Abstract Objective: We evaluated whether cholesteryl ester transfer protein (CETP) gene polymorphisms are associated with the presence of coronary artery disease (CAD) and/or restenosis in patients with coronary stent. Methods: Two polymorphisms of the CETP gene [−971 A/G (rs4783961), and Taq1B A/G (rs708272)] were genotyped by 5'exonuclease TaqMan assays in 219 patients with CAD (66 patients with restenosis and 153 without restenosis) and 607 control individuals. Results: The distribution of polymorphisms was similar in patients with and without restenosis. However, when the whole group of patients (with and without restenosis) was compared to healthy controls, under dominant model, the G allele of the Taq1B A/G polymorphism was associated with increased risk of CAD (odds ratio [OR] = 1.48, pCDom = 0.032). In the same way, under codominant, dominant, and additive models, the A allele of the −971 A/G polymorphisms was associated with an increased risk of developing CAD (OR = 2.03, pCCo-dom = 0.022, OR = 1.83, pCDom = 0.008, and OR = 1.39, pCAdd = 0.011, respectively). In addition, the linkage disequilibrium showed that the “AG” haplotype was associated with increased risk of developing CAD (OR = 1.28, p = 0.03). Conclusion: This study demonstrates that CETP Taq1B A/G and CETP −971 A/G polymorphisms are associated with an increased risk of developing CAD, but no association with restenosis was observed.

Resumen Objetivo: Evaluamos si los polimorfismos del gen CETP están asociados con la presencia de enfermedad arterial coronaria (EAC) y/o restenosis en pacientes con stent coronario. Métodos: En este estudio se genotiparon dos polimorfismos del gen CETP [−971 A/G (rs4783961) y Taq1B A/G (rs708272)] mediante ensayos de 5'exonucleasa TaqMan en 219 pacientes con EAC (66 pacientes con restenosis y 153 sin restenosis), y 607 individuos de control. Resultados: La distribución de polimorfismos fue similar en pacientes con y sin restenosis. Sin embargo, cuando se comparó todo el grupo de pacientes (con y sin restenosis) con controles sanos, bajo el modelo dominante el alelo G del polimorfismo Taq1B A/G se asocia con un mayor riesgo de EAC (OR = 1.48, pCDom = 0.032). De la misma manera, bajo los modelos co-dominante, dominante y aditivo, el alelo A de los polimorfismos −971 A/G se asocia con un mayor riesgo de desarrollar EAC (OR = 2.03, pCCo-dom = 0.022, OR = 1.83, pCDom = 0,008 y OR = 1.39, pCAdd = 0.011, respectivamente). Adicionalmente, el desequilibrio de ligamiento mostró que el haplotipo “AG” se asocia con un mayor riesgo de desarrollar EAC (OR = 1.28, p = 0.03). Conclusión: En resumen, este estudio demuestra que los polimorfismos CETP Taq1B A/G y CETP −971 A/G están asociados con un mayor riesgo de desarrollar CAD, pero no se observó asociación con restenosis.

Abstract Objective: To assess the relationship of metabolic syndrome (MetS) and Lp(a) with subclinical atherosclerosis (CAC) in Mexican adults. Method: Clinical, biochemical and tomographic data of visceral, subcutaneous, hepatic abdominal fat and CAC were evaluated in 953 women and men. Lp(a) was determined by nephelometry and MetS was diagnosed according to ATP III criteria. Multivariate logistic regression analysis was performed to determine the independent association of these variables with CAC. Results: Age, weight, body mass index, systolic and diastolic blood pressure, volumes of visceral, subcutaneous and hepatic abdominal fat, lipids, glucose, insulin and HOMA-RI were significantly higher in subjects with MetS. The median Lp(a) was lower in subjects with MetS compared to subjects without MetS (3.7 [IR: 2.3-9.2 vs. 5.9 [IR: 2.5-13.1) mg/dL; p < 0.01). The number of components and the MetS were inversely associated with the elevated Lp(a) (> 30 mg / dL). The presence of MetS was associated with a CAC risk >0 (OR: 2.19, [95% CI (1.64-2.94)]; p < 0.001), independently of elevated Lp(a). The components of MetS that were independently associated with the presence of CAC > 0 UA were glycaemia > 100 mg/dL (OR 2.42, [95% CI (1.7-3.4)]; p < 0.0001) and high blood pressure (OR 2.14 [95% CI (1.5-3.1)]; p < 0.0001). Conclusions: In Mexican population there is an inverse association between Lp(a) levels and MetS. The MetS and its components were associated with subclinical atherosclerosis. The high prevalence of obesity, diabetes, high blood pressure high triglycerides and low HDL-C, characteristics of Mexican population could explain the differences with other populations.

