Cáncer colorrectal. Variantes génicas en la vía de señalización BMP y ancestría en población mexicana / Colorectal cancer. Genetic variants in BMP signaling pathway and ancestry in the Mexican population

Resumen Introducción: Variantes génicas relacionadas con la vía de señalización de las proteínas morfogenéticas óseas (BMP2, BMP4, GREM1, SMAD7) se han asociado a cáncer colorrectal, principalmente en poblaciones caucásicas. Objetivo: Describir la asociación de variantes en miembros de la vía BMP en población mexicana, caracterizada por su ancestría indoamericana y caucásica. Métodos: Se realizó el genotipado de 1000 casos de cáncer colorrectal y 1043 individuos de control reclutados en la Ciudad de México, Monterrey y Torreón mediante la plataforma Sequenom. Con análisis univariados y multivariados se estudiaron las asociaciones entre cáncer colorrectal y variantes. Resultados: Las variantes rs4444235, rs12953717 y rs4939827 replicaron la asociación con la neoplasia (p ≤ 0.05). La ascendencia caucásica mostró asociación con el tumor. Conclusiones: El estudio mostró las asociaciones entre cáncer colorrectal y las variantes SMAD7 y BMP4, así como con el componente caucásico de la mezcla étnica.

Abstract Introduction: Genetic variants related to bone morphogenetic proteins (BMP2, BMP4, GREM1, SMAD7) signaling pathway have been associated with colorectal cancer, mainly in Caucasian populations. Objective: To describe the association of variants in members of the BMP signaling pathway in a Mexican population, characterized by its indigenous American and Caucasian ancestry. Methods: Genotyping of 1,000 colorectal cancer cases and 1,043 control individuals recruited in Mexico City, Monterrey, and Torreón was carried out using the Sequenom platform. Associations between colorectal cancer and variants were studied with univariate and multivariate analyses. Results: Variants rs4444235, rs12953717 and rs4939827 replicated the association with the neoplasm (p ≤ 0.05). Caucasian ancestry showed association with the tumor. Conclusions: The study replicated the associations between colorectal cancer and SMAD7 and BMP4 variants, with an association being observed with the Caucasian component of the ethnic mix.

Association of variants in MYH7, MYBPC3 and TNNT2 with sudden cardiac death-related risk factors in Brazilian patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is characterized by unexplained left ventricular hypertrophy (LVH) and is one of the major causes of sudden cardiac death (SCD). An exon-targeted gene sequencing strategy was used to investigate the association of functional variants in sarcomeric genes (MYBPC3, MYH7 and TNNT2) with severe LVH and other SCD-related risk factors in Brazilian HCM patients. Clinical data of 55 HCM patients attending a Cardiology Hospital (Sao Paulo city, Brazil) were recorded. Severe LVH, aborted SCD, family history of SCD, syncope, non-sustained ventricular tachycardia and abnormal blood pressure in response to exercise were evaluated as SCD risk factors. Blood samples were obtained for genomic DNA extraction and the exons and untranslated regions of the MYH7, MYBPC3 and TNNT2 were sequenced using Nextera® and MiSEq® reagents. Variants were identified and annotated using in silico tools, and further classified as pathogenic or benign according to the American College of Medical Genetics and Genomics guidelines. Variants with functional effects were identified in MYBPC3 (n = 9), MYH7 (n = 6) and TNNT2 (n = 4). The benign variants MYBPC3 p.Val158Met and TNNT2 p.Lys263Arg were associated with severe LVH (p < 0.05), and the MYH7 p.Val320Met (pathogenic) was associated with family history of SCD (p = 0.037). Increased risk for severe LVH was found in carriers of MYBPC3 Met158 (c.472 A allele, OR = 13.5, 95% CI = 1.80-101.12, p = 0.011) or combined variants (MYBPC3, MYH7 and TNNT2: OR = 12.39, 95% CI = 2.14-60.39, p = 0.004). Carriers of TNNT2 p.Lys263Arg and combined variants had higher values of septum thickness than non-carriers (p < 0.05). Molecular modeling analysis showed that MYBPC3 158Met reduces the interaction of cardiac myosin-binding protein C (cMyBP-C) RASK domain (amino acids Arg215-Ala216-Ser217-Lys218) with tropomyosin. In conclusion, the variants MYBPC3 p.Val158Met, TNNT2 p.Lys263Arg and MYH7 p.Val320Met individually or combined contribute to the risk of sudden cardiac death and other outcomes of hypertrophic cardiomyopathy.

