Assessment of genotyping markers in the molecular characterization of a population of clinical isolates of Fusarium in Colombia / Evaluación de marcadores de genotipificación en la caracterización molecular de una población de aislamientos clínicos de Fusarium en Colombia

Introduction: Fusarium is a very heterogeneous group of fungi, difficult to classify, with a wide range of living styles, acting as saprophytes, parasites of plants, or pathogens for humans and animals. Prevalence of clinical fusariosis and lack of effective treatments have increased the interest in the precise diagnosis, which implies a molecular characterization of Fusarium populations. Objective: We compared different genotyping markers in their assessment of the genetic variability and molecular identification of clinical isolates of Fusarium. Materials and methods: We evaluated the performance of the fingerprinting produced by two random primers: M13, which amplifies a minisatellite sequence, and (GACA)4, which corresponds to a simple repetitive DNA sequence. Using the Hunter Gaston Discriminatory Index (HGDI), an analysis of molecular variance (AMOVA), and a Mantel test, the resolution of these markers was compared to the reference sequencing-based and PCR genotyping methods. Results: The highest HGDI value was associated with the M13 marker followed by (GACA)4. AMOVA and the Mantel tests supported a strong correlation between the M13 classification and the reference method given by the partial sequencing of the transcription elongation factor 1-alpha (TEF1-α) and rDNA 28S. Conclusion: The strong correlation between the M13 classification and the sequencing-based reference together with its higher resolution demonstrates its adequacy for the characterization of Fusarium populations.

Introducción. Fusarium es un grupo heterogéneo de hongos, difícil de clasificar y con una amplia gama de estilos de vida, que actúa como saprófito, parásito de plantas o patógeno de humanos y animales. La prevalencia de la fusariosis clínica y la falta de tratamientos han incrementado el interés en su diagnóstico preciso, lo que conlleva la caracterización molecular de las poblaciones. Objetivo. Comparar marcadores de genotipificación en la evaluación de la variabilidad genética e identificación de aislamientos clínicos de Fusarium. Materiales y métodos. Se evaluó la huella genética producida por dos cebadores aleatorios: M13, que amplifica una secuencia minisatélite, y (GACA)4, que corresponde a una secuencia repetitiva de ADN. Utilizando el índice discriminatorio de Hunter Gaston (HGDI), el análisis de varianza molecular (AMOVA) y una prueba de Mantel, se comparó la resolución de estos marcadores con métodos de genotipificación basados en secuenciación y PCR. Resultados. El mayor HGDI se asoció con el marcador M13, seguido de (GACA)4. Las pruebas AMOVA y Mantel mostraron correlación entre las clasificaciones obtenidas con M13 y la referencia basada en la secuenciación parcial del factor de elongación de transcripción 1-alfa (TEF1-α) y el ADNr 28S. Conclusión. La fuerte correlación entre la clasificación obtenida con M13 y el método de referencia, así como su alta resolución, demuestran su idoneidad para la caracterización de poblaciones de Fusarium.

Caries and genetic variability of streptococcus mutans / Caries y variabilidad genética de streptococcus mutans

In the last two decades, the increase in population genetics studies has contributed to elucidating important questions about the evolution of the pathogenesis of bacteria of clinical interest. The objective of this study is to revise and update the knowledge of the last fifteen years regarding the genetic variability of Streptococcus mutans and their association with dental caries. Streptococcus mutans, one of the most widely distributed bacteria in the world, are heavily associated with this condition. This research shows the results of numerous studies carried out in various countries that, using molecular and biochemical methods, revealed associations between different serotypes and caries activity. In addition, it is reported that the population genetics structure of Streptococcus mutans in Argentina is highly recombinant, which reflects the largest waves of human immigration that occurred in the 19th and 20th centuries. On the other hand, demographic analysis suggests that these bacteria experienced a population expansion that coincided with the beginning of agricultural development.

En las últimas dos décadas el incremento de los estudios de genética de poblaciones ha contribuido a dilucidar cuestiones importantes sobre la evolución de la patogénesis de bacterias de interés clínico. El objetivo de este trabajo es realizar una actualización sobre los conocimientos de los últimos quince años referidos a la variabilidad genética de Streptococcus mutans y su relación con la caries dental. Streptococcus mutans, de amplia distribución mundial, es una de las bacterias más fuertemente asociada a dicha enfermedad. En este trabajo se muestran resultados de numerosos estudios realizados en diferentes países que utilizando métodos moleculares y bioquímicos revelaron asociaciones entre diferentes serotipos y la actividad de caries. Además, se reporta que la estructura genética poblacional de Streptococcus mutans de Argentina es de alto nivel recombinante, lo que reflejaría las grandes oleadas inmigratorias humanas ocurridas en los siglos 19thy 20th. Por otra parte, los análisis demográficos sugieren que esta bacteria experimentó una expansión poblacional coincidente con el comienzo del desarrollo de la agricultura