Resumen Objetivo: Investigar la asociación del síndrome metabólico y la lipoproteína(a) [Lp(a)] con el riesgo de aterosclerosis subclínica en adultos mexicanos. Método: En 953 mujeres y hombres se evaluaron datos clínicos, bioquímicos y tomográficos de grasa abdominal visceral, subcutánea, hepática y calcio arterial coronario. La Lp(a) se determinó mediante nefelometría y el síndrome metabólico se diagnosticó con los criterios del Adult Treatment Panel III. La asociación independiente de estas variables con el calcio arterial coronario se obtuvo con análisis de regresión logística multivariada. Resultados: La edad, el peso, el índice de masa corporal, la presión arterial sistólica y diastólica, los volúmenes de grasa abdominal, los lípidos, la glucosa, la insulina y el índice de resistencia a insulina fueron significativamente mayores en los sujetos con síndrome metabólico, mientras que la mediana de Lp(a) fue más baja en comparación con los sujetos sin el síndrome (3.7 [rango intercuartílico (RIC): 2.3-9.2 vs. 5.9 [RIC: 2.5-13.1) mg/dl; p < 0.01). El número de componentes y el síndrome metabólico se asociaron inversamente con la Lp(a) elevada (> 30 mg/dl). La presencia de síndrome metabólico se asoció con un riesgo de calcio arterial coronario > 0 (odds ratio [OR]: 2.19; intervalo de confianza del 95% [IC95%]: 1.64-2.94; p < 0.001), independientemente de la Lp(a) elevada. La glucemia > 100 mg/dl (OR: 2.42; IC95%: 1.7-3.4; p < 0.0001) y la presión arterial elevada (OR: 2.14; IC95%: 1.5-3.1; p > 0.0001) se asociaron con calcio arterial coronario > 0. Conclusiones: En población mexicana existe una asociación inversa entre la concentración de Lp(a) y el síndrome metabólico. Este y sus componentes se asociaron positivamente con aterosclerosis subclínica. La elevada prevalencia de obesidad, diabetes, hipertensión arterial, triglicéridos elevados y concentración de colesterol unido a lipoproteínas de alta densidad que caracterizan a la población mexicana pudieran explicar las diferencias con otras poblaciones.

ABSTRACT Background: Lipoprotein(a) [Lp(a)] levels are genetically determined; high levels are a risk factor for coronary disease, although their association with coronary artery calcium (CAC) is controversial. Objective: The objective of the study was to assess the association of LPA gene polymorphisms with CAC in a Mexican Mestizo population. Methods: We included 1594 subjects 35-70 years old. Six polymorphisms of the LPA gene were analyzed. CAC score was determined by tomography and Lp(a) serum levels by immunonephelometry. The association of LPA polymorphism with CAC and Lp(a) was evaluated by logistic regression. Results: The prevalence of Lp(a) ≥30 mg/dL was 10%, and of CAC >0 was 26.9%. Three polymorphisms were associated with high Lp(a) levels: rs10455872-G (p = 0.013), rs6907156-T (p = 0.021), and rs7765803-C (p = 0.001). Homozygotes (CC) for the rs7765803 variant compared with the G allele (CG + GG) carriers had higher Lp(a) levels (8.9 [3.3-23.9] vs. 4.9 [2.3-11.2] mg/dL; p = 0.015) and higher prevalence of CAC >0 (36.5% vs. 26.3%, p = 0.045) and were associated with CAC > 0 (odds ratio = 1.7, 95% confidence interval: 1.06-2.7; p < 0.026). The other polymorphisms were not associated with CAC. Conclusions: This is the first study to demonstrate in a Mexican Mestizo population that carriers of the rs7765803-C allele of LPA gene have 2.6 times greater risk for high Lp(a) values and 1.7 times higher risk for coronary artery disease.

