Presence Of Variant Allele Research Articles

Impact of Matrix Metalloproteinase-8 Polymorphisms on Nasopharyngeal Carcinoma Risk.

Upregulation of matrix metallo-proteinase-8 (MMP-8) serves as a protein-based indicator for predicting nasopharyngeal carcinoma (NPC) metastasis. Nevertheless, the role of MMP-8 genotypes in NPC has never been investigated. This study aimed to explore the involvement of MMP-8 genotypes in NPC development. We employed the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique to analyze MMP-8 genotypes, specifically C-799T (rs11225395), Val436Ala (rs34009635), and Lys460Thr (rs35866072), in a Taiwanese cohort comprising 208 NPC cases and 416 healthy controls. Individuals with either heterozygous or homozygous variant genotypes of MMP-8 rs11225395 showed no significant change in NPC risk compared to those with the wild-type genotype [odds ratio (OR)=0.97 and 0.79, 95% confidence intervals (95%CI)=0.68-1.38 and 0.46-1.36; p=0.9304 and 0.4736, respectively]. Similarly, there was no significant association between the heterozygous genotypes of MMP-8 rs34009635 and NPC risk (OR=0.66, 95%CI=0.24-1.84; p=0.5738). For MMP-8 rs35866072, all individuals in the study were of the TT genotype. Furthermore, the presence of variant alleles at MMP-8 rs11225395 or rs34009635 did not result in altered NPC risk (OR=0.91 and 0.66, 95%CI=0.71-1.16 and 0.24-1.84, p=0.4876 and 0.5769, respectively). Additionally, no significant association was observed between MMP-8 rs11225395 variant genotypes and NPC risk among individuals regardless of smoking, alcohol consumption, or betel quid chewing habits (all p>0.05). There was no association between the MMP-8 genotypes rs11225395, rs34009635, or rs35866072 and NPC risk among Taiwanese individuals. Moreover, no combined effects of MMP-8 genotype with smoking, alcohol consumption, or betel quid chewing habits on NPC risk were observed.

Pharmacogenomics of Fludarabine in Pediatric HCT Recipients: Preliminary Results

Introduction: Total Body Irradiation (TBI) conditioning regimens are considered standard of care for pediatric hematopoietic cell transplant (HCT) recipients. However, TBI has many long-term effects, so avoiding it in young HCT recipients is critical. Fludarabine is frequently used in combination with other chemotherapeutic agents like busulfan and/or thiotepa in non-TBI based conditioning regimens. While multi-drug conditioning aims to avoid TBI-related late-effects, little is known about the effect of variations in genes that metabolize these drugs (pharmacogenomics/PGx) on clinical outcomes including engraftment, relapse, and acute drug-related toxicities. In this study, we investigated the pharmacogenomic effects on HCT outcomes such as event-free outcomes and re-transplantation outcomes, as well as fludarabine's pharmacokinetics (PK).Methods: This ongoing study included pediatric patients from a nationwide multi-center study who received fludarabine in combination with other agents as busulfan and thiotepa. From literature searches and PharmGKB databases, we selected 70 SNPs in 30 candidate pharmacological genes for these drug pathways. SNPs with a minor allele frequency of 10% were further selected for analysis with different endpoints such as: 1) Cumulative incidence with disease relapse with re-transplantation (using Gray's methods, controlling for competing risks); 2) fludarabine PK with cumulative area under the curve (cAUC); 3) 1-month-post-transplant chimerism levels defined as sufficient (CD3 ≥80% and CD14/15 ≥95% chimerism) and insufficient (CD3 <80% and CD14/15 <95% chimerism); and 4) event-free outcomes (comparing patients alive and well vs. others) OR alive re-transplantation outcomes (alive with vs. without re-transplantation). SNPs with an association p-value <0.05 were considered significant using generalized linear models from the SNPassoc R package.Results: Total of 87 patients included in the analysis had a median age of 3.5 (0.2 - 17.9) years, 63% were male, 48% were Caucasian, 85% had received allogenic HCT, and 43% had malignant hematologic disease (Table 1). For SNP rs2277119 in CYP39A1, presence of T allele was associated with greater cumulative incidence of re-transplantation (TC-TT vs. CC genotype: HR=3.64 (95% CI=1.14-11.62), p=0.02, Figure 1A); and SNP rs4715354 in GSTA5, presence of G allele was associated with lower cumulative incidence of re-transplantation (AG-GG vs. AA: HR=0.32 (95% CI=0.11-0.95), p=0.037, Figure 1B). In 79% of patients with available fludarabine cAUC (median of 3.72 mg•hr/L), we evaluated fludarabine pathway gene SNPs for association with cAUC. Within SNPs rs3925058 in CMPK1 and rs11853372 in the uptake transporter SLC28A1, presence of variant allele was associated with higher fludarabine cAUC (rs3925058: GA-AA vs. GG, p=0.049, Figure 2A, and rs11853372 GG-GT vs. TT, p=0.003, Figure 2B); and for a 3'-UTR SNP rs2037067 in TENM3/DCTD, the variant allele was associated with lower fludarabine cAUC levels (CT-CC vs. TT, p=0.005, Figure 2C). In an exploratory analysis with event-free outcomes, patients with variant allele for SNPs rs9937 in RRM1, rs2072671 in CDA, rs324148 in SLC29A1, and rs7533657 in CTPS1 had higher odds of having an event compared to patients with the reference allele; while rs11577910 in CTPS1 had a better outcome with presence of variant allele. With respect to patient's status being alive with re-transplantation outcomes, variants SNPs with rs507964 in SLC29A1, rs4244285 in CYP2C19, rs1021737 in CTH, rs1561876 in STIM1, and rs1130609 in RRM2 have high odds of re-transplantation. At 1-month follow-up, variant SNP rs12144160 in CTPS1 was associated with sufficient chimerism in CD3 and CD14/15.Conclusions: In this study, we have identified a number of SNPs that predict interpatient variability in clinical outcomes and fludarabine levels in pediatric HCT recipients. Results so far showed potential to predict outcomes and develop strategies that will consider pharmacogenomics when determining fludarabine doses in pediatric HCT recipients. Our ongoing study is focused on establishing and validating the pharmacogenetic markers predictive of pharmacokinetics of busulfan, fludarabine and thiotepa and clinical outcomes in pediatric HCT recipients.Acknowledgements: This study was supported by Florida Department of Health - Live Like Bella Discovery Award (9LA04). [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Drug Transporter ABCB1 SNP Predicts Outcome in Patients with Acute Myeloid Leukemia Treated with Gemtuzumab Ozagamicin: A Report from Children's Oncology Group AAML0531 Trial

