1. GENETIC TESTING : EXAMPLES OF GENETIC TESTING: PRENATAL DIAGNOSIS HETEROZYGOTE CARRIER DETECTION PRESYMPTOMATIC DIAGNOSIS OF GENETIC DISEASE The analysis of chromosomes, DNA, RNA @ proteins To detect abnormalities that may cause a genetic disease

2. SCREENING TESTS Designed to detect treatable human diseases in their presymptomatic stage. Are not intended to provide definitive diagnoses. Aimed at identifying a subset of the population on whom further. DIAGNOSTIC TEST

3. EXAMPLES OF SCREENING TEST: • PAP TESTS - Recognition of cervical dysplasia. • POPULATION SCREENING -the presumptive identification of an unrecognized dz @ defect by the applction of test/examinations/othrprcedure -to sort out apparently well persons who probably hv a dzfrm those who prbbaly do not. -for hypercholesterolemia.

4. PRINCIPLES OF SCREENING

5. GENETIC SCREENING

6. What is genetic screening? • One of the fastest moving fields in medical science. • A technique to determine the genotype or phenotype of an organism. • It is often used to detect faulty or abnormal genes in an organism.

7. TYPES OF GENETIC SCREENING: • Newborn Screening -for inherited metabolic diseases 2. Heterozygote Screening -for Tay-Sachs disease

8. Newborn Screening • Newborns are tested for diseases and early diagnoses allows for immediate treatment (early detection &effective intervention). • A blood sample is tested for genetic disorders. • An effective public health strategy for treatable disorder such as PKU, galactosemia, hypothyroidism & sickle cell disease. • Some communities begun screening for Duschenne muscular dystrophy (by measuring creatinekinase levels in newborns)

9. Heterozygote Screening • To detect unaffected carriers of disease-causing mutations • Target population: group known to be at risk. • Usually genetic diseases involves in this heterozygote screening is “autosomal recessive disorder”- Tay-Sachs disease, -Thalassemia & Cystic fibrosis.

10. Presymptomatic Diagnosis • Indivisuals who are known to be at risk for a disorder can be tested (generally bcz of a (+)ve family history. • To determine whether they have inherited a disease-causing mutation before they develop clinical symptoms of the disorder. • Ex: Huntington Disease, adult polycystic kidney disease, hemochromatosis & autosomal dominant breast cancer.

11. Advantage of Presymptomatic Diagnosis • Can aid in making reproductive decisions. • Can provide reassurance to those who learn that they do @ do not carry a disease-causing mutation. • Early diagnosis may improve health supervision.