Clinical Applications of Genetic Tests Mikenzie 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 hotoAlbums/BuddyWalk2004/full/DS C03981.jpghttp:// hotoAlbums/BuddyWalk2004/full/DS C03981.jpg Pasternak, Jack J.An Introduction to Human Molecular Genetics, 2 nd Edition. Hoboken, New Jersey: John Wiley & Sons, 2005,