Polymorphisms of 19 Autosomal STR Loci in Sichuan Han Population and Their Forensic Application / 法医学杂志

Objective To investigate the allele distribution, population genetics parameters and genetic analysis of neighboring populations of 19 autosomal STR loci in Sichuan Han population, and to evaluate their forensic application value. Methods The Goldeneye?? DNA ID system 20A was used to perform multiplex PCR amplification and allelic gene typing of 19 STR loci in 1 201 unrelated Han individuals from Sichuan Province. Allele frequencies and population genetics parameters were calculated. The Nei's genetic distances between Sichuan Han population and 12 previously reported populations were analyzed. Multidimensional scaling and principal component analysis were carried out and phylogenetic trees were also constructed. Results The heterozygosity of 19 STR loci ranged from 0.617 0 to 0.915 1, their discrimination power ranged from 0.777 4 to 0.986 5, matching probability ranged from 0.013 5 to 0.222 6, polymorphism information content ranged from 0.546 4 to 0.910 5, probability of exclusion ranged from 0.311 8 to 0.826 3 （triplet） and from 0.197 9 to 0.712 1 （biplet）, and no significant deviations from Hardy-Weinberg equilibrium were observed. Based on the results of multidimensional scaling, principal component analysis and phylogenetic trees of the genetic distances between Sichuan Han population and the other 12 populations, Sichuan Han population was closest to Hubei Han population and was farthest to Xinjiang Uygur population. Conclusion The 19 autosomal STR loci showed a high polymorphism and discriminating ability in Sichuan Han population, which can provide a data foundation for personal identification, paternity test and population genetics study.

Interacciones génicas implicadas en la aparición anticipada de cáncer de mama invasor en la población "paisa" - Colombia / Gene interaction implicated in genetic anticipation of invasive breast cancer in a "paisa" population - Colombia

Resumen El cáncer de mama invasor es una neoplasia de origen multifactorial en el cual están involucrados tanto componentes genéticos, como no genéticos, los cuales pueden modular su aparición temprana. El objetivo de este estudio es evaluar la participación de los componentes genéticos. Metodología: se analizaron 165 mujeres con cáncer de mama pertenecientes a la población "paisa" y estratificadas por edad de diagnóstico. Se evaluaron variables no genéticas y, de forma indirecta, variables genéticas usando marcadores tipo short tándem repeats (STR). Resultados: no se detectaron diferencias en cuanto a los factores de riesgo no genético entre pacientes mayores y menores de 50 años, ni al evaluar los genes de forma individual. Al comparar combinaciones genéticas se detectaron dos interacciones génicas en mujeres menores de 50 años: BRCA2-BRCA1 (p= 0,04) y BRCA2-ATM (p= 0,008). Conclusión: estos resultados sugieren la participación de la interacción de dichos genes en la aparición de cáncer de mama antes de los 50 años. Dado que el estudio se hizo con marcadores indirectos es necesario realizar estudios posteriores para identificar las mutaciones funcionales que soporten estos hallazgos.

Abstract Invasive breast cancer is a multifactorial neoplasm, involving both genetic and non-genetic components that modulate their early appearance of the disease. The aim of this study was to evaluate the contribution of genetic factors and disease. Methodology: 165 breast cancer patients stratified by age and belonging to the "paisa" population participated in the study. No genetic variables were controlled, and genetic variables were indirectly evaluated using short tandem repeats (STR) markers. Results: No differences were detected in non-genetic risk factors among patients older and younger than 50 years, not even in the individual evaluation of genes. When genetic combinations were evaluated, two interactions were detected in women younger than 50 years: BRCA2-BRCA1 (p= 0,04) and BRCA2-ATM (p= 0,008). Conclusion: These results suggest the involvement of gene interaction BRCA1-BRCA2 and BRCA2-ATM genes in the case of early onset of breast cancer (before the age of 50). Since the study was made with indirect markers, is necessary to perform further studies to identify the functional mutations that support these findings.