Background: Gemtuzumab Ozogamicin (GO), is first ever approved immunotherapy for relapsed AML patients. GO is a humanized anti-CD33 antibody linked with the toxin calicheamicin gamma. Calicheamicin induces DNA damage and cell death once the linked CD33 antibody facilitates its uptake. Previous studies have shown that the drug efflux transporter PgP1, which is encoded by gene ABCB1, influences the cellular accumulation of calicheamicin. PgP1 activity in leukemic cells is also inversely correlated with GO response in patients with AML. Although GO was withdrawn from market due to lack of benefit and increase in early mortality observed in SWOG-S0106 study subsequent multiple randomized studies have shown benefit of GO with significant improvement observed in patients with favorable cytogenetic risk features. In light of these results and recent favorable voting by FDA oncology drug advisory committee based on results of ALFA-0701 trail demonstrating a favorable risk:benefit profile for GO there is increased enthusiasm among AML investigators. Given the potential comeback of GO, it is very timely to focus efforts on identifying genetic biomarkers that can improve our ability to develop personalized treatment with GO. In this study evaluate whether single nucleotide polymorphisms (SNPs) in ABCB1 gene are predictive of GO response in patients with AML.Method: Genomic DNA samples from 942 patients enrolled in the COG trial AAML0531 who gave consent for the study were genotyped for 12 SNPs in the ABCB1 gene . Since AAML0531 was designed to test the benefit of GO in a randomized manner, we analyzed the effect of ABCB1 genotypes on outcomes and risk of relapse (RR) between patients treated with or without addition of GO (GO vs. No-GO respectively).Results: The ABCB1 SNP C3435T (rs1045642) was significantly associated with outcome when analyzed by GO vs. No-GO arm. Presence of C3435T change has been previously associated with lower PgP1 expression. For AML patients in the GO arm, presence of variant allele (CT and TT genotype) was significantly associated with lower risk of relapse (RR) from the end of course 1 (GO vs. No-GO arm: RR: 30 ± 6%, n = 259 vs. 46 ± 7%, n= 235; P < 0.0001) and better 5-year event free survival (EFS) from study than for those in the No-GO arm (GO vs. No-GO arm: 55 ± 6%, n = 340 vs. 45 ± 5%, n= 337; P= 0.006). However, patients with the CC genotype showed no differences in RR (GO and No-GO arms: 45 ± 10%, n = 97 vs. 40 ± 11%, n= 91; P= 0.514) and EFS (GO and No-GO arms: 44 ± 9%, n = 128 vs. 50 ± 9%, n= 132; P= 0.425) between the GO and No-GO arms (Fig 1). Further the rs1045642 genotype was significantly associated with EFS (CC vs. CT/TT: 44 ± 9% vs. 55 ± 6%; P=0.022) and RR (CC vs. CT/TT 45 ± 10% vs. 30 ± 6%, P=0.007) for patients in the GO arm but for those in the No-GO arm no difference in outcome between the genotypes was observed (RR: P=0.278; EFS P=0.466).Conclusion: Our results show that for the nonsynonymous SNP rs1045642 (C>T) in an drug efflux transporter ABCB1, the presence of T allele is associated with better response in patients treated with GO based as compared to standard arm. Since ABCB1 is involved in efflux of calicheamicin the presence of a low expression T allele might result in higher intracellular accumulation of calicheamicin and thus better response in patients treated with GO. [Display omitted] DisclosuresLoken:Hematologics Inc: Employment, Equity Ownership. Walter:ADC Therapeutics: Research Funding; Aptevo Therapeutics: Research Funding.

