogallery/photoAlbums/BuddyWalk2004/full/DSC03981.jpg • Pasternak, Jack J.An Introduction to Human Molecular Genetics, 2nd Edition. Hoboken, New Jersey: John Wiley & Sons, 2005, 526-528. • www.wikipedia.com