Unraveling Signatures of Local Adaptation among Indigenous Groups from Mexico.

Few studies have addressed how selective pressures have shaped the genetic structure of the current Native American populations, and they have mostly limited their inferences to admixed Latin American populations. Here, we searched for local adaptation signals, based on integrated haplotype scores and population branch statistics, in 325 Mexican Indigenous individuals with at least 99% Native American ancestry from five previously defined geographical regions. Although each region exhibited its own local adaptation profile, only PPARG and AJAP1, both negative regulators of the Wnt/ß catenin signaling pathway, showed significant adaptation signals in all the tested regions. Several signals were found, mainly in the genes related to the metabolic processes and immune response. A pathway enrichment analysis revealed the overrepresentation of selected genes related to several biological phenotypes/conditions, such as the immune response and metabolic pathways, in agreement with previous studies, suggesting that immunological and metabolic pressures are major drivers of human adaptation. Genes related to the gut microbiome measurements were overrepresented in all the regions, highlighting the importance of studying how humans have coevolved with the microbial communities that colonize them. Our results provide a further explanation of the human evolutionary history in response to environmental pressures in this region.

RECK Variants are Associated with Clinicopathological Features and Decreased Susceptibility in Mexican Patients with Colorectal Cancer.

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of death worldwide. Down-regulation of the cysteine-rich reversion-inducing protein with Kazal motifs (RECK) has been confirmed in numerous human cancers and is clinically associated with metastasis. This study aims to explore, for the first time, the possible association of the RECK variants rs11788747 and rs10972727 with CRC susceptibility and clinicopathological features. DNA from 130 CRC patients and 130 healthy blood donors was analyzed. Identification of genetic variants was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. Association was calculated using the odds ratio (OR) test and P values were adjusted using the Bonferroni test. Individuals carrying the G/G genotype for the rs11788747 variant showed a lower risk of colorectal cancer (OR 0.33; 95% CI 0.16-0.70; P = 0.006). Patients older than 50 years who carry the G/G genotype have a lower risk of CRC (OR 0.26; 95% CI 0.09-0.73; P = 0.019) and of developing advanced tumor-nodule-metastasis (TNM) stages (OR 0.23; 95% CI 0.09-0.54; P = 0.001). Individuals carrying the A/A genotype of the rs10972727 variant also showed decreased risk of CRC (OR 0.38; 95% CI 0.19-0.77; P = 0.011), and were associated with age (over 50 years), sex, advanced TNM stages, and tumor location in the colon. Our results suggest that the RECK variants studied here (rs11788747 and rs10972727) are associated with decreased CRC risk, TNM stages and tumor location.

MKK4 variants rs3826392 and rs3809728 are associated with susceptibility and clinicopathological features in colorectal cancer patients.

OBJECTIVES: The mitogen-activated protein kinase kinase 4 (MKK4) plays a key role in several processes like inflammation, apoptosis, and tumorigenesis. Several authors have proposed that genetic variations in these genes may alter their expression with subsequent cancer risk. This study aimed to examine the possible association of MKK4 rs3826392 and rs3809728 variants in Mexican patients with colorectal cancer (CRC). These variants were also compared with clinical features as sex, age, TNM stage, and tumor location. MATERIALS AND METHODS: The study included genomic DNA from 218 control subjects and 250 patients. Genotyping of the MKK4 variants was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) procedure. RESULTS: Individuals with A/T and T/T genotypes for the rs3809728 (-1044 A>T) variant showed a significantly increased risk for CRC (P=0.012 and 0.007, respectively); while individuals with the G/G genotype for the rs3826392 (-1304 T>G) variant showed a decreased risk for CRC (P=0.012). Genotypes of the MKK4 rs3809728 variant were also significantly related to colon localization and advanced TNM stage in CRC patients. T-T haplotype (rs3826392 and rs3809728) of the MKK4 gene was associated with risk in patients with CRC. CONCLUSION: The rs3826392 variant in the MKK4 gene could be a cancer protective factor, while the rs3809728 variant could be a risk factor. These variants play a significant role in CRC risk.

The genomic landscape of Mexican Indigenous populations brings insights into the peopling of the Americas.

