rs7439366, also known as Y268H, is a SNP in the UGT2B7 gene encoding the 2B7 UDP-Glucuronosyltransferase, active primarily in the liver. The rs7439366(C) allele encodes a histidine (H) at amino acid 268, and the (T) allele encodes a tyrosine (Y). Most publications refer to the histidine as the wild-type (more common) allele.
[PMID 17664247] In a study of glucuronidation activity of human livers, rs7439366(T;T) individuals had 28% lower activity than rs7439366(C;C) individuals with respect to O-glucuronidation of tamoxifen metabolites 4-OH-tamoxifen and endoxifen. The authors suggest this may help explain interindividual variability (beyond CYP2D6 variation) in tamoxifen metabolism - and therefore the effectiveness of tamoxifen in reducing breast cancer recurrence.
[PMID 18547414] Genotyping panel for assessing response to cancer chemotherapy.
[PMID 18622261] Single nucleotide polymorphism discovery and functional assessment of variation in the UDP-glucuronosyltransferase 2B7 gene.
[PMID 19779319] CYP2B6, CYP2A6 and UGT2B7 genetic polymorphisms are predictors of efavirenz mid-dose concentration in HIV-infected patients.
[PMID 20973683] Pharmacogenetic impact of UDP-glucuronosyltransferase metabolic pathway and multidrug resistance-associated protein 2 transport pathway on mycophenolic acid in thoracic transplant recipients: an exploratory study.
[PMID 23726609] Uridine Diphosphate Glucuronosyltransferase 2B7 Variant p.His268Tyr as a Predictor of Kidney Allograft Early Acute Rejection
[PMID 24080498] Pharmacogenetic associations with plasma efavirenz concentrations and clinical correlates in a retrospective cohort of Ghanaian HIV-infected patients
[PMID 23130019] Frequencies of 23 functionally significant variant alleles related with metabolism of antineoplastic drugs in the chilean population: comparison with caucasian and asian populations.