ABSTRACT Background: Previous studies have shown an association between polymorphisms of the BAT1-NF-κB inhibitor-like-1 (NFKBIL1)-LTA genomic region and susceptibility to myocardial infarction and acute coronary syndrome (ACS). Objective: The objective of the study was to study the role of three polymorphisms in the BAT1, NFKBIL1, and LTA genes on the susceptibility or protection against ACS; we included a group of cases-controls from Central Mexico. Methods: The BAT1 rs2239527C/G, NFKBIL1 rs2071592T/A, and LTA rs1800683G/A polymorphisms were genotyped using a 5’ TaqMan assay in a group of 625 patients with ACS and 617 healthy controls. Results: Under a recessive model, the BAT1 -23C/G (rs2239527) polymorphism showed an association with protection against ACS (odds ratio = 0.56, and p-corrected = 0.019). In contrast, the genotype and allele frequencies of the NFKBIL1 rs2071592T/A and LTA rs1800683G/A polymorphisms were similar between ACS patients and controls and no association was identified. Conclusion: Our data suggest an association between the BAT1 -23C/G polymorphism and protection against ACS in Mexican patients.

Abstract Polymorphisms in the LPA gene have been associated with aortic valve calcification (AVC). There are wide differences in the allelic frequencies, Lp(a) levels, and the association with AVC among ethnic groups. The aim of this study was to determine the association of the LPA gene polymorphisms with Lp(a) levels and risk of developing AVC, in Mexican-Mestizos population. Six LPA polymorphisms (rs10455872, rs7765803, rs6907156, rs1321195, rs12212807 and rs6919346) were genotyped by TaqMan assays in 1,265 individuals without premature coronary artery disease. The presence of AVC was determined by computed tomography. The association of the LPA polymorphisms with AVC, Lp(a), and other cardiovascular risk factors (CVRF) was evaluated using logistic regression analysis. Compared to AA genotype, subjects with AG+GG genotypes had high prevalence of Lp(a) ≥ 30 mg/dL (7.1% vs. 23.7%, p<0.001) and AVC (19.0% vs. 29.4%, p=0.007). In a model adjusted for several CVRF, the LPA rs10455872-G allele was associated with high Lp(a) levels and AVC. Carriers of G allele had a high risk of Lp(a) ≥ 30 mg/dL (OR= 3.86, CI 95%: 2.2 - 6.7, p=0.001) and AVC (OR= 2.54, CI 95%: 1.56 - 4.14, p=0.001), independently of other CVRF. In this population, carriers of rs10455872-G allele had 3.86 and 2.54 higher risk of Lp(a) ≥ 30 mg/dL or presence of AVC, respectively.

Abstract Background Vasovagal syncope (VVS) is a frequent clinical condition in which a genetic background seems to be implicated. Considering that the adrenergic receptors (ARs) may play a role in VVS, the present study has as principal aim to determine if the α- and β-AR (ADRA and ADRB) gene polymorphisms are associated with an increased risk to have a positive head-up tilt table (HUTT) test in patients with VVS. Methods: Nine polymorphisms in the ADRA1A (rs1048101, rs1383914, rs574584, and rs573542), ADRB1 (rs1801252 and rs1801253), ADRB2 (rs1042713 and rs1042714), and ADRB3 (rs4994) genes were analyzed using the 5’ exonuclease TaqMan genotyping assay in a group of 134 patients with VVS. Results Under different models, the rs1801252 (OR = 8.63, 95% CI: 0.95-78.72, Precessive = 0.02), rs1042713 (OR = 1.94, 95% CI: 1.02-3.66, Padditive = 0.04), and rs4994 (OR = 2.46, 95% CI: 1.01-6.01, Pdominant = 0.042 and OR = 2.62, 95% CI: 1.04-6.63, Pover-dominant = 0.03) polymorphisms were associated with increased risk for a positive HUTT. All models were adjusted for statistically significant covariates. Conclusion These results suggest that some polymorphisms of the β-AR genes could contribute to a positive tilt test in patients with VVS.

