Clinical Applications of Genetic TestsMikenzie Lewis

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

Diagnostic Testing

• Based on physical signs and symptoms

• Can be performed on any age

• Not available for all genes or genetic conditions

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

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

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

Down Syndrome

• 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

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

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