Pharmacogenetic algorithm for predicting daily dose of warfarin in Caucasian patients of Czech origin

Abstract Objectives Warfarin use is limited by a low therapeutic index and significant interindividual variability of the daily dose. The most important factor predicting daily warfarin dose is individual genotype, polymorphisms of genes CYP2C9 (warfarin metabolism) and VKORC1 (sensitivity for warfarin). Algorithms using clinical and genetic variables could predict the daily dose before the initiation of therapy. The aim of this study was to develop and validate an algorithm for the prediction of warfarin daily dose in Czech patients. Methods Detailed clinical data of patients with known and stable warfarin daily dose were collected. All patients were genotyped for polymorphisms in genes CYP2C9 and VKORC1. Results Included patients were divided into derivation (n=175) and validation (n=223) cohorts. The final algorithm includes the following variables: Age, height, weight, treatment with amiodarone and presence of variant alleles of genes CYP2C9 and VKORC1. The adjusted coefficient of determination is 72.4% in the derivation and 62.3% in the validation cohort (p&lt;0.001). Conclusions Our validated algorithm for warfarin daily dose prediction in our Czech cohort had higher precision than other currently published algorithms. Pharmacogenetics of warfarin has the potential in the clinical practice in specialized centers.

Genetic polymorphisms in hMSH2 and hMLH1 genes are associated with prognosis in epithelial ovarian cancer patients

ObjectiveDNA mismatch repair deficiency is not only thought to promote tumorigenesis but is also suggested to be associated with platinum-based chemotherapy treatment. In this study, we investigated the effects of...

ABCB1 rs1045642 C>T Change Is Associated with AML Cell Line Sensitivity to Calicheamicin

Introduction: Gemtuzumab ozogamicin (GO), a CD33-antibody conjugated to DNA damaging cytotoxin-calicheamcin is a re-emerging and promising drug in AML treatment. Promising results from multiple clinical trials demonstrated GO improved outcomes in both adult and pediatric patients with most pronounced effect in favorable-risk cytogenetics. In light of these results GO was reapproved for treatment of AML by FDA in Sep 2017. Given the anticipated increase in GO use post approval, it is very timely to understand mechanisms contributing to differences in patient response. Calicheamicin releases intracellularly and causes DNA strand breaks which leads to apoptosis and cell death. The anti-leukemic effects of GO are thus entirely due to calicheamicin-induced DNA damage. Given that calicheamicin is a substrate of drug transporter ABCB1 (Pgp1), genetic polymorphisms in ABCB1 can impact the intra-cellular accumulation of calicheamicin and thus clinical outcome. Our group have recently shown that ABCB1 synonymous SNP rs1045642 C>T (also well known as 3435C>T) is associated with clinical outcome in children with AML trial, now we report the results of the in vitro evaluation of impact of ABCB1 SNP on calicheamicin mediated cell cytotoxicity.Methods: To understand differences in in vitro calicheamicin toxicity mediated by ABCB1 variation, HL-60 cells with low native ABCB1 expression were transfected with expression plasmid of ABCB1*1 (rs1045642-C and also WT for other two other SNPs in ABCB1) (WT Plasmid), and rs1045642-T. Cells were harvested 48 hours' post-transfection and treated with 40nM calicheamicin for 24 hours. Posttreatment cell were stained with permeant nuclear stain (NucRed® 647 Live Invitrogen) that emits bright far-red fluorescence upon binding to DNA in live cells. One-hour after incubation with the dye, calicheamicin toxicity was assessed by checking cell viability using flow cytometry (BDTM LSR II) and Nikon fluoresce microscope for additional visualization.Results: As shown in Figure 1a, our previous data show rs1045642 a synonymous coding change in ABCB1, in patients treated with GO presence of variant allele (CT/TT) is associated with significantly improved outcome as compared to patients with CC genotype (risk of relapse CC=45±10%, CT=30±7% TT=28±10%, CC vs. CT/TT p=0.007). Consistent with these results we observe significant decrease in cell viability with transfection with ABCB1-rs1045642/3435T as compared to the ABCB1-rs1045642/3435-C (P < 0.05) expression constructs. These results indicate that higher levels of calicheamicin toxicity in ABCB1-3435T transfected cells as opposed to cells transfected with the WT plasmid (Figure 1b and c) probably due to impact of T allele on ABCB1 levels. rs1045642-T allele has been shown to be associated with lower ABCB1 expression in several studies and with higher expression in one study. Hofmeyer et al has previously inked TT genotype of rs1045642 with lower expression and activity of ABCB1 which is consistent with our observation with respect to calicheamicin. Although more work is required to establish the clear relationship between ABCB1 genotypes and calicheamicin efflux, our results suggest that presence of ABCB1- low expressing rs1045642 TT genotype might be resulting in lower-efflux and thus higher intracellular abundance of calicheamicin in leukemic cells which in turn makes cells more sensitive to calicheamicin.Acknowledgments: Funding support from R21CA155524 and Children's Oncology group [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Venous Thrombosis in a Child with Burkitt Lymphoma Receiving Chemotherapy: A Clinical Case

