Download Genetic Diseases: diagnostic tools

GENETIC DISEASES
Define disease
• abnormal condition affecting the body of an
organism
– may be caused by external factors or it may be
caused by internal dysfunctions
– Ex. Limes disease
Ex. Celiacs Disease
Genetic disease
• Can a genetic disease be
inherited?
Think about it!
• Would you want to know if you had a genetic
disease? Why?
• Carrying the genetics for a disease does not mean
you will develop the disease. Would you still want
to know you carry the genes for the disease?
• If you had a life threatening disease and you have
had children, would you get them tested or leave
the choice up to them?
Diagnostic Tools
• Using diagnostic tools can be used to identify
various types of common genetic disorders:
– Ultrasound
– Chorionic Villus Sampling
– Amniocentesis
– Karyotype
– Human Genome Project
– Pedigree
Ultrasound
CVS: Chorionic Villus Sampling
Preformed earlier in
pregnancy
•10-12 weeks' gestation
Increases risk of miscarriage 0.5-1%
A catheter or needle is used to
biopsy placental cells
Amniocentesis
Preformed later in
pregnancy
•15-18 weeks' gestation
Increases rate of miscarriage: 0.25-0.5%
A needle is used to sample amniotic fluid
Why risk miscarriage?
•Women 35 years of age or older
are at increased risk for infants
with Down syndrome and certain
other types of aneuploidy
(abnormal # of chromosomes)
•Creating karyotype from CVS or
amniocentesis gives a definitive
answer about possible
aneuploidy.
Karyotype
(normal male; left, normal female, right)
Abnormal Karyotype
Human Genome Project (HGP)
The HGP was a 13-year project that was
completed in 2003
The 6 goals of the project:
•identify
•determine
•store
•improve
•transfer
•address issues that may arise from the project
Pedigree of genetic inheritance
Pedigrees can show how genetics are
inherited throughout a family.
They show whether a trait is dominant,
recessive or sex-linked.
Numbering individuals in pedigrees
Is shaded recessive or dominant?
Fill in the genotypes: complete
dominance example
Famous pedigree: hemophilia