EXAM SCRIPT VERIFIED QUESTIONS AND
SOLUTIONS GRADED APLUS
●● What sample is needed for genetic testing? Where can these samples
come from?
Answer: We can extract nuclear DNA from any cell with a true nucleus
- Blood
- Cheek (buccal) swabs - Saliva
- Skin cells
- Hair follicles
- Tissue blocks obtained in
surgery
- Biopsy from living or
deceased persons
●● What is Cell-free DNA? Where does it originate?
Answer: • Collected from plasma or urine
• Small pieces of circulating cf DNA
• Originating from the placenta in pregnant women.
• Originating from the tumor in cancer patients.
,●● What are the types of genetic testing?
Answer: - Diagnostic testing
- Carrier testing
- Predictive testing
• Presymptomatic
• Predispositional
- Prenatal testing
●● What is diagnostic testing?
Answer: ❖ Done to confirm or rule out a particular diagnosis in a
symptomatic person
❖ Can clarify a diagnosis
❖ Clinical or biochemical tests may be a better choice for some
disorders
❖ Provides information about other family members
Example: Testing for Fragile-X in a boy with mental retardation is an
example of
diagnostic genetic testing.
●● What are the two types of predictive genetic testing?
, Answer: - Presymptomatic
- Predispositional
●● What is Presymptomatic Predictive Genetic testing?
Answer: ❖ Positive result means the person will get the disease
❖ Example: Huntington disease
●● What is Predispositional Predictive Genetic Testing?
Answer: ❖ Having a gene variant increases the likelihood that a person
will get a genetic disease
❖ Example: testing for BRCA1/2 alleles
❖ Providers must interpret the test results based on the personal and
family history of the
patient. Negative results on BRCA genetic tests provide only limited
reassurance unless
there is a family member with a known mutation, and even then, it is
important to recall
that >90% of breast cancer cases are not due to BRCA mutations.
●● What is Huntington's disease?