Abstract We examined the role of UCP gene polymorphisms as susceptibility markers for premature coronary artery disease (pCAD). The UCP2 Ala55Val (C/T rs660339), UCP2 -866G/A (rs659366), and UCP3 -55C/T (rs1800849) polymorphisms were genotyped in 948 patients with pCAD, and 763 controls. The distribution of the UCP2 A55V (C/T rs660339) and UCP3 -55 (rs1800849) was similar in patients and controls. However, under a recessive model, the UCP2 -866 (rs659366) A allele was associated with increased risk of developing pCAD (OR = 1.43, Pc = 0.003). On the other hand, patients with pCAD and UCP2 A55V (rs660339) TT showed high levels of visceral abdominal fat (VAF) (Pc = 0.002), low levels of subcutaneous abdominal fat (SAF) (Pc = 0.001) and high VAT/SAT ratio (Pc < 0.001). Also, patients with UCP2 -866 (rs659366) AA showed increased levels of VAF (Pc = 0.003), low levels of SAF (Pc = 0.001) and a high VAT/SAT ratio (Pc = 0.002), whereas patients with the UCP3 -55 (rs1800849) TT presented high levels of VAF (Pc = 0.002). The results suggest the association of the UCP2 -866 (rs659366) polymorphism with risk of developing pCAD. Some polymorphisms were associated with abdominal fat levels and cardiovascular risk factors.

Abstract: Objective: The prevalence of coronary artery calcification (CAC), a specific marker of atherosclerosis, is unknown in Mexico. Our aim was to investigate the prevalence and quantity of CAC and their association with cardiovascular risk factors in a Mexican population. Methods: CAC was measured by multidetector computed tomography in asymptomatic subjects who participated in the Genetics of Atherosclerotic Disease study. Cardiovascular risk factors and medication were recorded. Results: The sample included 1,423 individuals (49.5% men), aged 53.7 ± 8.4 years. Those with CAC showed a higher prevalence of dyslipidaemia, diabetes, hypertension, and other risk factors. The prevalence of CAC > 0 Agatston units was significantly higher among men (40%) than among women (13%). Mean values of CAC score increased consistently with increasing age and were higher in men than women in each age group. Age and high low density lipoprotein cholesterol were independently associated with prevalence of CAC > 0 in men and women, while increasing systolic blood pressure in women and age in both genders showed an independent association with CAC extension. Conclusions: In the Mexican population the prevalence and extent of CAC were much higher in men than in women, and strongly increased with age. Independent predictors of CAC prevalence were age and low density lipoprotein cholesterol (LDL-C).

Resumen: Objetivo: La prevalencia de calcificación arterial coronaria (CAC), marcador específico de aterosclerosis, no es conocida en México. Nuestro objetivo fue investigar la prevalencia y extensión de CAC y su asociación con factores de riesgo cardiovascular en población mexicana. Métodos: La CAC fue medida por tomografía computarizada multidetector en individuos asintomáticos que participaron en el estudio Genética de la Enfermedad Aterosclerosa. Los factores de riesgo cardiovascular y los medicamentos fueron registrados. Resultados: La muestra incluyó 1,423 individuos (49.5% hombres), con una edad de 53.7 ± 8.4 años. Los portadores de CAC mostraron prevalencias más altas de dislipidemia, diabetes, hipertensión y otros factores de riesgo. La prevalencia de CAC > 0 unidades Agatston fue de 27%, significativamente más alta en hombres (40%) que en mujeres (13%). Los valores medios del puntaje de CAC aumentaron consistentemente con la edad y fueron más altos en hombres que en mujeres en todos los grupos etarios. La edad y el c-LDL elevado se asociaron de manera independiente con la prevalencia de CAC > 0 en hombres y mujeres, mientras que la presión arterial sistólica en las mujeres, y el incremento de la edad en ambos géneros mostró una asociación independiente con la severidad de CAC. Conclusiones: En población mexicana la prevalencia y la extensión de CAC fueron mucho más altas en hombres que en mujeres y aumentaron consistentemente con la edad. Los predictores independientes de la prevalencia de CAC fueron la edad y el c-LDL.

Abstract: Objetive: The prevalence of aortic valve calcification (AVC), strongly influenced by ethnicity, is unknown in Mexican population. The aim of this study was to investigate the prevalence of AVC and its associations with cardiovascular risk factors and coronary artery calcification (CAC), in Mexican subjects. Methods: In 1,267 subjects (53% women) without known coronary heart disease, aged 35 to 75 years, AVC and CAC were assessed by multidetector-computed tomography using the Agatston score. Cardiovascular risk factors were documented in all participants. The associations of AVC with CAC and risk factors were assessed by multivariable logistic regression analyses. Results: The overall prevalence of AVC and CAC was 19.89% and 26.5%, respectively. AVC and CAC increased with age and were found more frequently in men (25.5% and 37.1%, respectively) than in women (14.9% and 13.0%, respectively). AVC was observed in only 8.5% of subjects wit-hout CAC, while those with CAC 1-99, 100-399, and > 400 Agatston units had AVC prevalences of 36.8%, 56.8%, and 84.0%, respectively. The multivariable logistic regression analyses, adjusted for age, gender, obesity, physical inactivity, hypertension, dyslipidemia and high insulin levels, showed that the presence of CAC (OR [CI95%]: 3.23 [2.26-4.60]), obesity (1.94 [1.35-2.79]), male gender (1.44 [1.01-2.05]) and age (1.08 [1.03-1.10]), were significant independent predictors of AVC. Conclusion: Prevalence of AVC is high and significantly associated with atherosclerotic risk factors and CAC in this Mexican population.