Association of BDNF, HTR2A, TPH1, SLC6A4, and COMT polymorphisms with tDCS and escitalopram efficacy: ancillary analysis of a double-blind, placebo-controlled trial

Objective: We investigated whether single nucleotide polymorphisms (SNPs) associated with neuroplasticity and activity of monoamine neurotransmitters, such as the brain-derived neurotrophic factor (BDNF, rs6265), the serotonin transporter (SLC6A4, rs25531), the tryptophan hydroxylase 1 (TPH1, rs1800532), the 5-hydroxytryptamine receptor 2A (HTR2A, rs6311, rs6313, rs7997012), and the catechol-O-methyltransferase (COMT, rs4680) genes, are associated with efficacy of transcranial direct current stimulation (tDCS) in major depression. Methods: Data from the Escitalopram vs. Electrical Current Therapy for Treating Depression Clinical Study (ELECT-TDCS) were used. Participants were antidepressant-free at baseline and presented with an acute, moderate-to-severe unipolar depressive episode. They were randomized to receive escitalopram/tDCS-sham (n=75), tDCS/placebo-pill (n=75), or placebo-pill/sham-tDCS (n=45). General linear models assessed the interaction between treatment group and allele-wise carriers. Additional analyses were performed for each group and each genotype separately. Results: Pairwise group comparisons (tDCS vs. placebo, tDCS vs. escitalopram, and escitalopram vs. placebo) did not identify alleles associated with depression improvement. In addition, exploratory analyses also did not identify any SNP unequivocally associated with improvement of depression in any treatment group. Conclusion: Larger, combined datasets are necessary to identify candidate genes for tDCS response.

Genetic susceptibility in pharmacodynamic and pharmacokinetic pathways underlying drug induced arrhythmia and sudden unexplained deaths

Abstract Drug-induced arrhythmia is an adverse drug reaction that can be potentially fatal since it is mostly related to drug-induced QT prolongation, a known risk factor for Torsade de Pointes and sudden cardiac death (SCD). Several risk factors have been described in association to these drug-induced events, such as preexistent cardiac disease and genetic variation. Our objective was to study the genetic susceptibility in pharmacodynamic and pharmacokinetic pathways underlying suspected drug-induced arrhythmias and sudden unexplained deaths in 32 patients. The genetic component in the pharmacodynamic pathway was studied by analyzing 96 genes associated with higher risk of SCD through massive parallel sequencing. Pharmacokinetic mediated genetic susceptibility was investigated by studying the genes encoding cytochrome P450 enzymes using medium-throughput genotyping. Pharmacodynamic analysis showed three probably pathogenic variants and 45 variants of uncertain significance in 28 patients, several of them previously described in relation to mild or late onset cardiomyopathies. These results suggest that genetic variants in cardiomyopathy genes, in addition to those related with channelopathies, could be relevant to drug-induced cardiotoxicity and contribute to the arrhythmogenic phenotype. Pharmacokinetic analysis showed three patients that could have an altered metabolism of the drugs they received involving CYP2C19 and/or CYP2D6, probably contributing to the arrhythmogenic phenotype. The study of genetic variants in both pharmacodynamic and pharmacokinetic pathways may be a useful strategy to understand the multifactorial mechanism of drug-induced events in both clinical practice and forensic field. However, it is necessary to comprehensively study and evaluate the contribution of the genetic susceptibility to drug-induced cardiotoxicity. (AU)

Estudio de la relación de la ancestría genética con el riesgo al cáncer colorrectal en Colombia / Study of the relationship between genetic ancestry and colorrectal cáncer risk in Colombia