Background. Venous thrombosis is extremely rare in children of early age; however, it occurs as a frequent and serious complication in children with hemoblastosis. The phenomenon is basically caused by the imbalance of blood coagulation system associated with the main disease, prolonged use of the central venous catheter, and polychemotherapy; hereditary predisposition contributes to the development of the complication as well. Clinical Case Description. A 12-year-old patient B. was diagnosed with Burkitt lymphoma. During chemotherapeutic treatment, the thrombosis of right internal jugular vein and right subclavian vein was registered. The thrombosis recurrence was observed at the end of specific therapy. The family history was burdened by cardiovascular and oncological diseases, consequently we performed the molecular-genetic analysis to reveal the presence of allelic variants associated with thrombophilia in the genes F2, F5, F9, F13A1, HABP2, HCF2, HRG, MTHFR, PLAT, PROC, PROS1, SERPINC1, THBD. The F5 gene Leiden mutation (c.1601G&gt;A) in heterozygous state and intronic variant in the PROC gene encoding protein C (c.-21-37G&gt;A) were revealed. The pharmacogenetic testing was conducted to personalize an ticoagulant and antiplatelet therapy.Conclusion. The detection of genetic risk factors for inherited thrombophilia is vital for early diagnostics of thrombotic complications in patients on chemotherapy. Key

Farmacogenómica: la medicina personalizada

The main objective of pharmacogenomics (PGx) is defining an individualized pharmacological treatment based on the genetic profile of each patient. Thus, the classical paradigm of clinical treatment focused on the disease is becoming a new approach, Personalized Medicine. The expression and function of enzymes and proteins involved in the drug pharmacokinetics and pharmacodynamics can be modified by genetic polymorphisms. Thereby, the presence of allelic variants allows predicting the pharmacological response guaranteeing the treatment efficacy and safety.Nowadays, two different approaches have been described for the clinical application of PGx by these variants identification: candidate gene analysis and genome wide association studies. Despite improving the effectiveness, safety and cost-effectiveness of treatments, the PGx clinical implementation has slowed down due to a series of barriers that will be reviewed in this work, as well as their possible solutions.

Pharmacogenetic variants and vitamin K deficiency: a risk factor or trigger for fibrosing interstitial pneumonias?

Fibrosing interstitial pneumonias are associated with various stages of fibrosis. The cause of this group of syndromes remains largely unknown. For most of these diseases, a genetic basis, environmental factors and certain triggers have been suggested as possible risk factors. Various studies have found an association between genetic polymorphisms, or the presence of certain variant alleles, and the occurrence and/or progression of interstitial pneumonias of unknown origin. An acute exacerbation of idiopathic pulmonary fibrosis shows characteristics of diffuse alveolar haemorrhage (DAH). DAH can be aggravated by vitamin K deficiency. This review deals with pharmacogenetic factors underlying interindividual differences of vitamin K status in patients with interstitial pneumonias and the possibilities for a personalized approach to patient management. DAH has been associated with the presence of variant alleles in vitamin K epoxide reductase complex 1, cytochrome P450 (CYP)2C9 and CYP2C19 genes. Vitamin K deficiency has been associated with an increased risk for the development of DAH and progression and/or deterioration of interstitial pneumonias. This is in line with plausible pathophysiological mechanisms. However, clinical use should be confirmed. DAH has been associated with vitamin K deficiency and suggested as potential trigger of fibrosing interstitial pneumonias. Information on genetic variation might benefit ongoing/new clinical trials, design of which should reflect needs to address relevance of testing gene variants. Whether vitamin K supplementation may prevent exacerbations or progression of interstitial pneumonias needs to be explored in future studies.

