Thursday, December 15, 2022

PharmGKB selected in the first list of Global Core Biodata Resources

We are pleased to announce that PharmGKB is included in the first list of Global Core Biodata Resources (GCBRs), a collection of resources whose long term funding and sustainability is critical to life science and biomedical research worldwide.

The Global Biodata Coalition (GBC) brings together major public and charitable funders, with the aim to “stabilize sustainable financial support for the global biodata infrastructure and in particular to identify for prioritized long-term support a set of Global Core Biodata Resources that are crucial for sustaining the broader biodata infrastructure.” After a rigorous two-stage process evaluating scientific quality and impact, 37 resources were selected in the first list of GCBRs. One key feature of the GCBRs is that the data from these resources are available openly and can be accessed and used without restriction by researchers worldwide. PharmGKB is honored to be recognized as a Global Core Biodata Resource and we fully support GBC's mission to stabilize support for the global biodata infrastructure.

We would like to take this opportunity to thank all the present and past members of PharmGKB, our funding agencies, scientific advisors and collaborators, and especially our users, for their continued support and contribution to build this vital resource. PharmGKB serves both basic science investigators as well as clinicians and laboratories. Sustainable long-term support is critically important for us to provide stable, comprehensive, and dependable pharmacogenomic information to our users across the globe.

Wednesday, November 9, 2022

CYP2C18 and knowledge gaps

Pablo Zubiaur & Andrea Gaedigk have an editorial online ahead of print in Pharmacogenomics calling for the inclusion of CYP2C18 in more studies of drug metabolism [PMID: 36331025].

CYP2C18 is in a cluster on chromosome 10 that has CYP2C18, CYP2C19, CYP2C9 and CYP2C8 that spans 500k bases (NCBI gene browser). The authors comment that CYP2C18 is only included in three PharmGKB pathways (there are actually four: clobazam, diclofenac, warfarin and acenocoumarol), while the other genes of the CYP2C locus are in many. CYP2C19 and CYP2C9 have a volume of data annotated in PharmGKB, CYP2C8 is less populated and CYP2C18 has little (see table below). Similarly, CYP2C19, CYP2C9 and CYP2C8 have haplotypes in PharmVar, while CYP2C18 does not. As Zubiaur and Gaedigk discuss, there are comparatively very few PGx peer-reviewed papers about CYP2C18 and PharmGKB depends on these publications for annotations and pathway creation. We strongly agree with the authors that more studies regarding CYP2C18 would be valuable contributions to the field and look forward to curating them into PharmGKB as they are published.

Like many grant-funded projects, PharmGKB is a small team with limited resources and is unable to manually curate all of PubMed, so sometimes papers are published that we have not yet curated. We encourage PharmGKB users to contact us anytime if they identify important papers for us to curate. If users find knowledge gaps or have recommendations for additional pathway candidate genes, please send the relevant references to We also encourage users who are interested in collaborating on a drug pathway to contact us.

Thursday, October 20, 2022

PharmCAT Version 2.0 Released

Version 2.0 of the Pharmacogenomics Clinical Annotation Tool (PharmCAT) has been released October 20, 2022. PharmCAT is a software tool that takes the genetic data (VCF file) of an individual as input, interprets the pharmacogene alleles, diplotypes, and phenotypes, and generates a report with genotype-based drug prescribing recommendations. 

In version 2.0, we have made substantial improvements and changes to the tool based in part on user feedback. Below we outline these features and provide links to read more about each one. We have also slightly reorganized and expanded the documentation found on the PharmCAT website to better support users. 