Genetic Polymorphism of Y Chromosome Haplogroup D-M174 in East Asian Populations / 法医学杂志

Objective To explore the genetic polymorphism of Y chromosome D-M174 haplogroup and sub-haplogroups in East Asia. Methods The samples of 1 426 unrelated male individuals from East Asia were collected, and then 7 Y chromosome haplogroup D-M174 and the Y-SNP of its sub-haplogroups were detected with mini-sequencing. The 22 Y-STR genotypes were detected with DNA Typer™ Y26 kit. The haplogroup was analyzed using direct counting method, heatmap, phylogenetic cluster and network graph cluster, and then distribution of genetic polymorphism and the clustering relation between populations and samples of Y chromosome D haplogroup were discussed. Results Haplogroup D-M174 were distributed mostly among Tibetans （40.96%）and Japanese （35.71%）, while less or none were distributed among the surrounding areas of Tibet and other areas. Conclusion The geographical distribution of Y chromosome D-M174 haplogroup in East Asian populations has significant characteristics.

Detection of Ancestry Information of Urumqi Mongolians Based on the AIM-InDels Loci Multiplex System / 法医学杂志

Objective To explore the genetic background and structure of Urumqi Mongolians, the previously developed 39-AIM-InDels panel for ancestry inference was utilized in the present study. Methods The blood samples of 145 unrelated healthy Urumqi Mongolian individuals were collected and genotyped. The compositions of ancestry information of Urumqi Mongolians were studied with 17 different populations from three continents （East Asia, Europe and Africa） as reference populations. Then, multiple population genetics and bioinformatics analysis methods were applied, the Fst and DA values between matched populations were compared and analyzed, PCA analysis was performed and a phylogenetic tree was constructed. The proportions of ancestry information components of Urumqi Mongolians were analyzed with Structure software, etc. Results The ancestry information components of Urumqi Mongolian group in different intercontinental populations accounted for 89%, 7%, and 3% of East Asian, European, and African populations, respectively. Compared with other intercontinental populations, Urumqi Mongolian group and East Asian populations have lower Fst and DA values, and they were in the same cluster in PCA analysis as well. In a phylogenetic tree, the Urumqi Mongolian group was in the same branch as East Asian populations. Conclusion Urumqi Mongolian group had relatively close genetic relationships with East Asian populations, and the proportion of its East Asian ancestry was about 89%.

Estimation of Anadara tuberculosa genetic diversity in five mangroves from Tumaco, using Cytochrome oxidase I enzyme / Estimación de la diversidad genética de Anadara tuberculosa en cinco manglares de Tumaco, utilizando la enzima citocromo oxidasa I

ABSTRACT Objective . To estimate the genetic diversity of the Anadara tuberculosa en five mangrove swams of Tumaco, Nariño, Colombia using as a mitocondrial molecular marker the cytochromo oxidase sub-unit I (COI). Materials and methods. A total of 50 individuals were collected from the San Jorge, La Tiburonera, El Pajal, La Playa y Bajito Vaquería mangrove swamps, randomly selecting 10 specimens of each zone. The tissue sample was worked with absolute alcohol at ambient temperature in microtubes. DNA was extracted, and the mitocondrial DNA was amplified using the PCR technique (polymerase chain reaction). The amplified and quantified products of PCR were sequenced on both sides (Macrogen). Each one of the obtained sequences was edited and aligned. Later, the parameters of genetic diversity (haplotypical and nucleotidical) were measured, and the analysis of distribution between frequency pairs (Mistmach distribution) was elaborated. Finally, the analysis of nucleotidic variation and population structure (AMOVA) was completed. Results. The amplified product gene weighed 710 bp. The haplotypical diversity reported for all the populations was high (0.683±0.060) and the reported nucleotídical diversity was low for all the populations (0.040±0.020). The AMOVA results indicate that the variance amongst populations is low (4.20%) and that the variance within populations is high (95.80%). Conclusions. The studied populations are not structured and although there is a decrease of natural banks, the genetic diversity is high.

RESUMEN Objetivo . Estimar la diversidad genética de Anadara tuberculosa en cinco manglares de Tumaco Nariño, Colombia utilizando como marcador molecular mitocondrial la subunidad I de la citocromo oxidasa (COI). Materiales y métodos. Se colectaron en total 50 individuos de los manglares San Jorge, La Tiburonera, El Pajal, La Playa y Bajito Vaquería, tomando 10 ejemplares al azar de cada zona. La muestra de tejido se fijó con alcohol absoluto a temperatura ambiente en microtubos. Se extrajo y amplificó el ADN mitocondrial mediante la técnica de PCR (Polymerase Chain Reaction). Los productos de PCR amplificados y cuantificados se secuenciaron por ambos lados (Macrogen). Una vez se obtuvo las secuencias, se editó y alineo cada secuencia. Posteriormente, se midió los parámetros de diversidad genética (haplotípica y nucleotídica) y se elaboró el análisis de distribución entre pares de frecuencias (Mistmach distribution). Finalmente se efectuó el análisis de variación nucleotídica y la estructura poblacional (AMOVA). Resultados. El gen amplificado tuvo una longitud de 710 pb. La diversidad haplotípica reportada para todas las poblaciones fue alta (0.683±0.060) y la diversidad nucleotídica reportada fue baja para todas las poblaciones (0.040±0.020). Los resultados del AMOVA indican que la varianza entre poblaciones es baja (4.20%) y la varianza dentro de las poblaciones es alta (95.80%). Conclusiones. Las poblaciones estudiadas no se encuentran estructuradas y a pesar de la disminución de los bancos naturales de las poblaciones de Anadara tuberculosa, se estima que la diversidad genética es alta.