Introducción. El cáncer colorrectal es una carga para la salud pública en Colombia y el mundo. Estudios de asociación genética han identificado regiones cromosómicas asociadas a esta enfermedad, mostrando riesgo variable entre poblaciones, debido a la historia demográfica y la ancestría genética. Objetivo. Estudiar el riesgo que aportan 20 marcadores al cáncer colorrectal en Colombia, empleando 955 casos y 972 controles del consorcio CHIBCHA, analizando conjuntamente el efecto de la ancestría genética global y local. Metodología. Las muestras se genotipificaron usando microarreglos Axyom Affymetrix LAT y CUSTOME, para obtener los genotipos genómicos globales, incluyendo 20 SNPs de riesgo. Los análisis estadísticos se realizaron en PLINK (asociaciones), ADMIXTURE (ancestría global), Elai (ancestría local) y R (modelos logísticos). Resultados. Once regiones cromosómicas resultaron asociadas presentando ORs entre 1.14 y 1.41 (p<0.05): 18q21.1, 19q13.11, 10p14, 14q.2.2, 20p12.3, 8q23.3, 6p21.2, 15q13.3 y 8q24.21. Una mayor ancestría europea se asoció con el riesgo a nivel global (OR=3.016, IC 95%:1.162-7.894, p=0.00325), y a nivel cromosómico local se detectaron las regiones 6q23.2 (ORajustado=1.378, IC95%: 1.202-1.580, Pajustado=4.2e-6) y 4p13 (ORajustado=1.301, IC95%:1.137-1.489; Pajustado=0.00013). Conclusiones. La ancestría podría considerarse un factor en la explicación de la susceptibilidad en Colombia, indicando que la mezcla genética de origen amerindio y europeo, influye en la estructura poblacional y explicaría las diferencias en la incidencia del CCR entre poblaciones latinas y europeas.

Introduction: Colorectal cancer is a public health burden in the world and Colombia. Recent genome wide association studies have identified chromosomal regions associated with the disease, depicting variable risk between populations, owing to the demographic history and genetic ancestry. Objective: We aimed to study the colorectal cancer risk in Colombia provided for 20 genetic markers, by using 955 cases and 972 controls from the CHIBCHA consortium, in the context of global and local genetic ancestry. Methodology: The samples were genotyped using Axyom Affymetrix LAT and CUSTOME array in order to obtain the global genome genotypes including 20 risk SNPs. Statistical analysis was performed in PLINK (associations), ADMIXTURE (global ancestry), Elai (local ancestry) and R language (logistic models). Results: Eleven chromosomal regions were associated with ORs ranging between 1.14-1.41 (p<0.05): 18q21.1, 19q13.11, 10p14, 14q.2.2, 20p12.3, 8q23.3, 6p21.2, 15q13.3 y 8q24.21. On average, a higher global European ancestry was associated with colorectal cancer risk (OR=3.016, IC 95%:1.162-7.894, p=0.00325). At the local chromosomal level two regions presented a significant increment of European ancestry 6q23.2 (OR adjusted=1.378, CI95%: 1.202-1.580, p adjusted =4.2e-6) and 4p13 (OR adjusted =1.301, CI95%:1.137-1.489; p adjusted =0.00013). Conclusions: Genetic ancestry can be considered as a relevant factor for the colorectal cancer susceptibility in Colombia. Both Native American and European ancestry are accounting for the most part of population structure in the sample we studied, which could explain the differences for the colorectal cancer incidence between Latin American and European populations.

Congenital hyperinsulinism in two siblings with ABCC8 mutation: same genotype, different phenotypes

SUMMARY Congenital hyperinsulinism (CHI) is a heterogenous disease caused by insulin secretion regulatory defects, being ABCC8/KCNJ11 the most commonly affected genes. Therapeutic options include diazoxide, somatostatin analogues and surgery, which is curative in focal CHI. We report the case of two siblings (born two years apart) that presented themselves with hypoketotic hyperinsulinemic persistent hypoglycemias during neonatal period. The diagnosis of diffuse CHI due to an ABCC8 compound mutation (c.3576delG and c.742C>T) was concluded. They did not benefit from diazoxide therapy (or pancreatectomy performed in patient number 1) yet responded to somatostatin analogues. Patient number 1 developed various neurological deficits (including epilepsy), however patient number 2 experienced an entirely normal neurodevelopment. We believe this case shows how previous knowledge of the firstborn sibling's disease contributed to a better and timelier medical care in patient number 2, which could potentially explain her better neurological outcome despite their same genotype.

ABCC3 Polymorphisms and mRNA Expression Influence the / Concentration of a Carboxylic Acid Metabolite in Patients on / Clopidogrel and Aspirin Therapy