We hope you will take a look and send any comments, questions or feedback to 

Major PharmCAT v2.0 features:
  • PharmCAT now includes available DPWG prescribing guidance (as annotated in the PharmGKB DB) in addition to CPIC recommendations. Read more about the genes and drugs included from DPWG and how they are sourced 
  • PharmCAT report has been redesigned for multiple recommendation sources 
  • Added functionality for research use only 
    • CYP2D6 diplotype calling based on SNPs and INDELs from a VCF file (does not include structural variants/CNVs). Warning: Because structural variation and haplotype can’t be determined from VCF, this functionality shouldn’t be used for clinical purposes. 
    • Partial and combination calls for novel combinations of PGx positions included in the PharmCAT allele definitions. This functionality helps users determine if a sample potentially contains a novel allele. 
  • Added support for the DPYD genotype based on the lowest activity score as described in CPIC’s fluoropyrimidine guideline (PMID: 29152729) for samples with more than two DPYD variants.
  • Extended support of external genotype/phenotype input (see input and output examples and outside call format). This functionality allows users to include genetic test results from other sources in PharmCAT’s report. 
  • Reworked PharmCAT command line tool/arguments. These changes are not backwards compatible with previous PharmCAT versions. 
  • VCF Preprocessor updates 
    • Harmonized the VCF preprocessor command line arguments and flags with PharmCAT
    • Unified the output file name patterns of the VCF preprocessor with what PharmCAT uses
    • Added a few amenities, e.g., bcftools and bgzip version check, switch to .bgz file suffix for clarity 
 The latest PharmCAT version and extensive documentation is available on

Tuesday, October 4, 2022

There is no ontology term for Phenoconversion in BioPortal

There are two papers ahead of print in Pharmacogenomics both discussing how important phenoconversion is to consider in the implementation of PGx in clinical practice. Phenoconversion in the PGx context is a drug-drug interaction that impacts a drug metabolizing phenotype such that it mimics the effects of a metabolizer genotype. Yet there was no match for phenoconversion in a search of BioPortal (on 10/3/2022) which has over a thousand biomedical ontologies including MeSH, MedDRA, RxNorm and other ones we use for PGx. PharmGKB does collect drug-drug interaction information from drug labels and publications that can potentially be used in the future to help account for phenoconversion. However, while phenoconversion is a well-known phenomenon, the specifics of how phenoconversion affects patient phenotype, especially on top of genotype, has not been quantified (to our knowledge). This makes it difficult to apply drug-drug interaction information to predict how patient genotype-to-phenotype mapping should be altered by information about concomitant drugs the patient takes when using prescribing guidance from CPIC, DPWG or FDA.

Paper 1: Pharmacogenomics in psychiatry - the challenge of cytochrome P450 enzyme phenoconversion and solutions to assist precision dosing. Mostafa S, Polasek TM, Bousman CA, Müeller DJ, Sheffield LJ, Rembach J, Kirkpatrick CM.Pharmacogenomics. 2022 Sep 28:0. doi: 10.2217/pgs-2022-0104. Online ahead of print. [PMID: 36169629]

This review proposes a model for improved clinical decision support that integrates genomics, co-prescribing information, lifestyle and disease factors into precision dosing. Excerpt from the paper: “In psychiatry, the proposed CDSS (Clinical decision support system) powered by MIPD (model-informed precision dosing) would apply precision dosing of psychotropics by accounting for the influence of genetic variations in CYPs; the presence of CYP phenoconversion; and coexisting lifestyle (smoking), pregnancy or disease (cancer) factors…. In this study, clozapine concentrations were better predicted by MIPD accounting for the CYP1A2 inducing effect in smokers homozygous for the CYP1A2*1F allele. This is an example of where environmental (smoking) and PGx (CYP1A2 genotype) factors were used to optimize the MIPD model, resulting in improved predictions of clozapine plasma concentrations. In principle, this approach can be applied across other psychotropics, especially those with a high risk of toxicity in overdose (e.g., tricyclic antidepressants).”

Paper 2: The importance of phenoconversion when using the CYP2D6 genotype in clinical practice. Cicali EJ, Wiisanen K.Pharmacogenomics. 2022 Sep;23(14):749-752. doi: 10.2217/pgs-2022-0087. Epub 2022 Sep 14. [PMID: 36102178]

This is an editorial with a case study describing a patient with chronic pain taking tramadol (among other medications). The patient is then started on an antidepressant and the pain is no longer relieved even at higher doses. Even though the patient tests as a CYP2D6 normal metabolizer the antidepressant fluoxetine has resulted in phenoconversion and clinically the patient now responds as a CYP2D6 poor metabolizer with respect to tramadol. They discuss options to change the antidepressant or the pain therapies. The authors caution that “CYP2D6 genetic test results should be continually evaluated in the light of concomitant medications throughout a patient’s lifetime.”