Unraveling the molecules hidden in the gray shadows of quantitative disease resistance to pathogens

Una de las preguntas más desafiantes del fitomejoramiento y de la fitopatología molecular es ¿cuáles son las bases genéticas y moleculares de la resistencia cuantitativa a enfermedades?. El escaso conocimiento de cómo este tipo de resistencia funciona ha obstaculizado que los fitomejoradores la aprovecharlo plenamente. Para superar estos obstáculos se han desarrollado nuevas metodologías para el estudio de rasgos cuantitativos. Los enfoques como el mapeo genético, la identificación de loci de rasgos cuantitativos (QTL) y el mapeo por asociaciones, incluyendo el enfoque de genes candidatos y los estudios de asociación amplia del genoma, se han llevado a cabo históricamente para describir rasgos cuantitativos y por lo tanto para estudiar QDR. Además, se han proporcionado grandes avances en la obtención de datos fenotípicos cuantitativos para mejorar estos análisis. Recientemente, algunos genes asociados a QDR han sido clonados, lo que conduce a nuevas hipótesis sobre las bases moleculares de este tipo de resistencia. En esta revisión presentamos los avances más recientes sobre QDR y la correspondiente aplicación, que han permitido postular nuevas ideas que pueden ayudar a construir nuevos modelos. Algunas de las hipótesis presentadas aquí como posibles explicaciones para QDR están relacionadas con el nivel de expresión y el splicing alternativo de algunos genes relacionados con la defensa, la acción de "alelos débiles" de genes R, la presencia de variantes alélicas en los genes implicados en la respuesta de defensa y un papel central de quinasas o pseudoqinasas. Con la información recapitulada en esta revisión es posible concluir que la distinción conceptual entre resistencia cualitativa y cuantitativa puede ser cuestionada ya que ambos comparten importantes componentes.

Clinical applications of pharmacogenomics.

Pharmacogenomics is an emergent field aimed at tailoring pharmacological therapy. Genetic polymorphisms can modify the expression and function of enzymes and proteins involved in drug metabolism, affecting absorption, distribution, biotransformation and excretion as well as the drug-target interaction. Therefore, the presence of allelic variants will classify people as poor, extensive or rapid/ultra rapid metabolizers, modifying drug efficacy and safety. In this work, the state of art in relation to this discipline is presented and the genetic variants of enzymes that are involved in drug pharmacokinetics or pharmacodynamics are described. The effects of these variants on the therapeutic response to drugs used in our country are also discussed.

Association of polymorphisms of platelet receptors GPIa (807C>T), GPVI (13254T>C), and P2Y12 (34C>T and H1/H2 haplotype) with increased risk of periprocedural bleeding in patients undergoing coronary angiography/percutaneous coronary intervention.

IntroductionPeriprocedural bleeding related to coronary angiography (CAG) or percutaneous coronary intervention (PCI) is associated with worse prognosis. Determining genetic variations associated with increased bleeding risk may help to identify high-risk patients.AimTo analyse the association between single nucleotide polymorphisms (SNPs) of crucial haemostatic platelet receptors (GPIa, GPVI, P2Y12) and the risk of periprocedural bleeding complications related to CAG/PCI.Material and methodsThe population consisted of 73 patients with ischaemic heart disease who developed bleeding complications within 30 days after CAG/PCI and 331 patients without bleeding. The frequency of SNPs of GPIa 807C/T, GPVI 13254T/C, P2Y12 32C/T, and P2Y12 H1/H2 haplotype was analysed using polymerase chain reaction (PCR) hybridization methods.ResultsThe prevalence of variant alleles GPIa 807T, GPVI 13254C, P2Y12 34T, and P2Y12 H2 haplotype in the total study population was 56.7%, 20.3%, 56.2%, and 24.3%, respectively. The presence of variant alleles was not related to increased risk of periprocedural bleeding: GPIa 807C/T (OR = 1.29, 95% CI: 0.75–2.24, p = 0.334), GPVI 12354T/C (OR = 0.82, 95% CI: 0.40–1.64, p = 0.551), P2Y12 34C/T (OR = 0.71, 95% CI: 0.42–1.22, p = 0.189), P2Y12 H1/H2 haplotype (OR = 0.69, 95% CI: 0.35–1.36, p = 0.258). The frequency of the homozygous form of P2Y12 H2 haplotype was higher in the group of patients who developed bleeding (OR = 2.79, 95% CI: 0.51–13.77, p = 0.161).ConclusionsNo significant association of the SNPs of GPIa 807C/T, GPVI 13254T/C, P2Y12 32C/T, and P2Y12 H1/H2 haplotype with increased risk of periprocedural bleeding was found in patients with ischaemic heart disease undergoing CAG/PCI.