The genetic makeup of Indigenous populations inhabiting Mexico has been strongly influenced by geography and demographic history. Here, we perform a genome-wide analysis of 716 newly genotyped individuals from 60 of the 68 recognized ethnic groups in Mexico. We show that the genetic structure of these populations is strongly influenced by geography, and our demographic reconstructions suggest a decline in the population size of all tested populations in the last 15-30 generations. We find evidence that Aridoamerican and Mesoamerican populations diverged roughly 4-9.9 ka, around the time when sedentary farming started in Mesoamerica. Comparisons with ancient genomes indicate that the Upward Sun River 1 (USR1) individual is an outgroup to Mexican/South American Indigenous populations, whereas Anzick-1 was more closely related to Mesoamerican/South American populations than to those from Aridoamerica, showing an even more complex history of divergence than recognized so far.

CD44 Genotypes Are Associated with Susceptibility and Tumor Characteristics in Colorectal Cancer Patients.

Colorectal cancer is the third cause of cancer and the second leading cause of death worldwide. The CD44 gene plays a key role in malignant processes, including growth, survival, epithelial to mesenchymal transition and metastasis. It is also known that some variants as rs187116 (c.67+4883G>A) and rs7116432 (c.2024+779A>G) can modulate the function of the CD44 gene and malignant transformation in several neoplasms. This study aims to explore, for the first time, the association of the CD44 rs187116 and rs7116432 variants in patients with colorectal cancer. Genomic DNA from 250 patients and 250 healthy blood donors were analyzed. The identification of variants was made by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. Association was calculated by the odds ratio (OR) test and multivariate analysis. Individuals carrying the G/A and A/A genotypes for the rs187116 polymorphism showed an increased risk for colorectal cancer (OR = 3.11, 95% CI: 1.87-5.16, P = 0.001 and OR = 3.59, 95% CI: 2.06-6.25, P = 0.001, respectively). After adjusting for age and gender, these same genotypes and the G/G genotype of the rs7116432 polymorphism were associated with TNM stage and tumor location in the colon. Moreover, the A-G (rs187116 and rs7116432) haplotype was associated with increased risk; while, the haplotype G-A (rs187116 and rs7116432) was related with decreased risk. In conclusion, our results suggest that the here analyzed CD44 variants are involved with risk, TNM stage and tumor location in colorectal cancer.

Genetic Polymorphisms in APC, DVL2, and AXIN1 Are Associated with Susceptibility, Advanced TNM Stage or Tumor Location in Colorectal Cancer.

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of death worldwide. The named "destruction complex" has a critical function in the Wnt/ß-catenin pathway regulating the level of ß-catenin in the cytoplasm and nucleus. Alterations in this complex lead to the cellular accumulation of ß-catenin, which participates in the development and progression of CRC. This study aims to determine the contribution of polymorphisms in the genes of the ß-catenin destruction complex to develop CRC, specifically adenomatous polyposis coli (APC) (rs11954856 G>T and rs459552 A>T), axis inhibition protein 1 (AXIN1) (rs9921222 C>T and rs1805105 C>T), AXIN2 (rs7224837 A>G), and dishevelled 2 (DVL2) (2074222 G>A and rs222836 C>T). Genomic DNA from 180 sporadic colorectal cancer patients and 150 healthy blood donors were analyzed. The identification of polymorphisms was made by polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) methodology. Association was calculated by the odds ratio (OR) test. Increased susceptibility to CRC was associated with the polymorphic variants rs11954856 (APC), rs222836 (DVL2), and rs9921222 (AXIN1). Decreased susceptibility was associated with the polymorphisms rs459552 (APC) and 2074222 (DVL2). Association was also observed with advanced Tumor-Node-Metastasis (TNM) stages and tumor location. The haplotypes G-T in APC (rs11954856-rs459552) and A-C in DVL2 (rs2074222-rs222836) were associated with decreased risk of CRC, while the G-T haplotype in the DVL2 gene was associated with increased CRC risk. In conclusion, our results suggest that variants in the destruction complex genes may be involved in the promotion or prevention of colorectal cancer.

GSK3ß Polymorphisms Are Associated with Tumor Site and TNM Stage in Colorectal Cancer.