A influência da estratificação populacional na susceptibilidade genética ao diabetes mellitus tipo 1 em uma população brasileira / The influence of population stratification in genetic susceptibility to type 1 diabetes in a Brazilian population

A investigação de genes associados a doenças complexas em estudos caso-controle, baseada na frequência de variantes polimórficas, pode não ser adequada na presença de estratificação populacional advinda da mistura étnica, que é uma das características da população brasileira. Torna-se, portanto, difícil utilizar esta metodologia, pelo risco de associações espúrias devido às diferenças no background genético dos indivíduos casos e controles. Marcadores informativos de ancestralidade (AIMs) podem ser aplicados para estimar ancestralidade e corrigir estas distorções. As mesmas variantes genéticas de susceptibilidade para o diabetes tipo 1 autoimune (DM1A) como os alelos HLADR3- DR4 e os polimorfismos do PTPN22, CTLA4 e VNTR-INS presentes em caucasianos não foram sempre encontradas com a mesma frequência na nossa população com DM1A, ou conferiram risco menor quando presentes. Tais diferenças podem advir da nossa miscigenação. Portanto, no presente estudo, objetivou-se: 1) Analisar uma amostra de portadores de DM1A da cidade de São Paulo e controles não diabéticos, utilizando marcadores genéticos autossômicos de ancestralidade, identificando os componentes ancestrais individuais e os da população, permitindo assim, maior compreensão da sua potencial estratificação; 2) Verificar o papel dos alelos do sistema HLA-DR e DQ, dos polimorfismos dos genes PTPN22, CTLA4 e INS-VNTR, na predisposição à doença, corrigindo para o viés introduzido pela estratificação da nossa população. Materiais e métodos: 915 pacientes com DM1A, idade de 24,6±13,0 anos, 81,7% autorreferidos brancos e 789 controles, idade 28,5 ± 11,5 anos, 65,6% autorreferidos brancos participaram do estudo. A genotipagem dos 93 marcadores informativos de ancestralidade foi realizada por meio da plataforma BeadXpress (Illumina, EUA). A composição ancestral dos indivíduos foi caracterizada pelo programa Structure 2.3, e os alelos e variantes dos genes candidatos, testados por...

The investigation of genes associated with complex diseases in case-control studies, based on the frequency of polymorphic variants, may not be appropriate in the presence of population stratification arising from the ethnic admixture, which is characteristic of the Brazilian population. It is therefore difficult to apply this method, due to the risk of spurious associations related to differences in the genetic background of individual cases and controls. Ancestry informative markers (AIMs) can be used to estimate ancestry and correct these distortions. The same genetic variants of susceptibility to type 1 autoimmune diabetes (T1AD) like HLA- DR3 -DR4 alleles and polymorphisms in PTPN22, CTLA4 and VNTR-INS genes usually present in caucasians were not always found at the same frequency in our population with T1AD, or conferred lower risk when present. These discrepancies may result from our miscigenation. Therefore, in this study, we aimed to: 1) analyze a sample of patients with T1AD and health controls, mostly living in São Paulo, using genetic autosomal markers of ancestry, to identify the ancestry of individual components and of the population, that could identify its potential stratification; 2) Evaluate the role of HLA-DR and -DQ alleles and polymorphisms of PTPN22, CTLA4 and INSVNTR genes in the predisposition to disease, correcting for the bias introduced by the stratification of our population. Methods: 915 patients with T1D, aged 24.6±13.0 years, 81.7% self-reported as white and 789 controls, aged 28.5±11.5 years, 65.6% self-reported as white participated of the study. Genotyping of 93 informative markers was performed by BeadXpress platform (Illumina, USA). The ancestry composition of individuals was characterized by Structure 2.3 program, and variants and alleles of candidate genes were tested using structured association analysis with the STRAT program. Results: The european ancestry prevailed in T1AD and control groups (77% and...