Searching PubMed to see the impact of phenoconversion is complicated as this word is also used to describe change or evolution of disease phenotypes, but the results by year tracker shows exponentially increased use. A phenoconversion tag specific for drug interaction related phenoconversion, would help people in PGx research identify the relevant papers.

Maybe phenoconversion could be added as a child term to MedDRA under Drug-drug pharmacokinetic interaction?

Monday, September 26, 2022

New tutorial and walkthrough videos now available

We are pleased to announce the release of our PharmGKB walkthroughs and tutorial videos on YouTube. Users can now view detailed video walkthroughs of each of the main annotation types on PharmGKB as well as a longer video combining resources from across the site. We have also produced a series of tutorial videos to help users learn more about key concepts and issues in pharmacogenomics. These videos range from an introduction to the field to an explanation of the star allele nomenclature system for haplotypes. The videos are freely available on the PharmGKB YouTube channel. Links can also be found on our Educational Resources page

Thursday, September 22, 2022

PharmGKB and Reactome collaborate on two pathways

PharmGKB has collaborated with Reactome for two new pharmacokinetics pathways, Ribavirin, and Prednisone and Prednisolone available via both formats:

Ribavirin Pathway, Pharmacokinetics 

Prednisone and Prednisolone Pathway, Pharmacokinetics 

Monday, August 29, 2022

Study of vitamin K pathways presents potential new warfarin candidates

Almost two decades after the cloning of VKORC1 and association with warfarin dose, a new pathway of vitamin K cycling has been published. Mishima et al [PMID:35922516] report on the Ferroptosis suppressor protein 1 (FSP1), coded for by the AIFM2 gene, and its mechanism of maintaining vitamin K in the hydroquinone form. While not interacting directly with warfarin, AIFM2 may play a role in vitamin K-related branches in the warfarin PD pathway that warrant investigation for PGx. 

A review of several ferroptosis related proteins (Vabulas, 2021) discusses some variants of AIFM2. The review mentions a functional study of E156A in the FAD cofactor binding domain that found it impaired anti-ferroptotic activity. This variant is not found in dbSNP. A different amino acid change, E156D (rs1272224219C>A), has not been observed in the ALFA populations that dbSNP reports on, while yet another amino acid change, E156V (rs760393626T>A), is extremely rare (found in 1/121216 alleles). The review lists 2 other potential AIFM2 candidates for functional investigation which are more frequently observed: M135T (mapped by PharmGKB to rs10999147A>G) and D288N (mapped to rs2271694C>T).

(Edited 9/20/22) The Warfarin Pathway, Pharmacodynamics has been updated to include the new candidate gene.

Friday, July 29, 2022

PharmVar GeneFocus paper for SLCO1B1 is published

The PharmVar GeneFocus: SLCO1B1 paper has just been published by Clinical Pharmacology & Therapeutics.


This review provides a general overview of SLCO1B1 as well as a deeper dive into its nomenclature. This GeneFocus covers genetic variability, functional impact, clinical relevance, gene nomenclature before and after PharmVar updates, methods for allele characterization and how the new nomenclature impacts pharmacogenetic testing and interpretationSpecific details of changes to allele definitions can be found on the PharmVar SLCO1B1 page and on the Change Log tab of the SLCO1B1 Allele Definition Table available from PharmGKB. This new nomenclature has been used in the recently published CPIC guideline on statin-associated musculoskeletal symptoms.


For more details, please see:

PharmVar GeneFocus: SLCO1B1

Clin Pharmacol Ther. 2022 Jul 7. doi: 10.1002/cpt.2705. 

