Ya-Feng Wen1, Kathleen A Culhane-Pera2, Bharat Thyagarajan3, Jeffrey R Bishop1,4, Heather Zierhut5, Muaj Lo2, Txia Xiong2, Kerui Peng1, Katherine Holzer6, Koobmeej Lee2, Robert J Straka1. 1. Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota. 2. Minnesota Community Care, St. Paul, Minnesota. 3. Department of Laboratory Medicine and Pathology, School of Medicine, University of Minnesota, Minneapolis, Minnesota. 4. Department of Psychiatry, School of Medicine, University of Minnesota, Minneapolis, Minnesota. 5. Department of Genetics, Cell Biology and Development, College of Biological Science, University of Minnesota, Minneapolis, Minnesota. 6. CentraCare Genetics Clinic, St. Cloud, Minnesota.
Abstract
OBJECTIVES: Implementing pharmacogenetics for very important pharmacogenes (VIPs) holds the promise of improving clinical outcomes through optimal medication selection and dosing. However, significant differences in the frequency of actionable variants in VIPs may exist within subpopulations of a given ancestral group. Furthermore, these differences can potentially impact drug selection and dosing. The purpose of this study was to ascertain allele frequencies for VIPs and to predict medication requirements using Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines in Hmong and compare with published data for East Asians. METHODS: Using a community-based participatory action research approach, DNA collected from 194 Hmong adults living in the United States was analyzed for 22 genetic variants within eight VIPs (CYP2C9, CYP2C19, CYP4F2, DPYD, G6PD, SLCO1B1, TPMT, VKORC1). Allele frequencies for VIPs and predicted medication requirements using CPIC guidelines were compared between Hmong participants and East Asians. RESULTS: Significant differences in allele frequencies between the Hmong and East Asians were found for 23% (5/22) of the CPIC-actionable variants tested. Allele frequencies for VIPs in Hmong versus East Asians were 16.6% versus 3.4% in CYP2C9*3A, 42.2% versus 29.0% for CYP2C19*2, 0.3% versus 8.3% in CYP2C19*3, 6.5% versus 22.1% in CYP4F2*3, and 3.6% versus 0.1% in SLCO1B1*5, respectively. These differences significantly influenced predicted medication usage recommendations in warfarin, simvastatin, and phenytoin between Hmong and East Asians. CONCLUSIONS: Important differences in allele frequencies for key genetic variants influencing selection of medications and dosages were found between the Hmong and East Asians. The magnitude and nature of these differences can be expected to result in different medication recommendations for the Hmong relative to East Asians.
OBJECTIVES: Implementing pharmacogenetics for very important pharmacogenes (VIPs) holds the promise of improving clinical outcomes through optimal medication selection and dosing. However, significant differences in the frequency of actionable variants in VIPs may exist within subpopulations of a given ancestral group. Furthermore, these differences can potentially impact drug selection and dosing. The purpose of this study was to ascertain allele frequencies for VIPs and to predict medication requirements using Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines in Hmong and compare with published data for East Asians. METHODS: Using a community-based participatory action research approach, DNA collected from 194 Hmong adults living in the United States was analyzed for 22 genetic variants within eight VIPs (CYP2C9, CYP2C19, CYP4F2, DPYD, G6PD, SLCO1B1, TPMT, VKORC1). Allele frequencies for VIPs and predicted medication requirements using CPIC guidelines were compared between Hmong participants and East Asians. RESULTS: Significant differences in allele frequencies between the Hmong and East Asians were found for 23% (5/22) of the CPIC-actionable variants tested. Allele frequencies for VIPs in Hmong versus East Asians were 16.6% versus 3.4% in CYP2C9*3A, 42.2% versus 29.0% for CYP2C19*2, 0.3% versus 8.3% in CYP2C19*3, 6.5% versus 22.1% in CYP4F2*3, and 3.6% versus 0.1% in SLCO1B1*5, respectively. These differences significantly influenced predicted medication usage recommendations in warfarin, simvastatin, and phenytoin between Hmong and East Asians. CONCLUSIONS: Important differences in allele frequencies for key genetic variants influencing selection of medications and dosages were found between the Hmong and East Asians. The magnitude and nature of these differences can be expected to result in different medication recommendations for the Hmong relative to East Asians.