Transcript GENETIC TESTING : •The analysis of chromosomes, DNA, RNA @ proteins •To detect abnormalities that may cause a genetic disease EXAMPLES OF GENETIC.

GENETIC TESTING :
•The analysis of chromosomes, DNA, RNA @ proteins
•To detect abnormalities that may cause a genetic disease
EXAMPLES OF GENETIC TESTING:
1.PRENATAL DIAGNOSIS
2.HETEROZYGOTE CARRIER DETECTION
3.PRESYMPTOMATIC DIAGNOSIS OF
GENETIC DISEASE
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
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/othr prcedure
-to sort out apparently well persons who probably
hv a dz frm those who prbbaly do not.
-for hypercholesterolemia.
PRINCIPLES OF SCREENING
DISEASE
CHARACTERISTICS
TEST
CHARACTERISTICS
• Serious &
relatively
common
• Natural history –
clearly
understood
• Acceptable &
effectve treatmt.
• Prenat diagnosis
shld availble.
• Acceptable to the
population
• Easy to perform
• Relatively
inexpensive
• Valid & reliable
SYSTEM
CHARACTERISTICS
• Resources fr
diagnosis &
treatmnt of
disorder must be
accessible.
GENETIC SCREENING
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.
TYPES OF GENETIC SCREENING:
1. Newborn Screening
-for inherited metabolic diseases
2. Heterozygote Screening
-for Tay-Sachs disease
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 creatine kinase
levels in newborns)
Heterozygote Screening
• To detect unaffected carriers of diseasecausing 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.
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.
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.