Laura B. Ramsey, Li Gong, Seung-been Lee, Jonathan B. Wagner, Xujia Zhou, Katrin Sangkuhl, Solomon M. Adams, Robert J. Straka, Philip E. Empey, Erin C. Boone, Teri E. Klein, Mikko Niemi, Andrea Gaedigk.

PMID: 35797228

Friday, July 22, 2022

CYP2A6 now released on PharmVar

PharmVar and PharmGKB are excited to share that CYP2A6 has been transitioned into the PharmVar database. CYP2A6 metabolizes several substates including coumarin, nicotine, aflatoxin B1, nitrosamines, and some pharmaceuticals. Owing to its highly polymorphic nature, CYP2A6 activity varies considerably between individuals. Due to the complex nature of the CYP2A gene locus that contains not only CYP2A6, but also the highly similar CYP2A7 and CYP2A13 genes, CYP2A6 genotype analysis and characterization of allelic variants is not trivial. It is therefore of utmost importance to have up-to-date information regarding sequence variation and star allele (haplotype) definitions to facilitate accurate genetic testing, data interpretation and phenotype prediction in the research and clinical settings.  

The PharmVar CYP2A6 gene experts have systematically reviewed and curated all star allele definitions that were previously issued by the CYP450 Nomenclature databases (these were last updated in 2014 and can be accessed through the archive). Some notable changes include:

  • Variants and star alleles are now defined using the most current genomic reference sequence
  • Several alleles have been merged, revised and/or redesignated (legacy allele designations are cross-referenced)
  • Regions used for allele definitions have been updated
  • Structural variants including a common conversion at the 3’UTR have been updated to current knowledge and are detailed in the ‘Structural Variation’ document.

Changes made are detailed in the ‘Change Log’ document and other important information about CYP2A6 and the information displayed by PharmVar can be found in the ‘Read Me’ document. All accompanying documents can be accessed at the PharmVar CYP2A6 page at 


Since there are no CPIC guidelines for CYP2A6, the PharmVar CYP2A6 page does not provide information for ‘CPIC clinical function’. The expert panel has, however, compiled a table in the ‘Read Me’ document summarizing function information for selected star alleles.  


Lastly, we would like to thank the PharmVar CYP2A6 experts Rachel Tyndale, Alec Langlois, Meghan Chenoweth, Giada Scantamburlo, Charity Nofziger, David Twesigmwe, Rachel Huddart and Andrea Gaedigk for their tireless efforts that made this massive update possible.

Tuesday, June 21, 2022

Clinical Genomics Career Panel webinar series 2022

ClinGen is hosting a Clinical Genomics Career Panel webinar series this summer for individuals interested in career in clinical genomics. Sessions are moderated and panel members will discuss their work and career paths. All are welcome to join!

PharmGKB Acyclovir/Ganciclovir Pathway Published

The PharmGKB Acyclovir/Ganciclovir Pathway has recently been published in the journal Pharmacogenetics and Genomics.

Acyclovir (ACV) and ganciclovir (GCV) are commonly prescribed antivirals to treat infections caused by herpes viruses, varicella-zoster virus or cytomegalovirus (eg. cold sores, shingles and chicken pox, etc.). The pathway, co-developed by Maud Maillard along with other members of the Yang Lab in St. Jude, as well as members of the PharmGKB team, outlines the metabolism, transport, and mechanism of action of ACV and GCV with a view to decipher the existing interpatient variability, and highlights pharmacogenomics implications by the variants of the NUDT15 and ABCC4 genes on ACV and GCV efficacy.  Further work is needed to validate these findings and discover other candidates, with the aim of optimizing antiviral therapy.


View the interactive pathway on PharmGKB:
Acyclovir/Ganciclovir Pathway, Pharmacokinetics/Pharmacodynamics


Read our new publication:

PharmGKB summary: acyclovir/ganciclovir pathway
Maud Maillard, Li Gong, Rina Nishii, Jun J Yang, Michelle Whirl-Carrillo, Teri E Klein
Pharmacogenet Genomics. 2022 Jul 1;32(5):201-208. Epub 2022 May 30.