Acetylsalicylic acid (ASA) and clopidogrel combined therapy has been reported to be beneficial in patients with acute coronary syndrome (ACS). Antiplatelet drug resistance, especially to clopidogrel, is a multifactorial phenomenon that affects a large number of ACS patients. The genetic contribution to this drug response is not fully elucidated. We investigated the relationship of ABC-type efflux subfamily C member 3 (ABCC3) polymorphisms and mRNA expression with plasma concentrations of clopidogrel, salicylic acid (SA) and a carboxylic acid metabolite (CAM). Clopidogrel, CAM and SA plasma concentrations were measured simultaneously by liquid chromatography-tandem mass spectrometry (LCMS/MS) from 83 ACS patients undergoing percutaneous coronary intervention. ABCC3 (rs757421, rs733392 and rs739923) and CYP2C19*2 (rs4244285) polymorphisms as well as mRNA expression were evaluated. A positive correlation was found between CAM concentrations and ABCC3 mRNA expression (r = 0.494, p < 0.0001). Patients carrying genotype AA (rs757421 variant) had higher CAM concentrations and ABCC3 mRNA expression as compared to those of GG + GA carriers (p = 0.017). A multiple linear regression analysis revealed that ABCC3 mRNA expression (p = 0.017), rs757421 AA genotype (p = 0.001), blood collection time (p = 0.018) and clopidogrel dose (p = 0.001) contributed to the concentration of CAM. No associations were observed for the CYP2C19*2 polymorphism. These results suggest that up-regulation of ABCC3 mRNA expression leads to increased plasma CAM levels through MRP3-mediated cell efflux. The ABCC3 rs757421 polymorphism may contribute to gene expression. Therefore, ABCC3 may be a potential biomarker for the response to clopidogrel.

ABCC3 Polymorphisms and mRNA expression influence the concentration of a carboxylic acid metabolite in patients on clopidogrel and aspirin therapy

Acetylsalicylic acid (ASA) and clopidogrel combined therapy has been reported to be beneficial in patients with acute coronary syndrome (ACS). Antiplatelet drug resistance, especially to clopidogrel, is a multifactorial phenomenon that affects a large number of ACS patients. The genetic contribution to this drug response is not fully elucidated. We investigated the relationship of ABC-type efflux subfamily C member 3 (ABCC3) polymorphisms and mRNA expression with plasma concentrations of clopidogrel, salicylic acid (SA) and a carboxylic acid metabolite (CAM). Clopidogrel, CAM and SA plasma concentrations were measured simultaneously by liquid chromatography-tandem mass spectrometry (LCMS/MS) from 83 ACS patients undergoing percutaneous coronary intervention. ABCC3 (rs757421, rs733392 and rs739923) and CYP2C19*2 (rs4244285) polymorphisms as well as mRNA expression were evaluated. A positive correlation was found between CAM concentrations and ABCC3 mRNA expression (r = 0.494, p < 0.0001). Patients carrying genotype AA (rs757421 variant) had higher CAM concentrations and ABCC3 mRNA expression as compared to those of GG + GA carriers (p = 0.017). A multiple linear regression analysis revealed that ABCC3 mRNA expression (p = 0.017), rs757421 AA genotype (p = 0.001), blood collection time (p = 0.018) and clopidogrel dose (p = 0.001) contributed to the concentration of CAM. No associations were observed for the CYP2C19*2 polymorphism...

Genetic variants associated with addictive behavior in Colombianaddicted and non-addicted to heroin or cocaine / Variantes genéticas asociadas con conducta adictiva en colombianos adictos y no adictos a heroína o cocaína

Objective:Determine the prevalence and compare somegenetic markers involved in addictive behavior in a groupof addicts to derivative of coca (cocaine/crack) or heroinand a control group of non-addicted people matched forgender, age and ethnicity.Methods:A 120 addicts and 120 non-addicts Colombianmale were surveyed and genotyped for 18 polymorphismof the OPRM1, DRD2, DRD4, SLC6A3, SLC6A4, ABCB1,DβH and CYP2B6 genes. For the identification of allelesmarkers were used mini-sequencing and fragment multi-plex PCR techniques; ethnicity of cases and controls wasanalyzed with 61 AIMs.Results:The age of onset use of heroin or coca derivati-ves (cocaine/crack) was 16,5±6 years and 99,2 percent of themconsume several illicit drugs. It showed that controlsand addicts belong to the same ethnic group. Significantdifferences between addicts and controls in relation toschooling, marital status, social security family historyof substance abuse (p<0,001), Int8-VNTR SLC6A3 gene(p=0,015) and SNP 3435C>T ABCB1 gene (p=0,001) werefound.Conclusion:The present results indicate that the VNTR-6R polymorphism of the gene SLC6A3 and the genoty-pe 3435CC in the ABCB1 gene, are both associated withaddictive behavior to heroin or cocaine.

