Drug Metabolism Test

About this Test

Indications for TestingPharmacogenetics brochure cover

How to Order the Test

Specimen Type

Cost and CPT Codes

Turnaround Time

Results Reporting

Test Methodology

Interpretation of Results

Resources and Education

Future Test Updates

Helpful Websites


About this Test

The Iowa Institute of Human Genetics (IIHG) offers an integrated pharmacogenomics test called the Drug Metabolism Test (DMT). This test and the associated analysis pipeline were developed by the IIHG in collaboration with the University of Iowa Hospitals and Clinics (UIHC) Department of Pharmaceutical Care and University of Iowa College of Pharmacy to facilitate improved and personalized medication selection. Determining a patient’s DNA profile  for genes important in drug metabolism may guide drug selection and dosage thereby minimizing the risk of harmful side-effects.

The test can be ordered preemptively or at the point of care to guide health care management. Prescribers can elect to order only a subset of the panel (e.g., cancer related drugs) or the entire panel. Results will be returned to the ordering health care provider. A Pharmacogenomics (PGx) Outpatient Clinic has been established at UIHC to serve your patient’s needs.

The DMT is focused on genes associated with adverse drug responses to:

  • Anti-clotting drugs
  • Cancer-related drugs
  • Immunosuppressants
  • Opioids
  • Infectious disease drugs
  • Neurology/Psychiatry drugs

Indications for Testing

 

How to order the Test

  1. This test must be ordered by a health care provider. Please note patients are not permitted to order the test.
  2. Complete the PDF iconDrug Metabolism Test Requisition Form.pdf
    • UIHC health care providers should complete a PDF iconDrug Metabolism Test requisition form and place a test order as a Miscellaneous Test in Epic - titled ‘Drug Metabolism Test’. This is a send out test.
    • Health care providers outside of the University of Iowa Hospitals and Clinics may order the test by mailing the completed PDF iconDrug Metabolism Test requisition form and sample to the address listed below. 
  3. See Specimen Type for sample collection information.
  4. After collection, samples should be stored and shipped at room temperature.
  5. Delivery: will receive Monday-Friday

IIHG Clinical Diagnostic Division

285 Newton Road, 5292 CBRB

Iowa City, IA 52242

Phone: 319-335-3688


Specimen Type

* All samples must be labeled with the patient's name, date of birth, and date of collection.

  • 6 mL whole blood in lavender EDTA tube (3 mL pediatric minimum). Samples must be received within 72 hours of sample collection.

OR

  • 10 µg DNA (A260/A280 1.8-2) resuspended in 0.1mM EDTA (10mM Tris HCl, 0.1mM EDTA, pH 8, Teknova Cat# T0220)

After collection, samples should be stored and shipped at room temperature.

Please note: If insufficient quality or quantity of DNA is obtained, an additional sample will be requested. Incorrect handling or shipping of specimens can result in insufficient quality or quantity of DNA.


Cost and CPT Codes

  • Your institution will be billed $495 for this test. The IIHG will NOT submit to insurance or bill patients directly. Insurance may, or may not, cover this test. Please check with the patient's insurance provider for current coverage.
  • The IIHG accepts institutional billing, Visa and MasterCard.

Please note: billing information MUST be completed before samples will be processed.


Turnaround Time

Contact us at iihg@uiowa.edu or 319-335-3688


Results Reporting  

  • Result reports will be returned to the referring health care provider(s) indicated on the test requisition.

  • Result reports have been developed in collaboration with UIHC physicians and pharmacists and educational materials are incorporated into the report to aid health care providers in the interpretation of results. The IIHG can provide education materials and assistance to the health care provider so he/she may counsel the patient with confidence.

  • If assistance is needed to interpret the results, please contact the IIHG at 319-335-3688 or iihg@uiowa.edu, and we will respond within one business day.


Test Methodology

  • Targeted sequence capture followed by massively parallel sequencing using the IIHG PGx xGen® Lockdown® Probes and the Illumina MiSeq sequencer to detect DNA variations in CYP2C19, CYP2D6, CYP3A5, DPYD, G6PD, TPMT, UGT1A1.
  • A custom in-house informatics analysis pipeline has been developed to translate DNA variants to a patient's drug metabolizer status.
  • Only variants with a known metabolizer status and clinical recommendations are reported. Novel variants are not analyzed or reported.
  • Data sensitivity and specificity for testing is >99.9%. Pharmacogenomic DNA variants are covered at our depth-of-coverage minimum threshold (30 reads). In general, >99% of single nucleotide variant calls and small insertion/deletion variant calls are confirmed when compared to an orthogonal technology.
  • Reported single nucleotide variants and copy number variants in CYP2D6 (e.g., CYP2D6*5 are confirmed by an orthogonal technology (such as Sanger Sequencing or TaqMan Assay).

Interpretation of Results 


Technical Limitations 

  • It is not known how all medications are metabolized.

  • This test is based on targeted sequence capture technology; regions not captured are not interrogated.

  • This assay is designed to amplify specific allelic variants of CYP2D6, CYP2C19, CYP3A5, DYPD, G6PDTPMT, or UGT1A1. Mutations in other areas of these genes are not detectable with this assay. Only variants with clinical recommendations are analyzed and reported. Based on our analysis pipeline we will not find variants that do not have clinical recommendations (CPIC). As a result, your patient may carry a DNA variant that we will not be detected on this test.

  • The absence of a reportable variant in a given gene does not mean there are not pathogenic variants in that gene.

  • The variant(s) causing a patient's altered drug metabolism may not be detected because: some types of variants are very difficult to identify; the variant may not be included in the sequenced/studied region, or the variant may not have clinical recommendations.


Resources and Education

  • The IIHG Pharmacogenomics Team includes physicians, pharmacists and a genetic counselor.
  • The IIHG Pharmacogenomic Team can assist you with the following:
    • Answer any questions regarding ordering the IIHG Drug Metabolism Test
    • Understanding the result report and interpretation
    • Questions about other medications that may be altered based on your patient’s results
  • To contact the IIHG Pharmacogenomic Team:

Phone: 319-335-3688

Email: iihg@uiowa.edu

  • To learn more about drug metabolism, please check back soon for health care provider education resources, including upcoming courses, seminars, or grand rounds presentations.
  • If you would like to schedule an educational event for your department, please contact the IIHG at 319-335-3688 or iihg@uiowa.edu.
  • To request patient education brochures for your clinic please contact us at iihg@uiowa.edu.

Future Test Updates 

Please let us know if there is a medication you would like the IIHG to include on future versions of this test.


Helpful Websites

Clinical Pharmacogenetics Implementation Consortium (CPIC):

  • Peer-reviewed clinical guidelines published by PharmGKB and the Pharmacogenomics Research Network

Genetics Home Reference

  • Information about how genes affect your health: what genes are, how they work, and how they can cause illnesses

The Pharmacogenomics Knowledgebase

  • Information about how genes interact with medication

Contact Information 

Iowa Institute of Human Genetics

University of Iowa  

285 Newton Road, 5292 CBRB

Iowa City, IA, 52242

Telephone: 319-335-3688

Fax: 319-335-3484  

Email: iihg@uiowa.edu

www.medicine.uiowa.edu/humangenetics