Patrones de consumo y genotipos determinantes de la tolerancia al alcohol: estudio en estudiantes universitarios de Santiago de Chile / Alcohol consumption patterns and genotypes determining alcohol tolerance in Chilean university students

Background: Alleles involved in inefficient (ADH1B2*2 and ALDH2*2) or efficient (SNP6, ADH4 gene) alcohol metabolism may influence the risk of alcoholism. Alcoholism susceptibility has been classified as protector and risk-dependence phenotypes, associated with inefficient and efficient alcohol genetic metabolizing variants, respectively. Aim: To investigate the possible association between genetic protective and risk-dependence variants and alcohol intake patterns. Material and Methods: Saliva DNA samples were obtained and the AUDIT (Alcohol Use Disorders Identification Test) questionnaire was applied to 210 university students aged between 18 and 25 years old. Results: No statistically significant association between protective or risk-dependence genetic variants and alcohol pattern intake was detected. However, new categories of alcohol intake patterns-not included in the AUDIT questionnaire-were identified. Conclusions: No association between the protector and risk-dependence phenotypes and patterns of alcohol consumption was detected in this sample of students.

Genetic polymorphism of 30 autosomal InDel loci in Chinese uygur population residing in Xinjiang / 解放军医学杂志

Objective To investigate the genetic data of 30 insertion deletion polymorphism (InDel) loci included in Investigator® DIPplex in Uygur population from Xinjiang, and evaluate its application in forensic medicine. Methods Allele frequencies, population genetics parameters of the 30 InDels were determined in 223 unrelated Uygur individuals with Investigator® DIPplex, and they were statistically analyzed and compared with available data of other populations of different races from different regions. Results After Bonferroni's correction, there were no significant departure from Hardy-Weinberg equilibrium or linkage disequilibrium between the loci. The average heterozygosity (Ho) was 0.468 6, the mean discrimination power (DP) was 0.609 5, and the total probability of discrimination power (TDP) reached 0.999 999 999 995. The cumulative probability of exclusion was 0.995 478 in trio cases (CPEtrio) and 0.972 007 in duo cases (CPEduo). The genetic distance between Uygur and Kazakh was closer than those between Uygur and other populations, such as African American. Conclusion Multiplex detection of the 30 InDel loci revealed a moderately high polymorphic genetic distribution in Chinese Uygur population residing in Xinjiang, demonstrating that the Investigator® DIPplex kit can be used as a supplementary tool for human identity tests, especially in challenging DNA cases.

Medidas morfofuncionais do coração obtidas por ressonância magnética em brasileiros / Morphological and functional measurements of the heart obtained by magnetic resonance imaging in Brazilians

FUNDAMENTO: Medidas ainda hoje utilizadas como referência na ressonância magnética cardíaca foram obtidas principalmente de estudos realizados em populações norte-americanas e europeias. OBJETIVO: Obter medidas do diâmetro diastólico, diâmetro sistólico, volume diastólico final, volume sistólico final, fração de ejeção e massa miocárdica dos ventrículos esquerdo e direito em brasileiros. MÉTODOS: Foram submetidos à ressonância magnética cardíaca, utilizando técnica de precessão livre em estado de equilíbrio, 54 homens e 53 mulheres, com idade média de 43,4 ± 13,1 anos, assintomáticos, sem cardiopatias. RESULTADOS: As médias e os desvios padrão dos parâmetros do ventrículo esquerdo foram: diâmetro diastólico = 4,8 ± 0,5 cm; diâmetro sistólico = 3,0 ± 0,6 cm; volume diastólico final = 128,4 ± 29,6 mL; volume sistólico final = 45,2 ± 16,6 mL; fração de ejeção = 65,5 ± 6,3%; massa = 95,2 ± 30,8 g. Para o ventrículo direito, foram: diâmetro diastólico = 3,9 ± 1,3 cm; diâmetro sistólico = 2,5 ± 0,5 cm; volume diastólico final = 126,5 ± 30,7 mL; volume sistólico final = 53,6 ± 18,4 mL; fração de ejeção = 58,3 ± 8,0% e massa = 26,1 ± 6,1 g. As massas e os volumes foram significativamente maiores nos homens, exceto para o volume sistólico final do ventrículo esquerdo. A fração de ejeção do ventrículo direito foi significativamente maior nas mulheres. Houve correlação significativa e inversa do volume sistólico do volume direito com o aumento da idade. CONCLUSÃO: Este estudo descreveu, pela primeira vez, medidas cardíacas obtidas pela ressonância magnética cardíaca em brasileiros assintomáticos, sem cardiopatias, mostrando diferenças de acordo com o gênero e a idade.