Novel genes detected by transcriptional profiling from whole-bloodcells in patients with early onset of acute coronary syndrome

Background: Genome-wide expression analysis using microarrays has been sed as a research strategy to discovery new biomarkers and candidate genes for a number of diseases. We aim to find new biomarkers for the prediction of acute coronary syndrome (ACS) with a ifferentially expressed mRNA profiling approach using whole genomic expression analysis in a peripheral blood cell model from patients with early ACS.Methods and results: This study was carried out in two phases. On phase 1 a restricted clinical criteria (ACS-Ph1, n = 9 and CG-Ph1, n = 6) was used in order to select potential mRNA biomarkers candidates. A subsequent phase 2 study was performed using selected phase 1 markers analyzed by RT-qPCR using alarger and independent casuistic (ACS-Ph2, n = 74 and CG-Ph2, n = 41). A total of 549 genes were found to be differentially expressed in the first 48 h after the ACS-Ph1. Technical and biological validation further confirmed that ALOX15, AREG, BCL2A1, BCL2L1, CA1, COX7B, ECHDC3, IL18R1, IRS2, KCNE1, MMP9, MYL4 and TREML4, are differentially expressed in both phases of this study.Conclusions: Transcriptomic analysis by microarray technology demonstrated differential expression during a 48 h time course suggesting a potential use of some of these genes as biomarkers for very early stages of ACS, as well as for monitoring early cardiac ischemic recovery.

Differentiation of african components of ancestry to stratify groups in a Case–control study of a brazilian urban population

Background: Balancing the subject composition of case and control groups to create homogenous ancestries between each group is essential for medical association studies. Methods: We explored the applicability of single-tube 34-plex ancestry informative markers (AIM) single nucleotide polymorphisms (SNPs) to estimate the African Component of Ancestry (ACA) to design a future case-control association study of a Brazilian urban sample. Results: One hundred eighty individuals (107 case group; 73 control group) self-described as white, brown-intermediate or black were selected. The proportions of the relative contribution of a variable number of ancestral population components were similar between case and control groups. Moreover, the case and control groups demonstrated similar distributions for ACA 0.50 categories. Notably a high number of outlier values (23 samples) were observed among individuals with ACA <0.25. These individuals presented a high probability of Native American and East Asian ancestral components; however, no individuals originally giving these self-described ancestries were observed in this study. Conclusions: The strategy proposed for the assessment of ancestry and adjustment of case and control groups for an association study is an important step for the proper construction of the study, particularly when subjects are taken from a complex urban population. This can be achieved using a straight forward multiplexed AIM-SNPs assay of highly discriminatory ancestry markers.

Pharmacogenetics of OATP Transporters Reveals That SLCO1B1 c.388A>G Variant Is Determinant of Increased Atorvastatin Response

Aims: The relationship between variants in SLCO1B1 and SLCO2B1 genes and lipid-lowering response to atorvastatin was investigated. Material and Methods: One-hundred-thirty-six unrelated individuals with hypercholesterolemia were selected andOPEN ACCESStreated with atorvastatin (10 mg/day/4 weeks). They were genotyped with a panel of ancestry informative markers for individual African component of ancestry (ACA) estimation by SNaPshot® and SLCO1B1 (c.388A>G, c.463C>A and c.521T>C) and SLCO2B1 (−71T>C) gene polymorphisms were identified by TaqMan® Real-time PCR. Results: Subjects carrying SLCO1B1 c.388GG genotype exhibited significantly high low-density lipoprotein (LDL) cholesterol reduction relative to c.388AA+c.388AG carriers (41 vs. 37%, p = 0.034). Haplotype analysis revealed that homozygous of SLCO1B1*15 (c.521C and c.388G) variant had similar response to statin relative to heterozygous and non-carriers. A multivariate logistic regression analysis confirmed that c.388GG genotype was associated with higher LDL cholesterol reduction in the study population (OR: 3.2, CI95%:1.3–8.0, p G polymorphism causes significant increase in atorvastatin response and may be an important marker for predicting efficacy of lipid-lowering therapy.

Variabilidad genética en 17 microsatélites del Cromosoma Y en dos poblaciones nativas de Argentina (Tobas, Collas) / Genetic Variability in 17 Y-STR loci of a native population from Argentine (Tobas, Collas)

Se analizan 17 marcadores microsatélites del cromosoma Y del tipo Short Tandem Repeats (STRs) (DYS19,DYS3891, DYS38911, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, y GATA H4)en dos poblaciones nativas de las regiones Norte y Noroeste de la Argentina (Tobas y Collas)