BACKGROUND: Mutations and polymorphisms of the GSK3ß gene have been associated with several diseases including Alzheimer disease, diabetes and cancer; however, to date, no variants of this gene have been associated with colorectal cancer (CRC). This study aims to explore, for the first time, the association of the GSK3ß rs334558 and rs6438552 polymorphisms with CRC. METHODS: Genomic DNA from 330 CRC patients and healthy blood donors were analyzed. Identification of polymorphisms was made by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. Association was calculated by the odds ratio (OR) test. RESULTS: Patients carrying the C/T genotype for the rs334558 (T>C) polymorphism showed an increased risk for CRC (OR = 1.71, 95% CI: 1.05-2.79, P = 0.039); this association was also observed for TNM stage and tumor location. For the rs6438552 (T>C) polymorphism, the OR analysis showed that patients carrying C/T and C/C genotypes have a decreased risk for CRC (OR = 0.44, 95% CI: 0.27-0.70, P = 0.001 and OR = 0.24, 95% CI: 0.10-0.64, P = 0.001, respectively); this decreased risk was also evident in the stratified analysis by TNM stage and tumor location. Haplotype analysis of these 2 loci of GSK3ß (rs334558 and rs6438552) showed differential distribution. The T-T and C-C haplotype was associated with a decreased risk of CRC, while the T-C haplotype was associated with an increased risk of CRC. CONCLUSION: Our results denote that GSK3ß gene polymorphisms play a significant role in promoting or preventing CRC. Additionally, variations in this gene are associated with the tumor site and the tumor-node-metastasis (TNM) stage in these patients.

Interleukin-1 Alpha Polymorphisms Are Associated With Body Mass Index in Male But Not in Female Adolescents.

BACKGROUND: The Interleukin (IL)-1 family of cytokines plays a key role in the inflammatory response. Genes coding for IL-1α, IL-1ß, and IL-1Ra are located together as a block gene known as the IL-1 cluster. This genomic region shows wide nucleotide variability, and some polymorphisms have been widely studied and associated with features related to the metabolic syndrome. METHODS: Eight polymorphisms within three genes of the IL-1 cluster, including IL1A (rs3783553, rs17561, and rs1800587), IL1B (rs1143634, rs1143627, and rs16944) and IL1RN (rs419598 and rs2234663) were genotyped in 460 Mexican adolescents. Genotype and haplotype frequencies are reported, as well as the linkage disequilibrium analysis. Genetic associations with some anthropometric and metabolic traits were evaluated. RESULTS: Allele frequencies were similar to those found in other populations, and genotype proportions were according to the Hardy-Weinberg equilibrium. Seven haplotypes were observed at frequencies ≥5%. Of the entire cluster, only the rs17561-rs1800587 and rs1143627-rs16944 pairs showed highest and significant linkage disequilibrium values. An haplotype of IL1A, rs17561T-rs1800587T, was significantly associated with increase in body mass index in males (p <0.008), whereas IL1B and IL1RN variants showed associations with insulin, and hs-CRP (p <0.05). CONCLUSIONS: Some MetS parameters seem to be influenced by variations in the IL-1 gene cluster in Mexican adolescents. These variations may confer risk for metabolic alterations from early ages, and and these risks may be different when variables such as sex are considered. Strategies leading to generate protective behaviors could be designed to take into account specific variations in the IL-1 gene cluster and biological conditions such as sex.

Insulin glargine affects the expression of Igf-1r, Insr, and Igf-1 genes in colon and liver of diabetic rats.

OBJECTIVES: The mitogenic effect of the analogous insulin glargine is currently under debate since several clinical studies have raised the possibility that insulin glargine treatment has a carcinogenic potential in different tissues. This study aimed to evaluate the Igf-1r, Insr, and Igf-1 gene expression in colon and liver of streptozotocin-induced diabetic rats in response to insulin glargine, neutral protamine Hagedorn (NPH) insulin, and metformin treatments. MATERIALS AND METHODS: Male Wistar rats were induced during one week with streptozotocin to develop Type 2 Diabetes (T2D) and then randomly distributed into four groups. T2D rats included in the first group received insulin glargine, the second group received NPH insulin, the third group received metformin; finally, untreated T2D rats were included as the control group. All groups were treated for seven days; after the treatment, tissue samples of liver and colon were obtained. Quantitative PCR (qPCR) was performed to analyze the Igf-1r, Insr and Igf-1 gene expression in each tissue sample. RESULTS: The liver tissue showed overexpression of the Insr and Igf-1r genes (P>0.001) in rats treated with insulin glargine in comparison with the control group. Similar results were observed for the Insr gene (P>0.011) in colonic tissue of rats treated with insulin glargine. CONCLUSION: These observations demonstrate that insulin glargine promote an excess of insulin and IGF-1 receptors in STZ-induced diabetic rats, which could overstimulate the mitogenic signaling pathways.

