The branched-chain amino acid transaminase 1 -23c/g polymorphism confers protection against acute coronary syndrome

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.

Role of genetic variability in Mendelian and multifactorial diseases

The first draft of the human genome sequencing published in 2001 reported a large number of single nucleotide polymorphisms (SNPs). Given that these polymorphisms could practically represent all the variability involved in the susceptibility, protection, severity, among other aspects, of various common diseases, as well as in their response to medications, it was thought that they might be “the biomarkers of choice” in personalized genomic medicine. With the new information obtained from the sequencing of a larger number of genomes, we have understood that SNPs are only an important part of the genetic markers involved in these traits. In addition to SNPs, other variants have been identified, such as insertions/deletions (INDELs) and copy number variants (CNVs), which – in addition to classic variable number tandem repeats (VNTRs) and short tandem repeats (STRs) – originate or contribute to the development of diseases. The use of these markers has served to identify regions of the genome involved in Mendelian diseases (one gene-one disease) or genes directly associated with multifactorial diseases. This review has the purpose to describe the role of STRs, VNTRs, SNPs, CNVs and INDELs in linkage and association studies and their role in Mendelian and multifactorial diseases.

MicroRNA en enfermedades autoinmunes / MicroRNA in autoimmune diseases

Resumen Los microRNA (miRNA) son pequeños RNA no codificantes de aproximadamente 17 a 24 nucleótidos de longitud, los cuales se unen complementaria y principalmente en las regiones 3' UTR (región no traducida) de diversos RNA mensajeros (mRNA, messenger RNA). Su función general es regular negativamente la expresión génica a nivel postranscripcional, inhibiendo la traducción. Perfiles de expresión de miRNA alterados han sido identificados en diferentes líquidos, células y tejidos humanos afectados con diversas enfermedades autoinmunes y algunos se han propuestos potencialmente como biomarcadores de diagnóstico, pronóstico, actividad, etcétera, en estas patologías. Adicionalmente, variantes comunes del genoma humano, denominados polimorfismos de un solo nucleótido (SNP, single nucleotide polymorphisms) localizados en genes de miRNA han sido asociados con susceptibilidad, gravedad, y actividad en estas enfermedades. El objetivo de esta revisión es describir la biogénesis de los miRNA, su función, así como los perfiles de expresión y SNP en genes de miRNA asociados con diversas enfermedades autoinmunes, incluyendo tiroiditis autoinmune (tiroiditis de Hashimoto y enfermedad de Graves), lupus eritematoso sistémico, artritis reumatoide y síndrome de Sjögren primario.

Abstract MicroRNAs (miRNAs) are small non-coding RNAs of approximately 17-24 nucleotides in length, which complementarily and mainly bind in 3' UTR (untranslated region) regions of different messenger RNAs (mRNAs). Their general function is to negatively regulate gene expression at the posttranscriptional level, thus inhibiting translation. miRNA abnormal expression profiles of have been found in different human fluids, cells and tissues affected by different autoimmune diseases, and some of them have been proposed as potential biomarkers of diagnosis, prognosis, activity etc. in these pathologies. In addition, common variants of the human genome, called single-nucleotide polymorphisms (SNPs), located within miRNA genes, have been associated with susceptibility, severity and activity in these diseases. The purpose of this review is to describe miRNA biogenesis and function, as well as the expression profiles and SNPs in miRNA genes that are associated with different autoimmune diseases, including autoimmune thyroiditis (HashimotoMs thyroiditis and Gravess disease), systemic lupus erythematosus, rheumatoid arthritis and primary Sjögren's syndrome.

Leucemia linfoblástica aguda infantil: una aproximación genómica / Acute lymphoblastic leukemia: a genomic perspective

Resumen: En paralelo al proyecto de la secuenciación del genoma humano, se han desarrollado varias plataformas tecnológicas que están permitiendo ganar conocimiento sobre la estructura del genoma de las entidades humanas, así como evaluar su utilidad en el abordaje clínico del paciente. En la leucemia linfoblástica aguda (LLA), el cáncer infantil más común, las herramientas genómicas prometen ser útiles para detectar a los pacientes con alto riesgo de recaída, ya sea al diagnóstico o durante el tratamiento (enfermedad mínima residual), además de que permiten identificar los casos en riesgo de presentar reacciones adversas a los tratamientos antineoplásicos y ofrecer una medicina personalizada con esquemas terapéuticos diseñados a la medida del paciente. Un ejemplo claro de esto último es la identificación de polimorfismos de un solo nucleótido (SNPs) en el gen de la tiopurina metil transferasa (TPMT), donde la presencia de dos alelos nulos (homocigotos o heterocigotos compuestos) indica la necesidad de reducir la dosis de la mercaptopurina hasta en un 90% para evitar efectos tóxicos que pueden conducir a la muerte del paciente. En esta revisión se proporciona una visión global de la genómica de la LLA, describiendo algunas estrategias que contribuyen a la identificación de biomarcadores con potencial utilidad en la práctica clínica.

Abstract: In parallel to the human genome sequencing project, several technological platforms have been developed that let us gain insight into the genome structure of human entities, as well as evaluate their usefulness in the clinical approach of the patient. Thus, in acute lymphoblastic leukemia (ALL), the most common pediatric malignancy, genomic tools promise to be useful to detect patients at high risk of relapse, either at diagnosis or during treatment (minimal residual disease), and they also increase the possibility to identify cases at risk of adverse reactions to chemotherapy. Therefore, the physician could offer patient-tailored therapeutic schemes. A clear example of the useful genomic tools is the identification of single nucleotide polymorphisms (SNPs) in the thiopurine methyl transferase (TPMT) gene, where the presence of two null alleles (homozygous or compound heterozygous) indicates the need to reduce the dose of mercaptopurine by up to 90% to avoid toxic effects which could lead to the death of the patient. In this review, we provide an overview of the genomic perspective of ALL, describing some strategies that contribute to the identification of biomarkers with potential clinical application.

Genética y genómica de la hipertensión arterial: una actualización / Genetic and genomic studies in the hypertension: an actualization

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.

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.

Marcadores pro y antiinflamatorios en la enfermedad arterial coronaria y el síndrome isquémico coronario agudo / Pro-inflammatory and anti-inflammatory markers in coronary artery disease and acute ischemic coronary syndrome

Inflammation plays an important role in the development of atherosclerotic lesions, affecting several stages of the atheroma's development going from the initial leukocyte recruitment to the eventual rupture of the unstable atherosclerotic plaque. The inflammatory reactions within coronary atherosclerotic plaques influence the clinical outcome of acute coronary syndromes and coronary artery disease. Recent studies suggest that inflammation markers may reflect different aspects of the atherothrombotic process in relation to the stages of acute coronary syndrome. These markers play an important role in the risk of developing coronary artery disease, and may correlate with its severity. Some cytokines, acute phase proteins, acute phase reactants proteins, and adhesion molecules released from the inflammatory cells may reflect the inflammatory process in atherosclerotic plaques. However, it remains to be determined whether these pro- and anti-inflammation markers may confer risk or protection for cardiovascular disease, or simply reflect the underlying disease process. The analysis of the markers may be useful for the development of new strategies for coronary disease prevention and treatment. Therefore, we need a well-designed evaluation of these markers before their use in the clinical practice.