PMID: 35665708

View all pathways on PharmGKB.

Thursday, June 2, 2022

Expansion of pharmacogenetics education agreed as part of lawsuit settlement

Oregon Health & Science University (OHSU) will introduce new educational initiatives on the risks of prescribing the chemotherapy drug capecitabine to patients with DPD deficiency as part of a lawsuit settlement.

The settlement was reached with Joanne McIntyre, whose husband David died as a result of severe capecitabine toxicity. David carried variations in the gene DPYD, which encodes the DPD enzyme. DPD is involved in metabolism of fluoropyrimidine drugs, including capecitabine. Variants in DPYD, such as those that David carried, can inactivate the DPD enzyme, leading to DPD deficiency. Patients with DPD deficiency are unable to properly metabolize capecitabine and other fluoropyrimidines, and are at risk of experiencing severe drug toxicity. In David's case, this toxicity was fatal.

PharmGKB has annotations of several clinical guidelines for capecitabine and DPYD, including those from CPIC and the DPWG. These guidelines uniformly recommend either a dose reduction or selection of an alternative drug in patients with DPD deficiency.

OHSU will hold seminars to educate clinicians on the risks associated with DPD deficiency, how to identify severe capecitabine toxicity in patients and how to administer the antidote. They will also include a module on the topic in their fellowship program and provide a written resource guide to staff in their oncology department. Going forward, patients identified as candidates for capecitabine chemotherapy will be informed of the risks associated with DPD deficiency and, where appropriate, will be offered testing.

We at PharmGKB applaud Joanne's singular dedication to saving patients' lives and OHSU's commitment to implement these changes. Resources on capecitabine pharmacogenomics, including annotations on clinical guidelines for the use of DPYD genotypes in capecitabine prescribing, can be found at the PharmGKB capecitabine drug page.

Thursday, May 19, 2022

Update to PharmGKB Pediatric Summaries - BPCA Drugs

The latest round of PharmGKB’s pediatric drug summaries is now live on PharmGKB pediatric. This release includes summaries for 55 drugs, bringing the total summary count to over 180, now including all drugs on the Best Pharmaceuticals for Children Act (BPCA) priority list in addition to all CPIC guideline drugs.

Drugs with new summaries include:
  • Alfentanil
  • Amiodarone
  • Ampicillin
  • Azithromycin
  • Bosentan
  • Cidofovir
  • Ciprofloxacin
  • Clindamycin
  • Clonidine
  • Dexmedetomidine
  • Digoxin
  • Doxycycline
  • Furosemide
  • Granisetron
  • Griseofulvin
  • Heparin
  • Hydralazine
  • Hydrochlorothiazide
  • Hydromorphone
  • Hydroxycobalamin
  • Hydroxyurea
  • Isotretinoin
  • Labetalol
  • Levofloxacin
  • Levothyroxine
  • Lidocaine
  • Lisinopril
  • Lithium
  • Lorazepam
  • Lurasidone
  • Meropenem
  • Metformin
  • Methylprednisolone
  • Midazolam
  • Molindone
  • Nafcillin
  • Nicardipine
  • Nifedipine
  • Nifurtimox
  • Olanzapine
  • Pentobarbital
  • Piperacillin-Tazobactam
  • Pralidoxime
  • Prednisolone
  • Sertraline
  • Sildenafil
  • Spironolactone
  • Terbutaline
  • Timolol
  • Topiramate
  • Tranexamic Acid
  • Valganciclovir
  • Vancomycin
  • Vecuronium

Monday, May 16, 2022

Response to the American Academy of Pediatrics' Statement "Eliminating Race-Based Medicine"

On May 2nd, the American Academy of Pediatrics (AAP) released a pre-published policy statement titled “Eliminating Race-Based Medicine,” noting that race is a “historically derived social construct that has no place as a biologic proxy.” The statement provides necessary and meaningful commentary on “the medical field’s history of inaccurate applications of race correction and adjustment factors” and calls for the overdue elimination of race-based medicine. We at PharmGKB applaud this statement and believe it is important to engage with this call as pharmacogenomics professionals who urge for the implementation of personalized medicine.