Association analysis of calpain 10 gene variants/haplotypes with gestational diabetes mellitus among Mexican women.

Gestational diabetes mellitus (GDM) is a metabolically complex disease with major genetic determinants. GDM has been associated with insulin resistance and dysfunction of pancreatic beta cells, so the GDM candidate genes are those that encode proteins modulating the function and secretion of insulin, such as that for calpain 10 (CAPN10). This study aimed to assess whether single nucleotide polymorphism (SNP)-43, SNP-44, SNP-63, and the indel-19 variant, and specific haplotypes of the CAPN10 gene were associated with gestational diabetes mellitus. We studied 116 patients with gestational diabetes mellitus and 83 women with normal glucose tolerance. Measurements of anthropometric and biochemical parameters were performed. SNP-43, SNP-44, and SNP-63 were identified by polymerase chain reaction (PCR)-restriction fragment length polymorphisms, while the indel-19 variant was detected by TaqMan qPCR assays.  The allele, genotype, and haplotype frequencies of the four variants did not differ significantly between women with gestational diabetes mellitus and controls. However, in women with gestational diabetes mellitus, glucose levels were significantly higher bearing the 3R/3R genotype than in carriers of the 3R/2R genotype of the indel-19 variant (p = 0.006). In conclusion, the 3R/3R genotype of the indel-19 variant of the CAPN-10 gene influenced increased glucose levels in these Mexican women with gestational diabetes mellitus.

Gene expression profiling demonstrates WNT/ß-catenin pathway genes alteration in Mexican patients with colorectal cancer and diabetes mellitus.

PURPOSE: Several studies have shown a strong association between diabetes mellitus (DM) and increased risk of colorectal cancer (CRC). The fundamental mechanisms that support this association are not entirely understood; however, it is believed that hyperinsulinemia and hyperglycemia may be involved. Some proposed mechanisms include upregulation of mitogenic signaling pathways like MAPK, PI3K, mTOR, and WNT, which are involved in cell proliferation, growth, and cancer cell survival. The purpose of this study was to evaluate the gene expression profile and identify differently expressed genes involved in mitogenic pathways in CRC patients with and without DM. METHODS: In this study, microarray analysis of gene expression followed by quantitative PCR (qPCR) was performed in cancer tissue from CRC patients with and without DM to identify the gene expression profiles and validate the differently expressed genes. RESULTS: Among the study groups, some differently expressed genes were identified. However, when bioinformatics clustering tools were used, a significant modulation of genes involved in the WNT pathway was evident. Therefore, we focused on genes participating in this pathway, such as WNT3A, LRP6, TCF7L2, and FRA-1. Validation of the expression levels of those genes by qPCR showed that CRC patients without type 2 diabetes mellitus (T2DM) expressed significantly more WNT3Ay LRP6, but less TCF7L2 and FRA-1 compared to controls, while in CRC patients with DM the expression levels of WNT3A, LRP6, TCF7L2, and FRA-1 were significantly higher compared to controls. CONCLUSIONS: Our results suggest that WNT/ß-catenin pathway is upregulated in patients with CRC and DM, demonstrating its importance and involvement in both pathologies.

Analysis of cytokine gene polymorphisms in Mestizo and native populations from Mexico.