BACKGROUND: Still today, measurements used as a reference in the cardiac magnetic resonance imaging have been obtained mainly from studies carried out in North-American and European populations. OBJECTIVE: To obtain measurements of the diastolic diameter, systolic diameter, end diastolic volume, end systolic volume, ejection fraction, and myocardial mass of the left and right ventricles in Brazilians. METHODS: 54 men and 53 women, with mean age of 43.4 ± 13.1 years, asymptomatic, with no cardiomyopathies, have been subjected to the cardiac magnetic resonance imaging, using a balanced steady state free precession technique. RESULTS: The averages and the standard deviations of the parameters for the left ventricle have been: diastolic diameter = 4.8 ± 0.5 cm; systolic diameter = 3.0 ± 0.6 cm; end diastolic volume = 128.4 ± 29.6 mL; end systolic volume = 45.2 ± 16.6 mL; ejection fraction = 65.5 ± 6.3%; mass = 95.2 ± 30.8 g. For the right ventricle, they have been: diastolic diameter = 3.9 ± 1.3 cm; systolic diameter = 2.5 ± 0.5 cm; end diastolic volume = 126.5 ± 30.7 mL; end systolic volume = 53.6 ± 18.4 mL; ejection fraction = 58.3 ± 8.0%, and mass = 26.1 ± 6.1 g. The masses and the volumes were significantly greater in the men, except for the end systolic volume of the left ventricle. The ejection fraction of the right ventricle has been significantly greater in the women. There has been a significant and inverted correlation of the systolic volume of the right volume with the progression of the age. CONCLUSION: This study has described, for the first time, cardiac measurements obtained through the cardiac magnetic resonance imaging in Brazilians, asymptomatic, with no cardiomyopathies, showing differences in accordance with gender and age.

Gene polymorphisms and distribution features of glutathione S-transferase Omega-1 gene in Ala140Asp site in 16 Chinese populations / 中国地方病学杂志

Objective To investigate gene polymorphisms and distribution features of glutathione Stransferase Omega-1 (GSTO 1 ) gene in Ala 140Asp site in 16 Chinese populations.MethodsA total of 1369 samples were from the human genome project(HGP)-the establishment and preservation program of Chinese minority genetic resources.The phenotypes of Ala/Ala (C/C),Ala/Asp (C/A),and Asp/Asp (A/A) of GSTO1 Ala140Asp were determined by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP).With analysis of molecular variance(AMOVA),the genetic variation levels among nations and regions were analyzed by estimating the evolutionary distance of alleles or genotypes.ResultsOf the 1369 individuals analyzed,979 (71.51％) were carriers of the wild homozygous allele Ala/Ala(C/C),365 (26.66％) were heterozygotes Ala/Asp(C/A) and 25 (1.83％) were mutant homozygotes Asp/Asp(A/A),with an overall frequency of the GSTO 1 mutant allele A 15.16％ [ (365 +50)/( 1369 × 2)].AMOVA analysis showed that the difference was statistically significant(P ＜ 0.05) of genetic variations of GSTO1 gene Ala140Asp among the 14 ethnic groups,and was significant between the northem and southern populations (P ＜ 0.05 ).Conclusion In different regions and populations the GSTO1Ala140Asp mutant allele frequencies are different.

Bajo polimorfismo en el sistema de antígenos de leucocitos humanos en población mestiza colombiana / Low HLA polymorphism in Colombian mestizos

Objetivo. Este trabajo tiene como objetivo describir la frecuencia de alelos y de haplotipos de antígenos HLA de clases I y II en población mestiza colombiana. Metodología. Se estudiaron 197 individuos colombianos no emparentados y 157 individuos emparentados que conformaban 53 familias, provenientes de diferentes regiones del país, remitidos para estudios de HLA de clases I y II por el método PCR-SSP a los laboratorios de inmunología del Hospital Militar Central de Bogotá y al Instituto de Referencia Andino. Resultados. El haplotipo HLA-A*24 B*35 DR*04 fue el más frecuente en la población estudiada, lo cual concuerda con otros estudios de mestizos colombianos. Conclusiones. El desequilibrio de Hardy-Weinberg hallado en la población analizada en el presente estudio, debe alertar sobre una eventual reducción en el repertorio de respuesta inmunitaria en los colombianos, lo cual podría ser el origen de una consecuente fragilidad de la población frente a nuevas infecciones que podrían convertirse en epidemias.