Looking forward in research, there is an urgent need to direct research efforts towards underserved populations to address the issues of health disparities. Additionally, clinical implementation of pharmacogenomics needs the development of truly race-agnostic dosing guidelines and algorithms.

The terms ‘race,’ ‘ethnicity,’ and ‘ancestry’ tend to be used interchangeably when discussing a person’s origins. However, there are distinct differences in their meanings. Race and ethnicity are generally accepted to be social and cultural constructs, respectively, and are not typically assigned based on the genetic information of patients. By comparison, ancestry is a biological construct rooted in genetics.

Race or ethnicity are typically disclosed via self-report at the discretion of the patient or visual assignation by a third party (e.g. clinician, healthcare administrator) and, as such, have little grounding in genetics. The assignment of race or ethnicity also brings significant socio-economic implications which are inherent to the use of these constructs. Moreover, it is an inadequate proxy for genetic ancestry that carries additional complications for transracial adoptees and multiracial patients, among others.

PharmGKB notes that the AAP’s recommendation that “professional organizations and medical specialty societies should identify and critically examine organizational policies and practice guidelines that may incorporate race or ethnicity as independent variables or modifying factors” is a relevant and current point of consideration within pharmacogenomics.

In 2018, PharmGKB replaced the Office of Management and Budget Standards (OMB) race and ethnicity categories used in their curation efforts with a biogeographical grouping system [PMID: 30506572]. While PharmGKB serves as a global resource, these OMB groups are US-centric and, as socio-cultural measures of identity, lack the capacity to capture the scale of global human diversity. The use of these biogeographical groups is intended to standardize and to ensure consistency in communications regarding the variability of pharmacogenetic allele frequencies.

Pharmacogenomics, like other areas within genetics, is impacted by the homogeneity of reference genomes. When dosing algorithms and polygenic risk scores are developed primarily in patients of one ancestry (typically European), differences in allele frequencies across populations may prevent these tools from benefiting populations not represented in the reference data. It’s important to recognize that individual medical experiences are shaped by many different factors, including genetic, socio-economic and geographical and that the collective experience of an underrepresented ancestry or ethnic population is likely to be overlooked or diminished by a relative lack of research in these groups. A greater focus on research in underrepresented populations is crucial to understanding how medical experiences can and do vary between communities, and allows us to meet and address a wider variety of medical needs. In terms of implementation of pharmacogenetic guidance, no study population can fully characterize an individual. 

Almost all CPIC guidelines are ancestry-agnostic. However, there is an exception with a complex history worth addressing, as well as a good example of the importance of expanding allele frequency research. Seminal work in warfarin pharmacogenomics focused on testing for CYP2C9*2 and *3, which are found at a frequency of 13% and 7.5% (respectively) in populations of European ancestry, with other alleles present at <1%. In populations of African ancestry, CYP2C9*2 and *3 alleles are instead found at a frequency of around 1-2% - the highest frequency reduced-function variant in this population is *8, and *5, *6, and *11 are also found at around or over 1% frequency (see the CYP2C9 allele frequency table). As such, in studies or implementation where only *2 and *3 were tested for, patients of African ancestry with these other alleles were likely not identified, and instead they were assigned a *1/*1 diplotype. This has resulted in confusing results, patients who unexpectedly required a decreased dose of warfarin, and reduced confidence in the capacity for genotyping to have the desired effect for the patients’ clinical response. Because of this, the CPIC guideline for CYP2C9, CYP4F2, VKORC1, and warfarin chose to stress the importance of testing for these alleles in populations with African ancestry. 

Yet, these alleles are not absent in other populations, and this approach also fails to acknowledge that patients with mixed ancestry may not identify as of African descent and that some patients may not know whether they have African ancestry. The CPIC guideline does provide optional guidance for patients without African ancestry with CYP2C9*5, *6, *8, and/or *11 that is similar to the guidance provided for patients with African ancestry, but only for patients who already have information for these alleles - and does not include recommendations for testing for these alleles in patients without African ancestry.