OBJECTIVES: To determine whether the well-known genetic structure of the Mexican population observed with other multiallelic markers can be detected by analyzing functional polymorphisms of cytokine and other inflammatory-response-related genes. METHODS: A total of 834 Mestizo individuals from five Mexican cities and 92 Lacandonians - an Amerindian group from southeastern Mexico - were genotyped for 14 polymorphisms in the CRP, IL10, IL6, TGFB1, TNFA, LTA, ICAM1 IFNG, and IL1RN genes. Allele and haplotype frequencies were used for genetic structure analysis using F-statistics pairwise distances and multidimensional scaling plot. Ancestry analysis was performed, as well. RESULTS: Significant interpopulational differences at the allele and haplotype frequency level were observed, mainly between Northern (Guadalajara, Monterrey, and Culiacan) and Southern (Tierra Blanca and Puebla) Mexican populations. Also, low but significant substructure was detected between some populations from these two broad regions. Interestingly, both Lacandonian populations were highly differentiated from each other and with respect to Mestizos. Consistent with previous data, Amerindian ancestry in the Southern Mexican groups was higher compared to Northern ones. CONCLUSIONS: The Mexican population exhibits regional differences in functional polymorphisms of inflammatory-response genes, as observed for other genetic markers. This information constitutes a reference for epidemiological studies that include these genetic markers to assess the susceptibility of the Mexican population to several immune-response-related diseases, such as diabetes, obesity, and renal disease, which have been shown to be common in the Mexican population but with prevalence differences within this country.

CYP2C9 and CYP2C19 Allele and Haplotype Distributions in Four Mestizo Populations from Western Mexico: An Interethnic Comparative Study.

AIMS: Polymorphisms in the CYP2C9 and CYP2C19 genes confer potential risk for specific adverse drug reactions and therapeutic effect failure. Their frequencies differ among ethnic groups. This study was aimed to describe the distribution of CYP2C9 and CYP2C19 alleles and haplotypes in four Mestizo populations from Western Mexico and their comparison with the reported data from other ethnic groups. METHODS: The CYP2C alleles (CYP2C9*2, CYP2C9*3, CYP2C19*2, and CYP2C19*3) were genotyped using polymerase chain reaction-restriction fragment length polymorphisms analyses using DNA samples from 477 healthy Mestizo individuals of Colima (n = 100), Jalisco (n = 147), Michoacán (n = 117), and Nayarit (n = 113). RESULTS: Frequencies ranged from 2.2-3.0% and 4.8-8.9% for CYP2C9*3 and CYP2C9*2 alleles, respectively, and 5.4-12.0% for CYP2C19*2, whereas the CYP2C19*3 allele was not found. Haplotype GACA, which harbors the loss-of-function allele CYP2C19*2, was the second most frequent (8.7%). Genetic heterogeneity between the Western Mexican populations studied here and the global population was evident (p < 0.05), except for most American populations and other Mexican Mestizo populations. CONCLUSION: Our findings increase the evidence for genetic variability at relevant pharmacogenetic loci and could be useful in association studies involving drugs that are substrates for CYP2C enzymes in the Western Mexican population.

AXIN2 Polymorphisms and Their Association with Colorectal Cancer in Mexican Patients.

AIM: The aim of this study was to investigate the association of the rs2240308 and rs1133683 polymorphisms in the AXIN2 gene with colorectal cancer (CRC) in Mexican patients. MATERIALS AND METHODS: Genomic DNAs from 201 CRC patients and 100 healthy blood donors were analyzed for AXIN2 gene polymorphisms by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. Statistical associations were calculated using the odds ratio (OR) test. RESULTS: The genotype distribution of the rs1133683 polymorphism C > T showed a statistical difference between the two study groups (p = 0.0019). Moreover, OR analyses demonstrated that individuals with either the C/T or T/T genotype have a decreased risk for CRC compared with individuals with the C/C genotype (OR = 0.47, 95% confidence interval [CI] = 0.25-0.86, p = 0.0134 and OR = 0.24, 95% CI = 0.10-0.57, p = 0.005, respectively). This association was also evident in a stratified analysis based on tumor-node-metastasis (TNM) stage. For the rs2240308 polymorphism C > T, the OR analysis showed a significantly increased risk for carriers of the T/T genotype (OR = 2.64, 95% CI = 1.12-6.24, p = 0.0236) and this association was also evident in the stratified analysis by TNM stage. CONCLUSION: Our results indicate the possibility that variations in the AXIN2 gene may play a significant role in promoting or preventing CRC development.