Objective: This paper aims to describe the allele frequency and haplotype of HLA class I and II molecules in a Colombian mestizo population. Methodology: HLA class I and II molecules on 197 unrelated Colombian individuals and 157 unrelated individuals making up 53 families from different regions of the country were studied at the Immunology Laboratory at the Military Hospital Central of Bogotá and at the Instituto de Referencia Andino by the PCR-SSP method. Results: The haplotype HLA-A * 24 B*35 DR*04 was the most common, which is consistent with other studies carried out in Colombian mestizos. Conclusions: The Hardy-Weinberg disequilibrium found in the population analyzed in this study should alert on a possible reduction of the immune response repertoire in Colombia, which could be the origin of a consequent fragility of the population in face of new infections that could eventually become epidemic.

Diferenciación genética de tres poblaciones colombianas de Triatoma dimidiata (Latreille, 1811) mediante análisis molecular del gen mitocondrial ND4 / Genetic differentiation of three Colombian populations of Triatoma dimidiata (Heteroptera: Reduviidae) by ND4 mitochondrial gene molecular analysis

Introducción. Triatoma dimidiata es el segundo vector más importante de la enfermedad de Chagas en Colombia, después de Rhodnius prolixus. El conocimiento de la composición genética y la diferenciación de poblaciones es fundamental para el adecuado diseño e implementación de estrategias de control y vigilancia vectorial. Objetivo. Determinar el nivel de variabilidad y diferenciación genética en tres poblaciones colombianas de T. dimidiata provenientes de distintas localidades y hábitats, mediante el análisis molecular de un fragmento del gen mitocondrial ND4. Materiales y métodos. Se analizó el nivel de polimorfismo y la estructura genética de dos poblaciones silvestres de los departamentos de La Guajira (n=10) y Santander (n=10), y de una población intradomiciliaria (n=15) y peridomiciliaria (n=5) del Cesar. Para tal fin, se analizaron las secuencias de nucleótidos de un fragmento del gen mitocondrial ND4. Resultados. T. dimidiata en Colombia demostró tener gran diversidad genética, tanto a nivel de nucleótidos (π: 0,034) como de haplotipo (Hd: 0,863), además de una significativa estructuración de población (fST: 0,761) con un bajo número de migrantes (Nm: 0,157). Las distancias genéticas y las diferencias en los niveles de variabilidad genética entre las tres poblaciones fueron coherentes con una posible subdivisión de población.Conclusión. Este trabajo demostró diferenciación genética entre las poblaciones de T. dimidiata de La Guajira, Cesar y Santander. Se sugiere una posible relación entre tal subdivisión y algunas características eco-epidemiológicas que posee T. dimidiata en el centro-oriente y en el norte de Colombia. Finalmente, este trabajo describe, por primera vez, la utilidad del ND4 como un marcador molecular para el estudio de poblaciones naturales de T. dimidiata.

Introduction. Triatoma dimidiata is the second most important vector of Chagas disease in Colombia after Rhodnius prolixus. Population genetic studies are essential for the adequate design and implementation of vector control and surveillance strategies. Objective. The level of genetic variability and population differentiation was surveyed among three Colombian populations of T. dimidiata from different geographic locations and ecotopes, using ND4 mitochondrial gene. Materials and methods. Genetic comparison was made between two wild populations from La Guajira (n=10) and Santander (n=10) provinces, and one intra (n=15) and one peridomiciliary (n=5) population from the Cesar province. The polymorphism frequencies of the ND4 mitochondrial gene sequence were analyzed to deduce population structure based on the 40 samples. Results. Colombian T. dimidiata showed a high nucleotide (π: 0.034) and haplotype diversity (Hd: 0.863), as well as significant population subdivision (fST: 0.761) and a low migration rate (Nm: 0.157). Genetic distances and variability differences among populations indicate distinct population subdivision amongst the three provinces. Conclusion. ND4 proved useful in elucidating the significant genetic differentiation that has occurred among T. dimidiata populations from La Guajira, Cesar and Santander. The analysis suggested a relationship between population subdivision and some eco-epidemiological attributes of this vector from the central eastern and northwestern regions of Colombia.

Origen de los Changos: Análisis de ADNmt antiguo sugiere descendencia de pescadores de la cultura Chinchorro (7.900 - 4.000 A.P.) / Origins of Changos: Mitochondrial DNA analysis suggests Chinchorro culture fishermen ancestry

Sophisticated molecular genetics techniques allow the typification and posterior comparison of antique haplogroups and mitochondrial DNA sequences from prehistoric groups with contemporary populations. This adds a chronological dimension to these studies and contributes to have a better knowledge of the genetic composition of the Chilean population. This article gives scientific support, using molecular methodology, to the alleged biological links that joined the descendants of proto historic Chango fishermen from Puposo cove, a place located 15 kilometers north of Taltal, with prehistoric fishermen from Chinchorro culture, that developed in Northern Chile and Southern Peru between 7900 and 4000 A.C.