Resumen: Objetivo: La prevalencia de calcificación valvular aórtica (CVA) tiene influencia importante de la etnia y se desconoce en población mexicana. Nuestro objetivo fue investigar la prevalencia de CVA y sus asociaciones con factores de riesgo cardiovascular y calcificación arterial coronaria (CAC). Método: En 1,267 sujetos (53% mujeres) sin enfermedad coronaria conocida y con edad de 35 a 75 años, la CVA y la CAC se evaluaron mediante tomografía computada multidetector, utilizando el método de Agatston. Los factores de riesgo cardiovascular se documentaron en todos los participantes. Las asociaciones de CVA con CAC y factores de riesgo se estimaron usando el análisis de regresión logística múltiple. Resultados: La prevalencia global de CVA y CAC fue del 19.89% y del 26.5%, respectivamente. Ambas condiciones aumentaron con la edad y se encontraron con mayor frecuencia en hombres (25.5 y 37.1%, respectivamente) que en mujeres (14.9 y 13%, respectivamente). La CVA se observó en únicamente el 8.5% de los sujetos sin CAC, mientras que en aquellos con CAC 1-99, 100-399 y > 400 unidades Agatston, las prevalencias fueron del 36.8, 56.8 y 84%, respectivamente. El análisis de regresión logística múltiple ajustado por edad, género, obesidad, inactividad física, hipertensión, dislipidemia y valores altos de insulina, mostró que la presencia de CAC (RM [IC95%]: 3.23 [2.26-4.60]), obesidad (1.94 [1.35-2.79]), género masculino (1.44 [1.01-2.05]) y edad (1.08 [1.03-1.10]), fueron predictores independientes y significativos de la CVA. Conclusiones: La prevalencia de CVA es alta y se asocia significativamente con factores de riesgo aterosclerótico y CAC en población mexicana.

Hereditary sudden cardiac death syndromes comprise a wide range of diseases resulting from alteration in cardiac ion channels. Genes involved in these syndromes represent diverse mutations that cause the altered encoding of the diverse proteins constituting these channels, thus affecting directly the currents of the corresponding ions. In the present article we will briefly review how to arrive to a clinical diagnosis and we will present the results of molecular genetic studies made in Mexican subjects attending the SCD Syndromes Clinic of the National Institute of Cardiology of Mexico City.

Los síndromes hereditarios de muerte súbita cardíaca comprenden una amplia gama de enfermedades resultantes de la alteración en los canales iónicos cardíacos. Los genes implicados en estos síndromes presentan mutaciones que causan alteraciones de las diversas proteínas que constituyen estos canales y que, por lo tanto, afectan directamente a las diferentes corrientes iónicas. En el presente artículo se revisa brevemente la forma de llegar a un diagnóstico clínico de dichos síndromes y se presentan los resultados de los estudios genéticos moleculares realizados en sujetos mexicanos que asisten a la Clínica de Síndromes Hereditarios de Muerte Súbita del Instituto Nacional de Cardiología Ignacio Chávez.

The Andersen-Tawil syndrome is a cardiac ion channel disease that is inherited in an autosomal dominant way and is classified as type 7 of the congenital long QT syndromes. Affected gene is KCNJ2, which forms the inward rectifier potassium channel designated Kir2.1. This protein is involved in stabilizing the resting membrane potential and controls the duration of the action potential in skeletal muscle and heart. It also participates in the terminal repolarization phase of the action potential in ventricular myocytes and is a major component responsible for the correction in the potassium current during phase 3 of the action potential repolarization. Kir 2.1 channel has a predominant role in skeletal muscle, heart and brain. Alterations in this channel produce flaccid paralysis, arrhythmias, impaired skeletal development primarily in extremities and facial area. In this review we address the disease from the point of view of clinical and molecular diagnosis with emphasis on cardiac manifestations.

