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This multicenter clinical study was aimed at conducting a targeted pharmacogenomic association analysis of residual on‐clopidogrel platelet reactivity in 474 Caribbean Hispanic patients. Platelet reactivity was measured using the VerifyNow P2Y12 assay and clopidogrel resistance was defined as P2Y12 reaction units (PRUs) greater than or equal to 208. Genotyping was performed using the whole‐genome Infinium MEGA BeadChip array. An ancestry‐adjusted, weighted polygenic risk score (wPGxRS) was developed to account for the effect of multiple variants on PRU and compared between clopidogrel responders and nonresponders. The mean PRU across the study cohort was 173.8 ± 68.5 and 33.5% of patients were defined as clopidogrel resistant. Multivariate linear regression showed that 19% of PRU variability was attributed to nine independent predictors, with CYP2C19*2 (rs4244285) accounting for ~ 7% of observed PRU variation (p

Aim: Perform in silico predictions of functional consequences of CYP2C9 variants identified by next-generation sequencing in Puerto Ricans. Methods: Identified low-frequency CYP2C9 variants (minor allele frequencies

Warfarin is the most commonly used oral anticoagulant in sub-Saharan Africa. Dosing is challenging due to a narrow therapeutic index and high interindividual variability in dose requirements. To evaluate the genetic factors affecting warfarin dosing in black-Africans, we performed a meta-analysis of 48 studies (2,336 patients). Significant predictors for CYP2C9 and stable dose included rs1799853 (CYP2C9*2), rs1057910 (CYP2C9*3), rs28371686 (CYP2C9*5), rs9332131 (CYP2C9*6), and rs28371685 (CYP2C9*11) reducing dose by 6.8, 12.5, 13.4, 8.1, and 5.3 mg/week, respectively. VKORC1 variants rs9923231 (-1639G>A), rs9934438 (1173C>T), rs2359612 (2255C>T), rs8050894 (1542G>C), and rs2884737 (497T>G) decreased dose by 18.1, 21.6, 17.3, 11.7, and 19.6 mg/week, respectively, whereas rs7294 (3730G>A) increased dose by 6.9 mg/week. Finally, rs12777823 (CYP2C gene cluster) was associated with a dose reduction of 12.7 mg/week. Few studies were conducted in Africa, and patient numbers were small, highlighting the need for further work in black-Africans to evaluate genetic factors determining warfarin response.

Dagmar F Hernandez-Suarez,1 Mariana R Botton,2 Stuart A Scott,2 Matthew I Tomey,3 Mario J Garcia,4 Jose Wiley,4 Pedro A Villablanca,5 Kyle Melin,6 Angel Lopez-Candales,7 Jessicca Y Renta,8 Jorge Duconge9 1Cardiovascular Medicine Division, Department of Medicine, University of Puerto Rico School of Medicine, San Juan, PR, USA; 2Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA; 3Cardiovascular Medicine Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA; 4Division of Cardiovascular Diseases, Department of Medicine, Montefiore Medical Center/Albert Einstein College of Medicine New York, NY, USA; 5Division of Cardiology, Department of Medicine, New York University Langone Medical Center, New York, NY, USA; 6Department of Pharmacy Practice, University of Puerto Rico Medical Sciences Campus, San Juan, PR, USA; 7Cardiovascular Medicine Division, Department of Medicine, University of Puerto Rico School of Medicine, San Juan, PR, USA; 8Department of Biochemistry, University of Puerto Rico Medical Sciences Campus, San Juan, PR, USA; 9Pharmaceutical Sciences Department, University of Puerto Rico Medical Sciences Campus, San Juan, PR, USA Introduction: High on-treatment platelet reactivity (HTPR) to clopidogrel imparts an increased risk for ischemic events in adults with coronary artery disease. Platelet reactivity varies with ethnicity and is influenced by both clinical and genetic variables; however, no clopidogrel pharmacogenetic studies with Puerto Rican patients have been reported. Therefore, we sought to identify clinical and genetic determinants of on-treatment platelet reactivity in a cohort of Puerto Rican patients with cardiovascular disease. Methods: We performed a retrospective study of 111 patients on 75 mg/day maintenance dose of clopidogrel. Patients were allocated into 2 groups: Group I, without HTPR; and Group II, with HTPR. Platelet function was measured ex vivo using the VerifyNow® P2Y12 assay and HTPR was defined as P2Y12 reaction units (PRU) ≥230. Genotyping testing was performed using Taqman® Genotyping Assays. Results: The mean PRU across the cohort was 203±61 PRU (range 8–324), and 42 (38%) patients had HTPR. Multiple logistic regression showed that 27% of the total variation in PRU was explained by a history of diabetes mellitus, hematocrit, CYP2C19*2, and PON1 p.Q192R. Body mass index (odds ratio [OR]=1.15; 95% CI: 1.03–1.27), diabetes mellitus (OR=3.46; 95% CI: 1.05–11.43), hematocrit (OR=0.75; 95% CI: 0.65–0.87), and CYP2C19*2 (OR=4.44; 95% CI: 1.21–16.20) were the only independent predictors of HTPR. Conclusion: Moreover, we propose a predictive model to determine PRU values as measured by VerifyNow P2Y12 assay for the Puerto Rican Hispanic population. This model has the potential to identify Hispanic patients at higher risk for adverse events on clopidogrel. Keywords: clopidogrel, platelet reactivity, genotyping, Hispanics, Puerto Rico