Currently, these alleles do not have differing effects based on the patient’s ancestry - the distinction is in the frequency, not the clinical implementation. Testing every patient for these alleles would be beneficial, even if only to catch the few patients in other populations and those with multiple or uncertain ancestries who also carry these alleles. It is, after all, called personalized medicine.

The CPIC guideline also refers specifically to the SNP rs12777823 in recommendations for African-American patients only (not all patients of African ancestry). This is the only guideline where it states not to use a genetic result in some individuals - “the data do not suggest an association between rs12777823 genotype and warfarin dose in non-African Americans, thus rs12777823 should not be considered in these individuals (even if available).”

This SNP is found across all populations (according to gnomAD v2.1.1), and has been stated to affect warfarin response in African-American patients [PMID: 26024874] [PMID: 26877068] [PMID: 28686080]. The mechanism by which this SNP affects warfarin response is unknown - the SNP is intergenic, but close to CYP2C18, and is largely assumed to be a marker in linkage disequilibrium (LD) with something else [PMID: 23755828]. While further study is needed, it’s unlikely that this SNP itself has a function in people of one genetic ancestry but not in others, and more likely that the frequency of LD with a mechanistic variant varies by populations. 

This call for race-agnostic pharmacogenetic clinical implementation is not limited to warfarin - several papers have been published discussing the U.S. Food & Drug Administration’s use of race as a limitation in recommendations for pharmacogenetic testing related to carbamazepine and allopurinol [PMID: 18840252] [PMID: 33492362]. This conversation is not a new one - from letters of support arguing against use of race to determine whether it is appropriate to test patients for HLA variants prior to initiating allopurinol therapy [PMID 30383575] to responses validating race-agnostic approaches to HLA genotyping [PMID: 30383576].

In summary, PharmGKB applauds the AAP’s statement calling for the elimination of race-based medicine. It is critical for the field of pharmacogenomics to examine how we can incorporate race-agnostic approaches to PGx implementation while acknowledging the critical importance of research in diverse populations to identify crucial PGx variants. Race-agnostic PGx implementation has the potential to meet a wider variety of individual medical needs, particularly with respect to underrepresented populations and those patients with non-monolithic ancestry, and it continues to be critical from a scientific standpoint to further expand our understanding of allele frequencies beyond Eurocentric frames of reference.

(For those interested in learning more, ClinGen’s Ancestry and Diversity working group, in collaboration with ELSIhub, are currently running a series of conversations on populations descriptors (i.e., race, ethnicity, and ancestry), and several of the speakers have pointed to the distinctions between these terms, particularly with respect to clinical genetics.)

Teri E. Klein (Principal Investigator of PharmGKB, CPIC, PharmCAT, and Stanford ClinGen)
Michelle Whirl-Carrillo (Co-Principal Investigator and Director of PharmGKB)
Li Gong
Rachel Huddart
Ingrid Keseler
Clarissa J. Klein
Binglan Li
Caroline F. Thorn
Matt W. Wright (Director, Stanford ClinGen)
Mark Woon

Wednesday, May 4, 2022

Ask a Curator for Healthcare Professionals on June 7th

We are holding an Ask a Curator zoom targeted towards healthcare professionals wanting to learn more about PharmGKB and pharmacogenomics. This is part of NHGRI’s Healthcare Professionals Genomics Education Week (#MedGeneEd22). Be sure to spread the word to colleagues who may find this useful.

We are asking people to please register in advance with their questions so curators can better focus these events. There will also be the opportunity to ask questions during the event. Events will be limited to 25 participants to allow enough time for everyone’s questions to be answered.

Sign up here for Tuesday June 7th at 12pm EST, 9am PST, 5pm GMT
Want to be notified about future Ask a Curator events? Join our mailing list here.

Thursday, April 21, 2022

What does *1 really mean? And why does that matter?

