ABSTRACT
Introducción: La Sociedad Latinoamericana de Genética Forense, desde el año 2003 organiza ejercicios colaborativos de comparación interlaboratorios a fin de apoyar el fortalecimiento de los laboratorios de Genética Forense de Latinoamérica, siendo el ejercicio de calidad de SLAGF el único que incluye muestras óseas. Objetivo: Presentar los resultados del análisis del ejercicio de calidad de SLAGF correspondientes al año 2023. Metodología: Se diseñó un ejercicio práctico con cinco muestras: dos hisopados bucales (M1 y M2), una muestra de sangre en FTA (M3), una muestra mezcla 1:1 de sangre- sangre en FTA (M4) y un resto óseo (M5), Se envió a los laboratorios un ejercicio teórico con cinco casos; dos de los cuales eran opcionales. Al igual que cinco ejercicios teóricos para los peritos independientes participantes. Por primera vez se incluyó un ejercicio de IVD opcional, los ejercicios están disponibles en: http://slagf.org/resultados-control- slagf-2023/x Resultados: Participaron 30 laboratorios y 12 peritos independientes. En el ejercicio práctico, la muestra cadavérica de restos óseos presentó los mayores desafíos, en la parte teórica fue el ejercicio de IVD. Conclusión: Los desafíos que enfrentan los laboratorios de Genética Forense Latinoamericanos, reflejados en el ejercicio de calidad de SLAGF 2023, son similares a los encontrados por otros grupos que realizan ejercicios de control de calidad en Genética Forense...(AU)
Subject(s)
Forensic Genetics , Laboratory Proficiency Testing , Quality Control , Forensic MedicineSubject(s)
Humans , Forensic Genetics , Forensic Microbiology/methods , DNA , Forensic Sciences , Human RightsABSTRACT
The GHEP-ISFG Working Group has recognized the importance of assisting DNA laboratories to gain expertise in handling DVI or missing persons identification (MPI) projects which involve the need for large-scale genetic profile comparisons. Eleven laboratories participated in a DNA matching exercise to identify victims from a hypothetical conflict with 193 missing persons. The post mortem database was comprised of 87 skeletal remain profiles from a secondary mass grave displaying a minimal number of 58 individuals with evidence of commingling. The reference database was represented by 286 family reference profiles with diverse pedigrees. The goal of the exercise was to correctly discover re-associations and family matches. The results of direct matching for commingled remains re-associations were correct and fully concordant among all laboratories. However, the kinship analysis for missing persons identifications showed variable results among the participants. There was a group of laboratories with correct, concordant results but nearly half of the others showed discrepant results exhibiting likelihood ratio differences of several degrees of magnitude in some cases. Three main errors were detected: (a) some laboratories did not use the complete reference family genetic data to report the match with the remains, (b) the identity and/or non-identity hypotheses were sometimes wrongly expressed in the likelihood ratio calculations, and (c) many laboratories did not properly evaluate the prior odds for the event. The results suggest that large-scale profile comparisons for DVI or MPI is a challenge for forensic genetics laboratories and the statistical treatment of DNA matching and the Bayesian framework should be better standardized among laboratories.
Subject(s)
Biometric Identification/methods , DNA Fingerprinting/methods , DNA/analysis , Databases, Genetic , Forensic Genetics/methods , Bayes Theorem , Cooperative Behavior , DNA/genetics , Disasters , Humans , Microsatellite Repeats , Pedigree , Portugal , SpainABSTRACT
In recent years there has been much attention to Argentinean population stratification. We were interested in assessing population stratification from a geographical perspective and summarizing it in form of maps. We mapped the genetic admixture of the extant male population in central and northern Argentina on the basis of forensic Y-chromosomal haplotypes. We addressed the question which group of genetically similar individuals is predominant in this area. Haplotypes containing seven Y-chromosomal short tandem repeat polymorphisms (Y-STRs), also known as microsatellites - DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393 - were constructed for 145 individuals, recruited in 10 provinces. 97 distinct haplotypes were clustered into four clusters according to molecular distances. A genetic geostatistical analysis was conducted with the open-source geographical information system GRASS GIS. For each haplotype cluster, the according frequency was spatially interpolated over the total study area. Juxtaposing the interpolation surfaces, we screened point-wisely the maximal frequency as well as the label of the respective cluster. The screening results were combined in one summary map. We repeated this procedure for the second maximal frequencies. The resulting maps subdivide the study area into continuous regions comprising one predominant group of similar haplotypes. The first summary map divides the study area into three regions and the second summary map divides the area into four regions. The results of our analysis indicate that two groups of similar European haplotypes alternatively dominate the largest extension of the Argentinean territory. A third group, including South-American haplotypes, dominates the indigenous northwestern Argentinean area. The last group, including worldwide dispersed haplotypes, preponderates in frequency in second place in central Argentina. Our findings confirm a widespread European paternal ancestry, a substantial Amerindian contribution in the northwest, as well as a considerable proportion of diverse paternal lineages. In this work, we further discuss these findings in reference to ethno-historical, genetic, and demographic information.
Subject(s)
Chromosomes, Human, Y , Genetics, Population , Geographic Information Systems , Haplotypes , Microsatellite Repeats , Argentina , DNA Fingerprinting/methods , Genetic Variation , Genotype , Humans , MaleABSTRACT
We present a case of deficient paternity with two presumptive fathers analyzed with 19 autosomic short tandem repeats (STRs) and resolved by means of the study of 12 Y-chromosome STRs. Fifteen autosomic STRs consensued from the commercial kit PowerPlex-16 (Promega) were analyzed, and a combined paternity index (PI(com)) of 13,811.215 and a probability of paternity (W) of 99.9999928% were obtained for presumptive father 1 and a PI(com) of 35,332.241 with a W of 99.9999971% for presumptive father 2.
Subject(s)
Microsatellite Repeats/genetics , Paternity , Child , Chromosomes, Human, Y , False Negative Reactions , Fathers , Forensic Genetics/methods , Humans , Male , Reagent Kits, DiagnosticABSTRACT
En Bolivia la población ameriñdia de la Amazonia, contiene cierto número de pequeños grupos humanos, que mantienen poco o ningún contacto con otros pueblos indígenas o con grupos humanos civilizados. Los estudios de la variabilidad del cromosoma Y, en poblaciones amerindias nativas han sido provechosos para comprender algunos aspectos de la historia genética. Con el objeto de investigar las posibles relaciones entre las distintas etnias que habitan Bolivia, se analizaron 9 marcadores microsatélites del cromosoma Y, (DYS393, DYS39O, DYS394, DYS392, DYS391, DYS385 1-II, DYS389 1-II). De esta manera se obtuvo 23 haplotipos diferentes y una alta frecuencia de algunos alelos, como el 13 para el locus DYS393 y DYS394. Estos resultados posiblemente se deban al componente amerindio, como lo indican otros estudios similares en este mismo tipo de poblaciones del continente americano