Background: Variations in several clopidogrel-pharmacogenes have been linked to clopidogrel response variability and clinical outcomes. We aimed to determine the frequency distribution of major polymorphisms on CYP2C19, PON1, ABCB1 and P2RY12 pharmacogenes in Puerto Ricans. Methods: This was a cross-sectional, population-based study of 200 unrelated &ldquo, Guthrie&rdquo, cards specimens from newborns registered in the Puerto Rican newborn screening program (PRNSP) between 2004 and 2014. Taqman&reg, SNP assay techniques were used for genotyping. Results: Minor allele frequencies (MAF) were 46% for PON1 (rs662), 41% for ABCB1 (rs1045642), 14% for CYP2C19*17, 13% for CYP2C19*2, 12% for P2RY12-H2 and 0.3% for CYP2C19*4. No carriers of the CYP2C19*3 variants were detected. All alleles and genotype proportions were found to be in Hardy&ndash, Weinberg equilibrium (HWE). Overall, there were no significant differences between MAFs of these variants in Puerto Ricans and the general population (n = 453) of the 1000 Genome project, except when comparisons to each individual parental group were performed (i.e., Africans, Europeans and East-Asians, p &lt, 0.05). As expected, the prevalence of these markers in Puerto Ricans most resembled those in the 181 subjects from reference populations of the Americas. Conclusions: These prevalence data provide a necessary groundwork for future clinical studies of clopidogrel pharmacogenetics in Caribbean Hispanics.

Aim This study is aimed at developing a novel admixture-adjusted pharmacogenomic approach to individually refine warfarin dosing in Caribbean Hispanic patients. Patients & Methods A multiple linear regression analysis of effective warfarin doses versus relevant genotypes, admixture, clinical and demographic factors was performed in 255 patients and further validated externally in another cohort of 55 individuals. Results The admixture-adjusted, genotype-guided warfarin dosing refinement algorithm developed in Caribbean Hispanics showed better predictability (R2 = 0.70, MAE = 0.72mg/day) than a clinical algorithm that excluded genotypes and admixture (R2 = 0.60, MAE = 0.99mg/day), and outperformed two prior pharmacogenetic algorithms in predicting effective dose in this population. For patients at the highest risk of adverse events, 45.5% of the dose predictions using the developed pharmacogenetic model resulted in ideal dose as compared with only 29% when using the clinical non-genetic algorithm (p