[Association analysis of SNP-63 and indel-19 variant in the calpain-10 gene with polycystic ovary syndrome in women of reproductive age]. / Análisis de asociación del SNP-63 y la variante indel-19 del gen de calpaína-10 con síndrome de ovario poliquístico en mujeres en edad reproductiva.

BACKGROUND: Polycystic ovary syndrome is a complex and heterogeneous disease involving both reproductive and metabolic problems. It has been suggested a genetic predisposition in the etiology of this syndrome. The identification of calpain-10 gene (CAPN10) as the first candidate gene for type 2 diabetes mellitus, has focused the interest in investigating their possible relation with the polycystic ovary syndrome, because this syndrome is associated with hyperinsulinemia and insulin resistance, two metabolic abnormalities associated with type 2 diabetes mellitus. OBJECTIVE: To investigate if there is association between the SNP-63 and the variant indel-19 of the CAPN10 gene and polycystic ovary syndrome in women of reproductive age. MATERIAL AND METHODS: This study included 101 women (55 with polycystic ovary syndrome and 46 without polycystic ovary syndrome). The genetic variant indel-19 was identified by electrophoresis of the amplified fragments by PCR, and the SNP-63 by PCR-RFLP. RESULTS: The allele and genotype frequencies of the two variants do not differ significatly between women with polycystic ovary syndrome and control women group. The haplotype 21 (defined by the insertion allele of indel-19 variant and C allele of SNP-63) was found with higher frequency in both study groups, being more frequent in the polycystic ovary syndrome patients group, however, this difference was not statistically significant (p = 0.8353). CONCLUSIONS: The results suggest that SNP-63 and indel-19 variant of the CAPN10 gene do not represent a risk factor for polycystic ovary syndrome in our patients group.

Glutathione peroxidase 3 serum levels and GPX3 gene polymorphisms in subjects with metabolic syndrome.

BACKGROUND AND AIMS: Glutathione peroxidase 3 (GPx3) plays a main role in removing hydro- and lipoperoxides from the body. Changes in concentration and several single-nucleotide polymorphisms (SNP) at the GPX3 gene have been associated with vascular diseases, but the relationship of GPx3 with metabolic syndrome (MetS) remains unexplored. We undertook this study to determine the association of GPx3 serum levels and several GPX3 SNPs with the presence of MetS in Mexican subjects. METHODS: Clinical, biochemical, and anthropometric evaluation were conducted in 426 subjects assigned to three groups: control (n = 42); risk group (RG, n = 200), and MetS group (n = 184). Insulin sensitivity (IS) and cardiovascular risk were determined by the QUICKI and TG/HDL-C index, respectively. Serum GPx3 was determined by enzyme immunoassay and polymorphisms within GPX3 gene were identified by nucleotide sequencing. RESULTS: MetS group showed low IS and increased cardiovascular risk with respect to controls as well as higher GPx3 serum levels (172.9 ± 32.2 vs. 145.6 ± 24.8 ng/dL; p <0.05). Only three of the ten GPX3 SNPs screened were polymorphic with two haplotypes observed (CCT and TTA-rs8177404, rs8177406, and rs8177409), indicating tight linkage disequilibrium in this genetic region. No differences for either genotype or allele frequencies among groups were observed, but rs8177409 (allele T) was associated with cardiovascular risk (odds ratio [OR], 4.5; p = 0.0125). CONCLUSION: This study shows that serum levels of GPx3 are increased in subjects with MetS and that rs8177409 SNP was associated with cardiovascular risk in a Mexican population.

Adiposidade corporal, mas não resistência insulínica, associa-se ao polimorfismo -675 4G/5G no gene PAI-1 em uma amostra de crianças mexicanas / Body adiposity but not insulin resistance is associated with -675 4G/5G polymorphism in the PAI-1 gene in a sample of Mexican children

