Variability of PDYN and OPRK1 genes in four argentinian populations and its genetic association with clinical variables related to acute postsurgical pain / Variabilidad de los genes PDYN y OPRK1 en cuatro poblaciones argentinas y su asociación con variables clínicas relacionadas al dolor agudo post-quirúrgico

ABSTRACT Several population studies showed an association between variation in pain sensitivity and genetic polymorphisms located in Prodynorphin (PDYN) and Kappa Opioid Receptor (OPRK1) human genes. We analysed polymorphisms of these two genes to characterise their variation in Argentinian populations, as well as to evaluate their association with acute pain sensitivity. We studied 11 genetic markers in individuals from four locations in Argentina (Ciudad Autónoma de Buenos Aires, La Plata, Resistencia, and Misión Nueva Pompeya), calculated the population parameters, and evaluated the possible association among pain sensitivity, clinical, and genetic variables through a Generalised Estimating Equation model. High linkage disequilibrium was observed in the four populations for both genes, and significant differences were found among frequencies of Argentinian populations and those from other continents reported in the 1000 Genomes Project. Four PDYN gene polymorphisms from 3´ untranslated region and exon 4 showed association with acute pain sensitivity. One genotype of each of these polymorphisms was associated with a higher pain sensitivity, probably related with the activation of the N-methyl-D-aspartate (NMDA) receptors. We found a strong association with acute pain for the following clinical variables: 1) time after surgery, 2) intravenous klosidol supplied every 8 h, and 3) type of incision. Our results highlight the importance of a regional study of genetic variants which influence pain sensitivity and analgesic response.

RESUMEN La asociación entre la sensibilidad al dolor y los polimorfismos que presentan los genes humanos de prodinorfina (PDYN) y receptor opioide kappa (OPRK1) se ha evidenciado en distintos estudios poblacionales. Con el objetivo de caracterizar la variación de estos genes y evaluar su asociación con dolor agudo en la población argentina, analizamos 11 polimorfismos en individuos provenientes de cuatro localidades argentinas (Ciudad Autónoma de Buenos Aires, La Plata, Resistencia, y Misión Nueva Pompeya). Calculamos los parámetros poblacionales y evaluamos la posible asociación entre sensibilidad al dolor, variables clínicas y variables genéticas a través de un modelo de ecuación generalizada de estimación. Se observó alto desequilibrio de ligamiento para ambos genes en las cuatro poblaciones analizadas, y se encontraron diferencias significativas entre las frecuencias de poblaciones argentinas y las reportadas en el Proyecto 1000 Genomes para poblaciones de otros continentes. Cuatro polimorfismos de la región 3´UTR y el exón 4 de PDYN mostraron asociación con la sensibilidad al dolor agudo. En cada uno de estos polimorfismos, un genotipo resultó asociado con alta sensibilidad al dolor, probablemente en relación con la activación de receptores N-metil-D-aspartato (NMDA). Encontramos una fuerte asociación con dolor agudo para las siguientes variables clínicas: 1) tiempo post-cirugía, 2) administración intravenosa de klosidol cada 8 h, y 3) tipo de incisión. Nuestros resultados resaltan la importancia de realizar estudios regionales de variables genéticas que influyen en la sensibilidad al dolor y la respuesta analgésica.

X-chromosome data for 12 STRs: Towards an Argentinian database of forensic haplotype frequencies.

The analysis of X-chromosome STRs is useful in certain kinship cases for which autosomal markers provide insufficient statistical power. Particularly, powerful results are achieved in paternity cases with a daughter, when the alleged father is not accessible for analysis, contrarily to his unquestioned mother or daughter. However, representative haplotype frequencies for this type of markers are not available for some populations, as is the case of Argentina, which prevents the quantification of the proof in routine forensic analyses. In this work we present haplotype frequencies for the 12 X-chromosome STRs included in the Investigator Argus X-12 kit, as well as segregation data, obtained from the analysis of the genetic profiles of 457 father-daughter duos, which gave us information on 914 (unrelated) haplotypes from residents of all Argentinian provinces.

A GHEP-ISFG collaborative study on the genetic variation of 38 autosomal indels for human identification in different continental populations.