Puerto Ricans are a unique Hispanic population with European, Native American (Taino), and higher West African ancestral contributions than other non-Caribbean Hispanics. In admixed populations, such as Puerto Ricans, genetic variants can be found at different frequencies when compared to parental populations and uniquely combined and distributed. Therefore, in this review, we aimed to collect data from studies conducted in healthy Puerto Ricans and to report the frequencies of genetic polymorphisms with major relevance in drug response. Filtering for healthy volunteers or individuals, we performed a search of pharmacogenetic studies in academic literature databases without limiting the period of the results. The search was limited to Puerto Ricans living in the island, excluding those studies performed in mainland (United States). We found that the genetic markers impacting pharmacological therapy in the areas of cardiovascular, oncology, and neurology are the most frequently investigated. Coincidently, the top causes of mortality in the island are cardiovascular diseases, cancer, diabetes, Alzheimer’s disease, and stroke. In addition, polymorphisms in genes that encode for members of the CYP450 family (CYP2C9, CYP2C19, and CYP2D6) are also available due to their relevance in the metabolism of drugs. The complex genetic background of Puerto Ricans is responsible for the divergence in the reported allele frequencies when compared to parental populations (Africans, East Asians, and Europeans). The importance of reporting the findings of pharmacogenetic studies conducted in Puerto Ricans is to identify genetic variants with potential utility among this genetically complex population and eventually move forward the adoption of personalized medicine in the island.

OBJECTIVES/SPECIFIC AIMS: High on-treatment platelet reactivity (HTPR) with clopidogrel imparts an increased risk for ischemic events in adults with coronary artery disease. Although more potent antiplatelet agents are available, clopidogrel remains the most commonly used P2Y12 inhibitor in Puerto Rico. Platelet reactivity varies with ethnicity and is influenced by both clinical and genetic variables; however, no clopidogrel pharmacogenetic studies with Puerto Rican patients have been reported. Therefore, we sought to identify clinical and genetic determinants of on-treatment platelet reactivity in a cohort of Puerto Rican patients with cardiovascular disease. METHODS/STUDY POPULATION: We performed a retrospective study of 111 Puerto Rican patients on 75 mg/day maintenance dose of clopidogrel. Patients were allocated into 2 groups: Group I, without HTPR; and Group II, with HTPR. Clinical data was obtained from the medical record. Platelet function was measured ex vivo using the VerifyNow® P2Y12 assay and HTPR was defined as P2Y12 reaction units (PRU)≥230. Genotyping of CYP2C19, ABCB1, PON1, PY2R12, B4GALT2, CES1, and PEAR1 was performed using Taqman® Genotyping Assays. RESULTS/ANTICIPATED RESULTS: The mean PRU across the cohort was 203±61 PRU (range, 8–324), and 42 (38%) patients had HTPR. One in four individuals carried at least 1 copy of the CYP2C19*2 variant allele. Hematocrit and PON1 p.Q192R variant were inversely correlated with platelet reactivity (p

Objective: This cross-sectional study was aimed at determining the allele frequencies for the CYP2C19*2, CYP2C19*3, CYP2D6*10 and PON1 (rs662) polymorphisms in the Puerto Rican population. The CYP2C19, CYP2D6 and PON1 genes are known to be associated with functional changes in drug metabolism and activation. Individuals carrying the aforementioned polymorphisms are at a higher risk of suffering from drug-induced adverse events and/ or unresponsiveness from a variety of drugs that includes antidepressants, atypical antipsychotics and antiplatelet compounds. Information on the frequency of these polymorphisms is more commonly found on homogeneous populations, but is scarce in highly heterogeneous populations like Hispanics, as in the case of Puerto Ricans. Method: Genotyping was carried out in 100 genomic DNA samples from dried blood spots supplied by the Puerto Rican Newborn Screening program using Taqman® Genotyping Assays. Results: The Minor Allele Frequencies (MAF) obtained were 9% for CYP2C19*2 and CYP2D6*10, 50% for PON1 (rs662), while the CYP2C19*3 variant was not detected in our study. Furthermore, Hardy Weinberg equilibrium analysis was assessed as well as a comparison between Puerto Rico and other reference populations using a Z-test for proportions. Conclusion: The observed allele and genotype frequencies on these relevant pharmacogenes in Puerto Ricans were more closely related to those early reported in two other reference populations of Americans (Mexicans and Colombians).

Hemoglobin Pôrto Alegre (PA) is a rare hemoglobin resulting from a mutation in β9(A6)Ser → Cys. We describe an asymptomatic Puerto Rican female with combined heterozygosity for Hb PA and Hb S. Since birth, she has maintained normal hemoglobin, bilirubin, LDH levels, and reticulocyte count. Peripheral smear evaluation has revealed normal erythrocyte morphology with no changes suggestive of hemolysis. We conclude that the presence of Hb PA does not increase the risk of red blood cell sickling in patients who carry the Hb S mutation.