Genómica nutricional: una aproximación de la interacción genoma-ambiente: [revisión] / Nutritional genomics: an approach to the genome-environment interaction: [review]

Nutritional genomics forms part of the genomic sciences and addresses the interaction between genes and the human diet, its influence on metabolism and subsequent susceptibility to develop common diseases. It encompasses both nutrigenomics, which explores the effects of nutrients on the genome, proteome and metabolome; and nutrigenetics, that explores the effects of genetic variations on the diet/disease interaction. A number of mechanisms drive the gene/diet interaction: elements in the diet can act as links for transcription factor receptors and alter intermediary concentrations, thereby modifying chromatin and impacting genetic regulation; affect signal pathways, regulating phosphorylation of tyrosine in receptors; decrease signaling through the inositol pathway; and act through epigenetic mechanisms, silencing DNA fragments by methylation of cytosine. The signals generated by polyunsaturated fatty acids are so powerful that they can even bypass insulin mediated lipogenesis, stimulated by carbohydrates. Some fatty acids modify the expression of genes that participate in fatty acid transport  by lipoproteins. Nutritional genomics has myriad possible therapeutic and preventive applications: in patients with enzymatic deficiencies; in those with a genetic predisposition to complex diseases such as dyslipidemia, diabetes and cancer; in those that already suffer these diseases; in those with altered mood or memory; during the aging process; in pregnant women; and as a preventive measure in the healthy population.

Epidemiología y genética: alianza estratégica en el nuevo milenio? / Epidemiology and genetics: a strategic alliance in the new millennium?

Although the information derived from biological markers could conceivably be used to overcome some of the problems intrinsic to virtually all epidemiologic study designs­case definition, true exposure level, host susceptibility and resistance to factors of interest, the misclassification of study sub- 44 Rev Panam Salud Publica/Pan Am J Public Health 17(1), 2005 Opinión y análisis • Opinion and analysis jects (false positive and false negative test results), etc.­, we are still unable to resolve all such problems with the tools available at present. Biological markers seem more promising as potential indicators of the degree of susceptibility than as indicators of disease occurrence, an application requiring further technical refinement. Currently biological markers are employed in public health mainly to screen for particular diseases. Unfortunately, these markers have their limitations. For one thing, it is unlikely that they will completely eliminate the problem of false positive and false negative results, since DNA from solid tumors undergoes slight degradation due to necrosis and since genetic markers are susceptible to the effects of exposure to medication, diet, sex, ethnicity, and even the circadian cycle. And even if false positives and negatives were ultimately eliminated, it would be impossible to use many of the analytical tools based on two by two tables, such as the chi squared test, logistic regression, the Poisson regression, Cox' proportional hazards ratio, etc., since such tools rely on comparisons of the number of false positives and negatives in the exposed and non-exposed groups. Finally, albeit no less important, certain ethical issues must be carefully considered before allowing the massive use of human genetic markers, which could lead to violations of the rights of individuals, families, and communities if carried out in an indiscriminate, unregulated fashion. Epidemiology is rapidly broadening its scope, a trend that will continue into the future; new analytical tools will be developed, and the working hypotheses to which such tools will be applied will change. At present the scientific community is paying increased attention to this field of study, but more research and discussion are needed to respond to many of the questions for which we have no satisfactory answers yet

Study of candidate genes in type 2 diabetes mellitus in Chinese Han populations in Shandong / 中华内分泌代谢杂志

Objective To investigate the relationship between polymorphisms of candidate genes 〔glucokinase (GCK) gene, NIDDM1(D2S140) gene, fatty acid bindingprotein2(FABP2)gene〕and type 2 diabetes mellitus (DM) in Shandong Chinese Han population. Methods Short tandem repeat (STR) region polymorphisms of GCK gene, NIDDM1 gene and FABP2 gene were analyzed with the polymerase chain reaction and polyacrylamide sequencing gel in 107 patients with type 2 diabetes mellitus and 105 normal subjects. The subjects studied were unrelated and they are Chinese Hans living in Shandong province and no diabetes family history was revealed. Results A5 allele of GCK gene and B2 allele of NIDDM1 gene were positively related with type 2 diabetes (RR=15.70, P0.05). Logistic regression analysis showed that A5 allele and B2 allele were among the risk factors of type 2 diabetes. Conclusion Polymorphic microastellite repeat markers at the glucokinase gene and the NIDDM1 (D2S140) gene locus are associated with type 2 diabetes in Chinese. The polymorphism at the FABP2 locus is not a genetic marker for type 2 DM in Chinese Hans.