From Six Gene Polymorphisms of the Antioxidant System, Only GPX Pro198Leu and GSTP1 Ile105Val Modulate the Risk of Acute Myeloid Leukemia.

Oxidative stress might contribute to the occurrence of cancers, including the hematological ones. Various genetic polymorphisms were shown to increase the quantity of reactive oxygen species, a phenomenon that is able to induce mutations and thus promote cancers. The purpose of the study was to evaluate the association between CAT C262T, GPX1 Pro198Leu, MnSOD Ala16Val, GSTM1, GSTT1, and GSTP1 Ile105Val gene polymorphisms and acute myeloid leukemia risk, in a case-control study comprising 102 patients and 303 controls. No association was observed between AML and variant genotypes of CAT, MnSOD, GSTM1, and GSTT1 polymorphisms. Our data revealed a statistically significant difference regarding the frequencies of GPX1 Pro198Leu and GSTP1 Ile105Val variant genotypes between AML patients and controls (p < 0.001). Our results showed no association in the distribution of any of the CAT C262T, GPX1 Pro198Leu, GSTM1, GSTT1, and GSTP1 polymorphisms regarding age, gender, FAB subtype, cytogenetic risk groups, FLT3 and DNMT3 gene mutations, and overall survival. Our data suggests that the presence of variant allele and genotype of GPX1 Pro198Leu and GSTP1 Ile105Val gene polymorphisms may modulate the risk of developing AML.

Functional variants in CYP1B1, KRAS and MTHFR genes are associated with shorter telomere length in postmenopausal women

Estrogens and antioxidants indirectly alleviate telomere attrition. However, available clinical data on the association between hormone exposure and telomere length are inconclusive. In the present study, we examined the effects of exogenous estrogen use and of some genetic factors implicated in estrogen metabolism and oxidative stress response on mean leukocyte telomere length. We studied 259 postmenopausal women. Genotyping was conducted for CYP1B1 (rs1056836), COMT (rs4680), GSTP1 (rs1695), MnSOD (rs4880), KRAS (rs61764370), and MTHFR (rs1801133 and rs1801131) polymorphisms. Mean leukocyte telomere length was measured using a quantitative real-time PCR assay. In multivariate analysis we found no association between oral contraceptives or hormone replacement therapy (HRT) and mean leukocyte telomere length. The presence of variant alleles in CYP1B1, KRAS and MTHFR genes was statistically significantly associated with shorter mean leukocyte telomere length. Further, the data provided evidence for the effect modification of the association between HRT and mean leukocyte telomere length by the CYP1B1, KRAS and MTHFR genotypes. Our findings suggest that functionally relevant genetic variants within estrogen and folate metabolic pathways may influence telomere length. We propose these genetic factors should be taken into consideration when interpreting associations between hormone exposure and telomere length.

The MTHFR C677T Polymorphism Is Related to Plasma Concentration of Oxidized Low-Density Lipoprotein in Adolescents with Cardiovascular Risk Factors

Aim: The aim of this study was to investigate possible relationships among the A1298C (rs1801131) and C677T (rs1801133) polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and levels of homocysteine, vitamins B₆, B₁₂, folic acid and lipid profile, including oxidized low-density lipoprotein (ox-LDL), of adolescents at cardiovascular risk. Methods: We recruited 115 adolescents (10-19 years old), 58.3% (n = 67) female, from a public school in Brazil who underwent anthropometric, biochemical and genetic tests as well as food consumption evaluation. Results: An important prevalence of hyperhomocysteinemia (19.1%) and alterations in triacylglycerol (17.4%), total cholesterol (26.9%) and high-density lipoprotein (HDL) cholesterol (48.0%) concentrations were observed, as well as low vitamin B₆ concentrations (23.5%). The categorization of homocysteine concentrations into tertiles revealed significant differences in serum concentrations of folate, vitamin B₁₂ and HDL, waist circumference and intake of total and saturated fat among the tertiles. The presence of variant alleles regarding the MTHFR C677T polymorphism interfered with vitamin B₆ and ox-LDL cholesterol concentrations. There was a trend for higher waist circumference values in T carriers (C677T), but not in C carriers (A1298C). Conclusions: The MTHFR C677T allele was associated with higher plasma vitamin B₆ and ox-LDL compared to the CC genotype.