Folic acid supplementation can reduce the incidence of neural tube defects. The first reported genetic risk factor for neural tube defects is a C677T mutation in the 5,10-methylenetetrahydrofolate reductase gene, resulting in decreased activity of the enzyme. We examined the enzyme mutation role of methylenetetrahydrofolate reductase in the etiology of neural tube defects in our population. The study group consisted of 204 Puerto Rican individuals including 37 pregnant females with a prenatal diagnosis of neural tube defects in their fetuses, 31 newborns, 36 fathers, and 100 healthy adults. The prevalence of the C677T mutation was examined. Homozygosity for the alanine to valine substitution (TT) was observed in 9% of the controls and 19% of the mothers with children with neural tube defects. Our results indicate that the presence of the T allele at the methylenetetrahydrofolate reductase 677 position may increase the risk of giving birth to an infant with a neural tube defect. (J Child Neurol 2002;17:30-32).

PURPOSE Hemoglobin Hotel Dieu (HbHD) is a high-oxygen affinity variant of HbA never before reported in a Hispanic patient. This Hb variant was first reported in 1981 by Blouquit et al. in a white person with erythrocytosis with a substitution in the beta 99 aspartic acid residue by glycine. METHODS A 13-year-old Puerto Rican boy had pain in his chest, headaches, easy fatigability, and high Hb (as high as 19.1 g/dl). Protein analysis was performed by cellulose acetate, citrate agar, and isoelectric focusing electrophoresis and high-pressure liquid chromatography (HPLC), polymerase chain reaction (PCR) amplification, and DNA sequencing of the second exon of the beta gene in samples obtained from the mother, father, and the patient, and DNA fingerprinting to determine paternity. RESULTS The variant found in the patient migrated on cellulose acetate electrophoresis to a cathodic position relative to HbF, and a band cathodal to HbA and close to HbF on isoelectric focusing electrophoresis. The patient showed an abnormal well-resolved peak on HPLC with a retention time slightly shorter than that for HbS. DNA analysis by direct sequencing of the PCR product demonstrated heterozygosity for codon 99 (GAT-->GGT) in the patient but not in either parent. DNA fingerprinting by multiplex PCR amplification of three simple tandem repeat loci showed that the patient shared alleles in all three loci with both parents, ruling out nonpaternity. CONCLUSIONS The protein and DNA analysis indicate that the erythrocytosis is caused by the presence of HbHD in this Hispanic adolescent.

Neural Tube Defects in Puerto Rico: Correlation between Genetic and Folate Axis (Preliminary Results)

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of folate to methionine Fourteen severe mutations of the MTHFR gene have been found to result in only a 0-20 percent activity of the control MTHFR protein (Goyette, 1995). A common mutation (C677T), which results in high homocysteine and low plasma folate levels, has been associated with a thermolabile form of the MTHFR enzyme, therefore being a risk factor for cardiovascular diseases and neural tube defects (NTD) in the homozygous form (Frosst, 1995). Another mutation in the human MTHFR gene (A1298C) has been found to destroy an MboII recognition site and results in decreased MTHFR activity. Plasma and homocysteine levels are not altered with the A1298C mutation, however this mutation seems to be a risk factor when combined with the C677T mutation (Van der Put NM, 1998). In a prevalence study of the common C677T mutation screening in healthy women and newborn samples was performed we found that 8.6% of the individuals where homozygous for the mutation. These results compare with those found for Ohio Caucasian and Dublin populations (McAndrew, Kirke; 1996). Thirty NTD affected and control families were also analyzed in our laboratory for the C677T and A1298C mutations. Analysis of the A1298C mutation in 51 and 62 individuals from the control and NTD affected families, respectively, resulted in 8 control and 0 NTD affected individuals homozygous for the mutation. Taken together, the results of this study indicates that the Puerto Rican population has a low frecuency of the C677T mutation and confirms that homozygocity for the A1298C mutation does not present a direct risk for NTD. Supported by an RCMI Clinical Research Infrastructure Initiative (RCRII) Award IP20RR11126, National Center for Research Resources, RCMI Human Molecular Genetics Unit, NCRR-NIH RCMI Grant G12RR03051, and the Hereditary Disease Program, Department of Pediatrics, UPR, School of Medicine.