PGx Testing Technology I Flashcards
FDA Approved PGx Drug Labels
can include:
- 1 gene, multiple drugs
- 1 drug, multiple genes
- one gene, multiple alleles
SPECIFIC FOR THE SPECIFIC ALLELE
- Ex) The LUMAKRAS KRAS G12C allele can only be applied to the G12C allele
Procedure for PGx Testing
- Sample Collection (saliva, blood)
- Laboratory
- Genetic Counselling
- Community Pharmacy
- Physician/Clinical Pharmacy Team
- Documentation
Who performs PGx Tests
- CLIA certified labs perform PGx testing
- can utilize FDA-approved platform/technology to perform PGx test
CLIA
Clinical Laboratory Improvement Amendments (CLIA) of 1988
- United States federal regulatory standards that apply to all clinical laboratory testing performed on humans in the U.S., except clinical trials and basic research
Where to find CLIA lab?
GTR: Genetic Testing Registry
Clinical Implication of PGx Test
Nature of PGx studies for discovering marker: how convincing
- sample size, design, replication
Evidence in applying the PGx in practice: how effective
- genotype patient first and test outcome
Overall impact of genotype on phenotype: how important
- 20 to 90% in all drugs
Genetic Testing Required
MUST DO IT
Genetic Testing Recommended
BETTER DO IT
Actionable PGx
DRUG LABEL MENTIONED –> your decision
Informative PGx
SUGGESTIVE
Limitations of PGx
- many genetic and non-genetic factors are involved
- do not rely on PGx alone especially when ADR is dangerous
- do not forget about non-genetic factors such as BMI, age, race, diet, gender, supplements
- not all FDA approved PGx testing is mandatory
- influence of PGx markers on inter-patient variability is variable
- cost may not bring enough benefit
Further Considerations of Technologies
a targeted test focusing on major alleles could be cheaper and quicker, but may miss other rare important alleles
Factors to be considered in PGx testing
Family History
Race/Ethnicity
Vulnerable Populations
Consent/Assent
Samples for PGx Testing
DNA is the target
- any nucleated cells/tissue contain germline DNA
Principles:
- easy to collect
- avoid contamination
- less invasive
- availability of standard procedure
Peripheral Blood
White Blood Cells (macrophages): DNA
- 2-6 mL is standard
- prefer EDTA anticoagulant tube (purple top)
- sterile technique to prevent contamination
- room temp same day/overnight delivery
Advantages:
- good and stable yield of DNA
- less contamination
- standard handling
- most common used medical sample
Limitations:
- invasive
- requires professional collection and handling
- special patients (chemo, radiotherapy have fewer cells and DNA sequence may be altered –> bone marrow transplant patients may have different DNA)
YOU CANNOT USE RBC’s