El síndrome de Andersen-Tawil resulta de la alteración de canales de potasio, se hereda de forma autosómica dominante y se cataloga como el tipo 7 de los síndromes de QT largo congénitos. El gen afectado es el KCNJ2, el cual codifica la proteína Kir2.1 que forma el canal de potasio rectificador interno («inward rectifier»). Este canal interviene en la estabilización del potencial de membrana en reposo y controla la duración del potencial de acción en el sistema musculoesquelético y cardíaco. En miocitos ventriculares, es un componente responsable de la rectificación de la corriente de potasio en la fase 3 del potencial de acción. Debido a que Kir2.1 está presente en el sistema musculoesquelético, corazón y cerebro, las alteraciones de esta proteína dan origen a las principales características del síndrome: parálisis flácida, arritmias ventriculares y alteraciones leves a moderadas en el desarrollo del esqueleto, especialmente en manos y pies. En la presente revisión se aborda esta enfermedad desde el punto de vista del diagnóstico clínico y molecular con énfasis en sus manifestaciones cardíacas.

Objective: The objective of this study was to establish the role of the TLR-4 gene polymorphisms in individuals in risk of developing ACS. Methods: The study included 457 Mexican patients with ACS and 283 control individuals. The TLR-4 Asp299Gly and TLR-4 Thr399Ile single nucleotide polymorphisms were genotyped using 5' exonuclease TaqMan genotyping assays on an 7900HT Fast real-time PCR system according to manufacturer's instructions (Applied Biosystems, Foster City, USA). Results: The results obtained in this study showed that the frequency of the two polymorphisms (TLR-4 Asp299Gly and TLR-4 Thr399Ile) studied were similar between patients with ACS and healthy controls. Multiple logistic regression analysis showed that the largest risk factor for ACS development was given by smoking (11.88-fold increased risk), hypertension (4.32-fold increased risk), type II diabetes (3.44-fold increased risk), gender (2.32-fold increased risk), and dyslipidemia (1.52-fold increased risk). Conclusion: The Asp299Gly and Thr399Ile polymorphisms were not associated with susceptibility to ACS in the Mexican population.

Objetivo: El objetivo de este estudio fue establecer el papel de los polimorfismos del gen TLR-4 en individuos en riesgo de desarrollar síndrome coronario agudo (SCA). Métodos: El estudio incluyó a 457 pacientes mexicanos con SCA y 283 individuos como grupo control. Los polimorfismos de un solo nucleótido TLR-4 Asp299Gly y TLR-4 Thr399Ile fueron determinados usando ensayos TaqMan 5' exonucleasa en un equipo tiempo real 7900HT (Fast real-time PCR system) de acuerdo con instrucciones del fabricante Applied Biosystems, Foster City, EE.UU. Resultados: Los resultados obtenidos mostraron que las frecuencias de los 2 polimorfismos (TLR-4Asp299Gly y TLR-4 Thr399Ile) estudiados fueron similares entre pacientes con SCA e individuos control. No obstante, el análisis de regresión logística mostró que los factores de mayor riesgo para desarrollar SCA se debieron a tabaquismo (incrementa 11.88 veces el riesgo), hipertensión (incrementa 4.32 veces el riesgo), diabetes tipo 2 (incrementa 3.44 veces el riesgo), género (incrementa 2.32 veces el riesgo), y la dislipidemia (incrementa 1.52 veces el riesgo). Conclusión: Determinamos que los polimorfismos Asp299Gly y Thr399Ile no se asocian con la susceptibilidad al SCA en la población mexicana.

Objective: The aim of this study was to test for association between MHC2TA gene polymorphisms and risk for restenosis after coronary stent placement in a group of Mexican patients. Methods: The MHC2TA-168A>G (rs3087456), 1614C>G (rs4774), and 2536G>A (rs2229320) single nucleotide polymorphisms were genotyped using 5' exonuclease TaqMan genotyping assays in a group of 202 patients, who underwent coronary artery stenting. Basal and procedure coronary angiography were analyzed, looking for angiographic predictors of restenosis and follow-up angiography was performed to screen for binary restenosis. Results: The results obtained in this study showed that the frequency of the three polymorphisms studied was similar in patients with and without restenosis. Univariate analysis showed that the use of drug-eluting stent (DES) reduces the risk of developing restenosis (p < 0.001, OR = 0.26). In contrast, the diameter< 2.5 mm of the stent and bifurcations increased the risk of developing restenosis (p = 0.049, OR = 1.74 and p = 0.041, OR = 1.8). Conclusion: The present study suggests that the MHC2TA polymorphisms are not involved in the risk of developing restenosis after coronary stent placement.