OBJETIVO: Elaboramos este estudo para avaliar se o polimorfismo -675 4G/5G no gene inibidor 1 do ativador do plasminogênio se associa à obesidade e à resistência insulínica em crianças mexicanas. MÉTODOS: Foi realizado um estudo transversal em 174 crianças, 89 delas com peso normal e 85 obesas, variando sua idade de 6 a 13 anos. Todas as crianças eram do estado de Guerrero e foram recrutadas de três escolas primárias na cidade de Chilpancingo, México. Os níveis de insulina foram determinados por prova imunoenzimática. Foi usado o modelo de avaliação da homeostase para determinar resistência insulínica. O polimorfismo -675 4G/5G no gene PAI-1 foi analisado pelo método reação de polimerase em cadeia-polimorfismo no comprimento dos fragmentos de restrição. RESULTADOS: A prevalência de resistência insulínica no grupo obeso foi mais alta (49,41%) do que no grupo com peso normal (16,85%). O polimorfismo 4G/5G do PAI-1 foi encontrado em equilíbrio de Hardy Weinberg. O genótipo 4G/5G contribuiu para um aumento significativo da relação cintura-quadril (β = 0,02, p = 0,006), da circunferência da cintura (β = 4,42, p = 0,009) e da espessura da prega subescapular (β = 1,79, p = 0,04), mas não se relacionou com a resistência insulínica. CONCLUSÃO: O genótipo -675 4G/5G do gene PAI-1 se associou a aumento da adiposidade corporal em crianças mexicanas.

OBJECTIVE: To assess whether the -675 4G/5G polymorphism in the plasminogen activator inhibitor-1 gene is associated with obesity and insulin resistance in Mexican children. METHODS: A cross-sectional study was performed in 174 children, 89 with normal-weight and 85 with obesity, aged from 6 to 13 years. All children were from state of Guerrero, and recruited from three primary schools in the city of Chilpancingo, Mexico. Insulin levels were determined by immunoenzymatic assay. The homeostasis model assessment was used to determine insulin resistance. The -675 4G/5G polymorphism in PAI-1 gene was analyzed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The prevalence of insulin resistance in the obese group was higher (49.41%) than in the normal-weight group (16.85%). The 4G/5G PAI-1 polymorphism was found in Hardy Weinberg equilibrium. The 4G/5G genotype contributed to a significant increase in waist-hip ratio (β = 0.02, p = 0.006), waist circumference (β = 4.42, p = 0.009), and subscapular skinfold thickness (β = 1.79, p = 0.04); however, it was not related with insulin resistance. CONCLUSION: The -675 4G/5G genotype of PAI-1 gene was associated with increase of body adiposity in Mexican children.

Low prevalence of interleukin-6 haplotypes associated with a decreased risk of type 2 diabetes in Mexican subjects with a family history of type 2 diabetes.

BACKGROUND AND AIMS: There is evidence that family history of type 2 diabetes (FHT2D) and single nucleotide polymorphisms (SNP) on the IL-6 gene promoter region are separately associated with the risk of developing type 2 diabetes. However the relationship between adult Mexican subjects with FHT2D and genotypes/haplotypes for IL-6 gene has not been explored. The aim of the present work was to study the prevalence of IL-6 -598G>A-572G>C-174G>C haplotypes among subjects with FHT2D and to determine whether their presence influences the relationship between FHT2D and risk factors for diabetes. METHODS: Two hundred fifty eight nondiabetic subjects participated in this study; 153 with and 105 without FHT2D. Polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) was used for genotyping. Logistic regression analysis was employed to assess the impact of IL-6 haplotypes on FHT2D per se and hyperinsulinemia and insulin resistance as risk factors for diabetes. RESULTS: Subjects with FHT2D showed a higher prevalence of hyperinsulinemia and insulin resistance (IR) than those without FHT2D (14.4 vs. 5.7%, p = 0.029, and 14.2 vs. 7.0% p = 0.050, respectively). Lower prevalence of -598 -572-174 (AGC)-haplotype (19%) in subjects with FHT2D was observed as well as a lower prevalence of hyperinsulinemia and IR among AGC haplotype carriers (12 and 14%, respectively). The relationship between FHT2D and IR was modified by the presence of AGC haplotype (from OR, 2.70; 95% CI, 0.99-7.36; p = 0.050 OR, 30.08; 95% CI, 0.58-1,568.06; p = 0.092). CONCLUSIONS: IL-6 -598/-572/-174 (AGC) haplotype has a low prevalence among first-degree relatives of subjects with type 2 diabetes. Our results suggest that this haplotype is associated with decreased risk of type 2 diabetes in Mexican subjects with FHT2D.