Genetic Determinants of CYP2C19 Gene *2 and *3 Loss of Function Alleles and Response to Anti Platelet Therapy (Clopidogrel) and Cardiovascular Events. (A Study in Kashmir, North India)

Background: Studies have demonstrated that the mutant *2 and*3 allele of the CYP2C19 loss-of-function polymorphism is associated with diminished metabolization of clopidogrel and an attenuated platelet response to clopidogrel treatment. Since no such study has been conducted in this region, we examined CYP2C19 polymorphism in Acute Coronary Syndrome (ACS) patients on clopidogrel treatment, and its effect on the cardiovascular outcomes. Material and Methods: A total of 100 samples of ACS were included in this study and genotyping of CYP2C19 *2 and *3 gene polymorphisms was performed by a Polymerase chain reaction-Restriction fragment length polymorphism (PCR-RFLP). Results: The distribution of CYP2C19*2 allele wild *1/*1, Heterozygous *1/*2 and homozygous mutant *2/*2 genotypes was 56%, 34% and 10% respectively while for CYP2C19*3 wild*1/*1 and heterozygous *1/*3 genotypes was 84% and 16% respectively. The frequency of compound heterozygotes (*2/*3) was found in 9% (9 of 100 patients). CYP2C19 *1/*2 allele was found in 03 of 34 (8.8%) patients who had CV events followed by 2 of 10 (20%) patients with mutant genotype CYP2C19*2 (*2/*2) on follow up. In the CYP2C19*3, 31.2% having heterozygous genotype (*1/*3) had CV events as compared to 11.9% with *1/*1 (31% v/s 11.9% p> 0 .05). In the poor-metabolizer group (*2/*2 or *2/*3), 20.1% of patients had CV events on follow up compared to 15.6% in the extensive metabolizer group (*1/*1), whereas in the intermediate group only 10% of patients had CV events (p>0.05). Conclusion: We conclude that patients carrying CYP2C19 loss-of-function alleles had a higher rate of subsequent cardiovascular events than as against those with normal allele. Lack of significant events even in presence of variant alleles justifies us to some extent to continue clopidogrel in our patients

Abstract LB-295: The roles of genetic polymorphisms for susceptibility of colorectal cancer in Chinese Lynch syndrome families

Abstract Background: Lynch syndrome is associated with germ-line mutations in DNA mismatch repair (MMR) genes. Polymorphisms in candidate genes that have been implicated in sporadic colorectal cancer (CRC) risk may also play roles in hereditary CRC risk. In this retrospective analysis, we examined multiple polymorphisms (including MSH2 IVS10+12A&amp;gt;G, MLH1 A-93G, NAT1, GSTM1, GSTP1 Iel105Val, GSTA1 C-69T, TP53 Arg72Pro, CYP17A1 T-34C, CYP1A1*2C, CYP1A1*1F, TGFBR1 IVS7+24G&amp;gt;A, and TGFBR2 G-875A) to assess the genetic effect on the CRC risk in MLH1 and MSH2 mutation carriers. Material and Methods: DNA samples from 284 mutation-positive Lynch syndrome participants were genotyped by Sequenom iPLEX MassArray. Univariate and multivariate analysis was used to analyze the association between the genetic polymorphisms and CRC risk. Results: We found significant associations between the presence of variant alleles in TP53 Arg72Pro (G&amp;gt;C) and TGFBR2 G-875A genes and the risk of developing CRC among MLH1 and MSH2 mutation carriers. The TP53 Arg72Pro GC+CC genotypes were associated with decreased risk of CRC (hazard ratio (HR) = 0.63, 95% confidence interval (CI) = 0.42-0.94). However, the TGFBR2 G-875A GA+AA genotypes were associated with increased risk of CRC (HR = 1.60, 95% CI = 1.06-2.42). None of the other gene polymorphisms examined were associated with CRC risk. Conclusion: To our best knowledge, our study is the first and largest study investigating multiple genetic modifiers that may influence CRC risk in Chinese Lynch syndrome families. Our results suggested that TP53 and TGFBR2 polymorphisms may associate with CRC risk among MLH1 and MSH2 mutation carriers. Such knowledge may be helpful in identifying high-risk individuals who require more intensive surveillance. Citation Format: Chih-Ching Yeh, Reiping Tang, Huei-Tzu Chien, Chih-Hsiung Lai, Li-Ling Chiu, Tsai-Ping Lo, Kuan-Yi Hung, Chun-Yi Wang, Jeng-Fu You, Chao A. Hsiung, Ling-Ling Hsieh. The roles of genetic polymorphisms for susceptibility of colorectal cancer in Chinese Lynch syndrome families. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-295. doi:10.1158/1538-7445.AM2014-LB-295

Prnp gene and cerebellum volume in patients with refractory mesial temporal lobe epilepsy

