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Interpretation of variants of unknown significance (VUS) in genetic tests is complicated in ethnically diverse populations, given the lack of information regarding the common spectrum of genetic variation in clinically relevant genes. Public availability of data obtained from high-throughput genotyping and/or exome massive parallel sequencing (MPS)-based projects from several thousands of outbred samples might become useful tools to evaluate the pathogenicity of a VUS, based on its frequency in different populations. In the case of the Mexican and other Latino populations, several thousands of samples have been genotyped or sequenced during the last few years as part of different efforts to identify common variants associated to common diseases. In this report, we analyzed Mexican population data from a sample of 3985 outbred individuals, and additional 66 hereditary breast cancer patients were analyzed in order to better define the spectrum of common genomic variation of the BRCA1 and BRCA2 genes. Our analyses identified the most common genetic variants in these clinically relevant genes as well as the presence and frequency of specific pathogenic mutations present in the Mexican population. Analysis of the 3985 population samples by MPS identified three pathogenic mutations in BRCA1, only one population sample showed a BRCA1 exon 16-17 deletion by MLPA. This resulted in a basal prevalence of deleterious mutations of 0.10% (1:996) for BRCA1 and 11 pathogenic mutations in BRCA2, resulting in a basal prevalence of deleterious mutations of 0.276% (1:362) for BRCA2, combined of 0.376% (1:265). Separate analysis of the breast cancer patients identified the presence of pathogenic mutations in 18% (12 pathogenic mutations in 66 patients) of the samples by MPS and 13 additional alterations by MLPA. These results will support a better interpretation of clinical studies focused on the detection of BRCA mutations in Mexican and Latino populations and will help to define the general prevalence of deleterious mutations within these populations.

Non-Hodgkin lymphoma comprises a heterogeneous group of haematological malignancies, classified according to their clinic, anatomic-pathological features and, lately, to their molecular biomarkers. Despite the therapeutic advances, nearly half of the patients will die because of this disease. The new diagnostic tools have been the cornerstone to design recent therapy targets, which must be included in the current treatment guidelines of this sort of neoplasms by means of clinical trials and evidence-based medicine. In the face of poor diagnoses devices in most of the Mexican hospitals, we recommend the present diagnose stratification, and treatment guidelines for non-Hodgkin lymphoma, based on evidence. They include the latest and most innovative therapeutic approaches, as well as specific recommendations for hospitals with limited framework and therapy resources.

By using novel molecular markers, it is possible to gain information on both the classification and the pathophysiology of the chronic myeloproliferative neoplasia (MPN). In a group of 36 Mexican mestizo patients with MPN, we studied five molecular markers: The BCR/ABL1 fusion gene, the JAK2 V617F mutation, the JAK2 exon 12 mutations, the MPL W515L mutation and the MPL W515K mutation; 17 patients with essential thrombocythemia (ET), eight with polycythemia vera (PV), four with primary mielofibrosis (MF), five with undifferentiated MPN, one with primary erythrocytosis and one with familial thrombocytosis. Patients with the BCR/ABL1 fusion gene were excluded. Twelve individuals with the JAK2 V617F mutation were found; 11 of them had been clinically classified as PV and one had been classified as MF. One patient with the MPL W515L was identified with a clinical picture of ET. No individuals with either the MPL W515K mutation or the JAK2 exon 12 mutations were identified. Of the 17 individuals with ET, six (35%) had the JAK2 V617F mutation and one (6%) was found to have the MPL W515L mutation. Of the eight individuals with PV, five displayed the JAK2 V617F mutation, whereas of the four patients with MF, one had the JAK2 V617F mutation. The most consistent relationship was that between PV and the JAK2 V617F mutation (p=0.08). In the diagnosis and classification of the MPN, in addition to the newly identified molecular markers, clinical and laboratory data are still very important.

Objectives: To document the clinical and epidemiological characteristics present in dengue patients served by a hospital in Culiacan, Sinaloa, Mexico., Methods: A cross-sectional, observational, and analytical study was carried out at the Hospital General Dr. Bernardo J. Gastélum de Culiacan from 1 October to 2 December 2003. Associations between the independent variables (the patients' clinical and epidemiological characteristics) and the dependent variable (confirmed hemorrhagic dengue) were determined through simple regression analysis. The variables that were significantly associated (P < 0.05) were submitted to multifactorial logistic regression analysis., Results: Of the only 241 cases that met the study's inclusion criteria (207 dengue and 34 hemorrhagic dengue), the mean age was 34.7 +/- 15.1 years. According to the results of the multifactorial analysis (adjusted by age, sex, and the presence of dengue cases at the geographic location), the variables predictive of major complications of the disease were: the presence of ascites (odds ration [OR] = 22.12; 95% confidence interval [95%CI]: 5.00-97.87), gingivorrhagia (OR = 7.35; 95%CI: 2.11-25.61), hematemesis (OR = 7.40; 95%CI: 1.04-52.42), thrombocytopenia (platelets from 40,001/mm(3)-60,000/mm(3)) (OR = 5.43; 95%CI: 1.58-18.72), conjunctival hyperemia (OR = 4.27; 95%CI: 1.37-13.28), persistent vomiting (OR = 3.04; 95%CI: 1.05-8.80), and the absence of nasal congestion (OR = 0.015; 95%CI: 0.0004-0.473)., Conclusions: The presence of ascites, gingivorrhagia, hematemesis, thrombocytopenia (with platelet values from 40,001/mm(3)-60,000/mm(3)), and persistent vomiting were confirmed as warning signs of an imminent dengue attack. Platelet counts of > 100,000/mm(3) were confirmed in cases with acute clinical symptoms (capillary leak) that were not classified as hemorrhagic dengue due to falling short of the criteria established by WHO.