Objetivo: El propósito de este estudio fue evaluar la asociación de los polimorfismos del gen MHC2TA y el riesgo de desarrollar reestenosis, después del implante de stent coronario en un grupo de pacientes mexicanos. Métodos: Los polimorfismos de un solo nucleótido MHC2TA-168A>G (rs3087456), 1614C>G (rs4774) y 2536G>A (rs2229320), se determinaron en un grupo de 202 pacientes tratados con stent coronario. Los polimorfismos fueron evaluados utilizando ensayos de genotipificacion Taq-Man 5' exonucleasa. El procedimiento basal y la búsqueda de predictores de reestenosis fueron analizados por medio de angiografía coronaria, y seguimiento angiográfico con el fin de detectar reestenosis binaria. Resultados: Los resultados obtenidos en este estudio mostraron que la distribución génica de los tres polimorfismos estudiados fue muy similar, en pacientes con o sin reestenosis. Sin embargo, el análisis univariado mostró que el uso de los stent medicados reducen el riesgo de desarrollar reestenosis (p < 0.001, OR = 0.26). En contraste, con las bifurcaciones y el diámetro < 2.5 mm del stent que se incrementa el riesgo de desarrollar reestenosis (p = 0.049, OR = 1.74 y p = 0.041, OR = 1.8). Conclusión: El presente estudio sugiere que los polimorfismos del gen MHC2TA no están asociados con el riesgo de desarrollar reestenosis, después del implante de stent coronario.

The arterial hypertension is considered to be the main risk factor for myocardial infarction, heart failure, ventricular arrhythmias, kidney failure, blindness and other diseases. Arterial hypertension is a multifactorial disease derived from environmental, genetic, gender and ethnic factors. In recent years, the World Health Organization estimated that approximately 17.5 million of deaths were due to cardiovascular diseases worldwide and that this pathology will become the leading cause of death in the next decade. Data from the National Survey of Mexican Ministry of Health (2006), reported approximately 17 million hypertensive adults, equivalent to a prevalence of 30.8% among Mexican population. As a consequence, hypertension represents the leading cause of morbidity from 2000 to 2005 and is increasing in recent years. However, studies have failed to clearly identify the molecular and genetic mechanisms of this pathology so far. Nevertheless, using the new technologies for analysis of variants in the genome, several genes in different loci that confer susceptibility to develop hypertension have been identified. In this review we compared the different studies in genetics and genomics of the hypertension that have been made worldwide and in Mexico, with the aim of identifying important genes involved in susceptibility to the development of this pathology.

La hipertensión arterial es considerada la principal causa de riesgo para el desarrollo de infarto agudo al miocardio, falla cardiaca, arritmia ventricular, nefropatía, ceguera, entre otras. La hipertensión arterial es una enfermedad multifactorial en la que participan factores ambientales, genéticos e intrínsecos como raza y género. La Organización Mundial de la Salud ha estimado que la prevalencia de la hipertensión se incrementará drásticamente, de modo que en la próxima década será la primera causa de muerte a nivel mundial, debido al elevado número de muertes (17.5 millones) por enfermedades cardiovasculares registradas a nivel mundial. No obstante, los datos publicados en la Encuesta Nacional de la Secretaría de Salud en 2006, señalan aproximadamente 17 millones de hipertensos en población adulta y una prevalencia de 30.8%, cifra que indica que la hipertensión arterial aumentó su morbilidad del año 2000 al 2005. Sin embargo, poco se ha logrado en la comprensión de los mecanismos moleculares y genéticos involucrados en el desarrollo de esta patología y en consecuencia su prevalencia sigue aumentando drásticamente. Con el uso de las nuevas tecnologías para el análisis de las variantes en el genoma, se han identificado algunos genes en diferentes loci que confieren susceptibilidad al desarrollo de hipertensión arterial. La finalidad de esta revisión es hacer una comparación entre los diferentes estudios en genética y genómica relacionados con esta patología a nivel mundial y en nuestro país, con la finalidad de identificar genes clave que participen en la susceptibilidad al desarrollo de la hipertensión arterial.