The cellular prion protein, encoded by Prnp gene, is involved in neuroprotection, neuroplasticity and neurodevelopment. The variant allele Valine at codon 129 of the Prnp was associated with decreased brain volume in healthy volunteers and schizophrenic patients. We investigate the association between the cerebellum volume and the presence of variant allele Valine at codon 129 of the Prnp gene in patients with mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS). The Prnp coding sequence was determined in 41 refractory MTLE-HS patients. The cerebellum volume corrected by the intracranial volume of patients with the normal Prnp genotypes was compared with that of patients presenting the variant alleles at codon 129. Twenty patients showed the Met129Met genotype, 16 showed Met129Val, and 5 had Val129Val. There were no association among clinical, demographic, electrophysiological, antiepileptic drugs used, and the presence of the Prnp variant alleles. The presence of Prnp variant allele at codon 129 was not associated with the analyzed cerebellum volume. Prnp variant alleles at codon 129 are not associated with cerebellum volume in patients with refractory MTLE-HS.

Moderator effect of CYP2B6 genotype in HIV‐1 patients with tuberculosis treated with rifampicin and efavirenz

Efavirenz (EFV) is the preferred non‐nucleoside reverse transcriptase inhibitor component of the ARV regimen in HIV‐TB patients. Concomitant use of EFV with rifampicin (RIF), an important component of first‐line tuberculosis treatment, induces various hepatic cytochrome P450 enzymes and is known to decrease EFV plasma concentrations in healthy volunteers and HIV‐1 patients and EFV plasma concentrations below 1,000 µg/mL have been associated with an increased risk of virological failure [1]. Moreover, previous studies have shown that inter‐individual variability in EFV plasma concentrations are associated with the presence of allelic variants in CYP2B6 gene. Carriers of the T allele of polymorphism 516 G&gt;T are reported to be associated with slower EFV oral clearance. The aim of our study was to determine the influence of CYP2B6 genotype in EFV levels in HIV patients with TB treated with RIF. Four HIV patients who started ARV treatment concomitantly with TB treatment were analyzed. These patients started a regimen based on EFV at doses higher than standard due to RIF interaction. Viral load, CD4+ cell count and plasma levels of EFV in plasma were measured at each visit, and genotyping for CYP2B6 (516G&gt;T) polymorphism were performed. The self‐reported rates of adherence to HAART were very high. One patient, who had TT genotype, required progressive dose reduction by toxic levels (Cmin: 20 µg/mL) and effects on the central nervous system. Dose was adjusted to 600 mg qd despite treatment with RIF, and he required even lower doses after completion of TB treatment, 400 mg qd. Two other patients with non‐mutated genotype (GG) required dose escalation up to 1000 mg qd to achieve minimum recommended EFV concentrations between 1 and 4 µg/mL. All of them achieved virological suppression at six months. The fourth patient, who had non‐mutated genotype, required dose increases for several months until dose adjustment. He needed 1600 mg qd during treatment with RIF. He presented virological failure, likely to maintain infratherapeutic levels of EFV for several months. Our study shows that the variability in EFV pharmacokinetic behaviour justifies the use of therapeutic drug monitoring (TDM) in situations in which there are potential interactions with other drug. Also, it is recommended to know CYP2B6 genotype in patients receiving HIV‐TB to predict their metabolizing behaviour. TDM in clinical practise continues to be the best tool for optimizing the dosing of EFV.

Development of Cocaine-Induced Interstitial Lung Damage in Two CYP2C and VKORC1 Variant Allele Carriers

Often, the connection between drug use and the development of related inflammatory damage or idiosyncratic toxicities is hard to recognize and objectify. The presence of cytochrome P450 (CYP) variant genotypes appears to be a substantial susceptibility risk factor in the development of drug-induced pulmonary adverse events. We hypothesized that the presence of variant alleles may be associated with serious complications of illicit drug use. We report the cases of two cocaine users who developed a 'flu-like' syndrome with diffuse interstitial infiltrates after cocaine abuse. Genotyping for CYP (CYP2C9, CYP2C19) and vitamin K epoxide reductase complex 1 (VKORC1) allelic variants (-1639G/A and 1173C/T) was performed in these two patients. Both cases were heterozygous for VKORC1 variant alleles, and both possessed a CYP2C polymorphism (case 1: CYP2C19*1/*2; case 2: CYP2C9*1/*3). The described drug abuse cases suggest that an association between the presence of CYP2C and VKORC1 allelic variants and cocaine-induced interstitial lung damage is highly likely. It is assumed that these polymorphisms contribute to intra-individual variability in drug response and toxicity, including cocaine response and toxicity. Moreover, the importance of including pharmacogenomics in the work-up of patients with suspected drug-induced (lung) toxicity, such as alveolar hemorrhage, is highlighted by these cases.