BACKGROUND: CYP3A4, CYP3A5 and CYP3A7 are hepatic enzymes that metabolize about 50% of drugs on the market, with a large overlap in their specificities. We investigated the genetic bases that contribute to the variation of CYP3A activity. METHODS: We phenotyped 251 individuals from two independent studies (182 patients treated with methadone and 69 patients with clozapine) for CYP3A activity using the midazolam phenotyping test and genotyped them for CYP3A4, CYP3A5, and CYP3A7 genetic variants, including the single nucleotide polymorphism (SNP) rs4646437C>T in intron 7 of CYP3A4. Owing to the fact that CYP enzymes require electron transfer through the P450 oxidoreductase (POR), and functional impairment has been shown for the POR*28 SNP, this polymorphism was also analysed. RESULTS: We show that CYP3A4, CYP3A5 and CYP3A7 genotypes, including the SNP rs4646437C>T, do not reflect the inter-individual variability of CYP3A activity (P>0.1). In contrast, POR*28 TT genotype presents a 1.6-fold increase in CYP3A activity compared with POR*28C carriers (n = 182, P = 0.004). This finding was replicated in the second independent dataset (n = 69, P = 0.04). CONCLUSION: The SNP POR*28 seems to be a better genetic marker of the variability of total CYP3A activity in vivo than CYP3A4, CYP3A5 and CYP3A7 genetic variants.
BACKGROUND:CYP3A4, CYP3A5 and CYP3A7 are hepatic enzymes that metabolize about 50% of drugs on the market, with a large overlap in their specificities. We investigated the genetic bases that contribute to the variation of CYP3A activity. METHODS: We phenotyped 251 individuals from two independent studies (182 patients treated with methadone and 69 patients with clozapine) for CYP3A activity using the midazolam phenotyping test and genotyped them for CYP3A4, CYP3A5, and CYP3A7 genetic variants, including the single nucleotide polymorphism (SNP) rs4646437C>T in intron 7 of CYP3A4. Owing to the fact that CYP enzymes require electron transfer through the P450 oxidoreductase (POR), and functional impairment has been shown for the POR*28 SNP, this polymorphism was also analysed. RESULTS: We show that CYP3A4, CYP3A5 and CYP3A7 genotypes, including the SNP rs4646437C>T, do not reflect the inter-individual variability of CYP3A activity (P>0.1). In contrast, POR*28 TT genotype presents a 1.6-fold increase in CYP3A activity compared with POR*28C carriers (n = 182, P = 0.004). This finding was replicated in the second independent dataset (n = 69, P = 0.04). CONCLUSION: The SNP POR*28 seems to be a better genetic marker of the variability of total CYP3A activity in vivo than CYP3A4, CYP3A5 and CYP3A7 genetic variants.
Authors: Walter L Miller; Vishal Agrawal; Duanpen Sandee; Meng Kian Tee; Ningwu Huang; Ji Ha Choi; Kari Morrissey; Kathleen M Giacomini Journal: Mol Cell Endocrinol Date: 2010-11-09 Impact factor: 4.102
Authors: Julia M Barbarino; Christine E Staatz; Raman Venkataramanan; Teri E Klein; Russ B Altman Journal: Pharmacogenet Genomics Date: 2013-10 Impact factor: 2.089
Authors: Pauline Lancia; Tiphaine Adam de Beaumais; Valéry Elie; Florentine Garaix; Marc Fila; François Nobili; Bruno Ranchin; Pascale Testevuide; Tim Ulinski; Wei Zhao; Georges Deschênes; Evelyne Jacqz-Aigrain Journal: Pediatr Nephrol Date: 2018-02-04 Impact factor: 3.714
Authors: Georgia Ragia; Vana Kolovou; Anna Tavridou; Laure Elens; Alexandros D Tselepis; Moses Elisaf; Ron H N Van Schaik; Genovefa Kolovou; Vangelis G Manolopoulos Journal: Mol Diagn Ther Date: 2014-06 Impact factor: 4.074