A collaborative effort was carried out by the Spanish and Portuguese Speaking Working Group of the International Society for Forensic Genetics (GHEP-ISFG) to promote knowledge exchange between associate laboratories interested in the implementation of indel-based methodologies and build allele frequency databases of 38 indels for forensic applications. These databases include populations from different countries that are relevant for identification and kinship investigations undertaken by the participating laboratories. Before compiling population data, participants were asked to type the 38 indels in blind samples from annual GHEP-ISFG proficiency tests, using an amplification protocol previously described. Only laboratories that reported correct results contributed with population data to this study. A total of 5839 samples were genotyped from 45 different populations from Africa, America, East Asia, Europe and Middle East. Population differentiation analysis showed significant differences between most populations studied from Africa and America, as well as between two Asian populations from China and East Timor. Low FST values were detected among most European populations. Overall diversities and parameters of forensic efficiency were high in populations from all continents.

Mutation rates at Y chromosome specific microsatellites.

A collaborative work was carried out by the Spanish and Portuguese ISFG Working Group (GEP-ISFG) to estimate Y-STR mutation rates. Seventeen Y chromosome STR loci (DYS19, DYS385, DYS389I and II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS460, DYS461, DYS635 [GATA C4], GATA H4, and GATA A10) were analyzed in a sample of 3,026 father/son pairs. Among 27,029 allele transfers, 54 mutations were observed, with an overall mutation rate across the 17 loci of 1.998 x 10(-3) (95% CI, 1.501 x 10(-3) to 2.606 x 10(-3)). With just one exception, all of the mutations were single-step, and they were observed only once per gametogenesis. Repeat gains were more frequent than losses, longer alleles were found to be more mutable, and the mutation rate seemed to increase with the father's age. Hum Mutat 26(6), 520-528, 2005. (c) 2005 Wiley-Liss, Inc.

Phylogenetic relationships among Robertsonian karyomorphs of Graomys griseoflavus (Rodentia, Muridae) by mitochondrial cytochrome b DNA sequencing.

Graomys griseoflavus (Waterhouse 1837) is a phyllotine murid rodent with a Robertsonian autosomal polymorphism, having been described 2n = 42, 41, 38, 37, 36, 35 and 34 karyomorphs, and proposed a chromosomal divergence pathway accounted by four sequential Robertsonian fusions. Sequences of a fragment (422 bp long) of the cytochrome b (cyt b) mitochondrial gene and its 5' flanking region (tRNA Glu) were obtained for 19 Graomys griseoflavus from different karyomorphs to infer phylogenetic relationships by using maximum parsimony. Outgroups considered for this analysis were the phyllotine rodents Phyllotis xanthopygus and Eligmodontia typus cyt b sequences. Three trees were produced showing the 2n = 38-34 karyomorphs grouped in a single clade while the 2n = 42-41 animals formed a different one. This is in agreement with a hypothesis of a single origin for 2n = 38-34 Robertsonian karyomorphs from the ancestral 2n = 42.

Variability of the F13B locus in South American populations.

A population study for the F13B locus was carried out in a total of 396 South American individuals. The analysis comprised new data from 5 Amerindian populations, existing data from 3 Amerindian populations, and I urban sample from La Plata, Argentina. In both pooled Amerindian and La Plata samples, 6 alleles were found. The individual Amerindian samples showed a lower number of alleles, changes in modal alleles, and restricted variability. Interpopulation comparisons revealed significant differences among samples from distinct geographical regions. Differences among the groups were also corroborated by the F(ST) statistic. Data support the hypothesis that genetic drift and gene flow influence Amerindian differentiation.

Characterization of ancestral and derived Y-chromosome haplotypes of New World native populations.

We analyze the allelic polymorphisms in seven Y-specific microsatellite loci and a Y-specific alphoid system with 27 variants (alphah I-XXVII), in a total of 89 Y chromosomes carrying the DYS199T allele and belonging to populations representing Amerindian and Na-Dene linguistic groups. Since there are no indications of recurrence for the DYS199C-->T transition, it is assumed that all DYS199T haplotypes derive from a single individual in whom the C-->T mutation occurred for the first time. We identified both the ancestral founder haplotype, 0A, of the DYS199T lineage and seven derived haplogroups diverging from the ancestral one by one to seven mutational steps. The 0A haplotype (5.7% of Native American chromosomes) had the following constitution: DYS199T, alphah II, DYS19/13, DYS389a/10, DYS389b/27, DYS390/24, DYS391/10, DYS392/14, and DYS393/13 (microsatellite alleles are indicated as number of repeats). We analyzed the Y-specific microsatellite mutation rate in 1,743 father-son transmissions, and we pooled our data with data in the literature, to obtain an average mutation rate of.0012. We estimated that the 0A haplotype has an average age of 22,770 years (minimum 13,500 years, maximum 58,700 years). Since the DYS199T allele is found with high frequency in Native American chromosomes, we propose that 0A is one of the most prevalent founder paternal lineages of New World aborigines.