Genotypic vs. phenotypic
May 22, 2004
Big question, but I was wondering your opinion. What are the advantages and disadvantages to phenotypic resistance testing and genotypic and what's a virtual phenotype? What do you use and why?
Response from Dr. Holodniy
These are difficult and complicated questions that are debated by many experts, and published studies are conflicting as to whether there is an advantage of one technology over another.
I have used all 3 technoliges in clinical practice. Genotyping is cheaper, faster, but not for the faint hearted, as it requires an understanding of the clinical significance of various mutations and their interactions.
Phenotyping is more expensive, takes longer, but provides relevant information as to how a particular patient's virus grows in the presence of each HIV drug.
A virutual phenotype is where a patients virus sequence is matched to a large database where many viruses have been sequenced and have had phenotypes performed. A probabilistic estimate of drug resistance or susceptibility is given based on the number of matches in the database. It is only slightly more expensive than genotyping, and appears equal to phenotyping in randomized trials, in terms of virologic outcome.
Get Email Notifications When This Forum Updates or Subscribe With RSS
This forum is designed for educational purposes only, and experts are not rendering medical, mental health, legal or other professional advice or services. If you have or suspect you may have a medical, mental health, legal or other problem that requires advice, consult your own caregiver, attorney or other qualified professional.
Experts appearing on this page are independent and are solely responsible for editing and fact-checking their material. Neither TheBody.com nor any advertiser is the publisher or speaker of posted visitors' questions or the experts' material.