A Haiku about PGx for National Poetry Month.

Diagnosed star one,

Yet severe toxicity.

What did the lab test?

What does *1 really mean? And why does that matter?

The star alleles of the drug metabolizing enzyme genes are an unusual way of defining variation and are perhaps one of the most misunderstood aspects of pharmacogenomics. Arising from attempts to describe and standardize the molecular basis of different drug phenotypes; debrisoquine poor metabolizer phenotype, etc [PMID: 7773298, PMID: 8807658].  Sometimes authors use the term “wild type”, even for humans, to describe the most common form of the gene or protein in a given population where it displays the expected drug metabolism phenotype. The *1 allele is generally used to denote the absence of the variants tested. However, it is not a stable assignment; a *1/*1 individual only tested at one locus may not have the same genetic sequence as a *1/*1 individual tested for a panel of 10 variants in the same gene. This really matters when evaluating the likelihood of drug phenotype - the "reference" is only as good as the number of variants that were checked. *1 is rather a placeholder, it is the absence of certainty, because even with a panel that covers variants that represent 99% of known variation (in the populations examined so far which are not representative of the full global population) there may still be rare variants with significant impact on protein function that we may not yet have documented. While a *1/*1 may not be at increased risk of toxicity (or other phenotypes), or require a change of dosage immediately, they still have the baseline level of risk and it shouldn’t be a huge surprise if they exhibit an adverse reaction to a drug. 

Recent publications of case studies that concluded a lack of involvement of known pharmacogenes without documenting what was tested: 

PMID:35180762 - “Acral Skin Rash Caused by Altered Mercaptopurine

Metabolism in Maintenance Therapy for B-Cell

Acute Lymphoblastic Leukemia”  excerpt “TPMT and NUDT15 genotype at diagnosis were wildtype alleles and therefore we started with full 6-MP dosing.”

This issue is not limited to pharmacogenes using star allele nomenclature: “5-Fluorouracil Neurotoxicity in the Absence of Dihydropyrimidine Dehydrogenase Deficiency Case Report” [PMID:35419161] excerpt “Our patient tested negative for DPD mutations, but it remains possible she harbored a genetic variant not accounted for in the genetic testing panel. Other known risk factors include mutations in the orotate phosphoribosyltransferase and thymidylate synthase genes… “

We recommend authors always include the list of all variants that were tested, and other features see [PMID:30406943].

Thursday, April 14, 2022

Update to PharmGKB Pediatric Drug Summaries

The third round of PharmGKB's pediatric drug summaries is now live on PharmGKB pediatric. This release includes over 20 additional drugs with a focus on those on the Best Pharmaceuticals for Children Act (BPCA) priority list, including:

These pediatric drug summaries contain key information relevant to prenatal, postnatal, and pediatric populations, manually curated from PharmGKB annotations, pathways, CPIC guidelines, and FDA-approved drug labels.

PharmGKB continues to add to the list of drugs with pediatric summaries.

Wednesday, April 6, 2022

"Ask a Curator" live zoom event

PharmGKB curators will hold a series of live Q&A events over Zoom to help people find and use different aspects of the knowledgebase. We hope this will be a great way to answer questions about PharmGKB and PGx which are specific to users’ individual needs or projects.  These events will demonstrate the full extent of the resources available on PharmGKB, as well as details about those resources and how to download, use, and cite data from PharmGKB. 

In order to tailor these events for users with similar needs from PharmGKB, the first event will focus on researchers. Future events geared towards educators and clinicians are in the works, as well as events hosted at different times for our global audience. We will also be recording this upcoming event along with future events for those who are unable to attend live. Recordings will be posted on the PharmGKB YouTube channel.

We are asking people to please register in advance with their questions so curators can better focus these events. There will also be the opportunity to ask questions during the event. Events will be limited to 20 participants to allow enough time for everyone’s questions to be answered.

Sign up here for Tuesday April 26th at 12pm EST, 9am PST, 5pm GMT

Can’t make it but want to sign up for a future Ask a Curator? Join our mailing list here.