Body adiposity but not insulin resistance is associated with -675 4G/5G polymorphism in the PAI-1 gene in a sample of Mexican children.

OBJECTIVE: To assess whether the -675 4G/5G polymorphism in the plasminogen activator inhibitor-1 gene is associated with obesity and insulin resistance in Mexican children. METHODS: A cross-sectional study was performed in 174 children, 89 with normal-weight and 85 with obesity, aged from 6 to 13 years. All children were from state of Guerrero, and recruited from three primary schools in the city of Chilpancingo, state of Guerrero, Mexico. Insulin levels were determined by immunoenzymatic assay. The homeostasis model assessment was used to determine insulin resistance. The -675 4G/5G polymorphism in PAI-1 gene was analyzed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The prevalence of insulin resistance in the obese group was higher (49.41%) than in the normal-weight group (16.85%). The 4G/5G PAI-1 polymorphism was found in Hardy Weinberg equilibrium. The 4G/5G genotype contributed to a significant increase in waist-hip ratio (ß=0.02, p=0.006), waist circumference (ß=4.42, p=0.009), and subscapular skinfold thickness (ß=1.79, p=0.04); however, it was not related with insulin resistance. CONCLUSION: The -675 4G/5G genotype of PAI-1 gene was associated with increase of body adiposity in Mexican children.

[Pharmacogenetics and antiepileptic drug metabolism: implication of genetic variants in cytochromes P450]. / Farmacogenetica y metabolismo de farmacos antiepilepticos: implicacion de variantes geneticas en citocromos P450.

INTRODUCTION: Antiepileptic drugs (AEDs) are used for the seizures control in patients with epilepsy, however 20-30% of epileptic patients are drug resistant. Several factors contributing to the variability of the AEDs response, and this variability can be partially attributed to the presence of sequence variations (polymorphisms) in genes encoding enzymes involved in the AEDs metabolism. AIM: To describe the polymorphisms in genes that encoding for proteins involved in the metabolism of some of the major AEDs, focusing on enzymes cytochrome P450 (CYP450). DEVELOPMENT: There are some polymorphisms in genes encoding proteins involved in drug metabolism, particularly enzymes of superfamily CYP450, that are already considered of clinical utility in the therapeutic management. These genetic variants contribute to the variability of the activity of metabolizing enzymes, which in turn influencing the poor or inadequate therapeutic response, as well as in the occurrence of adverse effects. CONCLUSIONS: The identification of interindividual variability in the response to AEDs may allow the personalized treatment with the aim of maximize the efficiency and minimize risk, regardless of the clinical variability and adverse effects could be manifest in a minority of the patients.

TITLE: Farmacogenetica y metabolismo de farmacos antiepilepticos: implicacion de variantes geneticas en citocromos P450.Introduccion. Los farmacos antiepilepticos (FAE) son la base para el control de las crisis en pacientes con epilepsia; sin embargo, se conoce que el 20-30% de los pacientes son farmacorresistentes. Son diversos los factores que contribuyen a la variabilidad de la respuesta a los FAE, y esta variabilidad puede atribuirse, al menos en parte, a la presencia de polimorfismos (variaciones de la secuencia) en genes que codifican para enzimas involucradas en el metabolismo de los FAE. Objetivo. Describir las variaciones de la secuencia en genes que codifican para proteinas implicadas en el metabolismo de algunos de los principales FAE, con enfasis en las enzimas citocromo P450 (CYP450). Desarrollo. Existen algunos polimorfismos en genes que codifican para proteinas involucradas en el metabolismo de farmacos, particularmente enzimas de la superfamilia CYP450, que se consideran ya de utilidad clinica en el manejo terapeutico. La presencia de estas variantes geneticas contribuye a la variabilidad de la actividad de enzimas metabolizadoras, lo que, a su vez, influye en la pobre o inadecuada respuesta terapeutica, e incluso en la aparicion de efectos adversos. Conclusiones. La identificacion de la variabilidad interindividual en la respuesta a los diversos FAE puede permitir la individualizacion del tratamiento con la intencion de maximizar su eficacia y minimizar el riesgo, independientemente de que la variabilidad clinica y los efectos adversos se presenten en una minoria de pacientes.