Publications by authors named "María Conceiçao Vide"

9 Publications

  • Page 1 of 1

Allelic frequency distribution of 17 STRs from Identifiler and PowerPlex-16 in Central Portugal area and the Azores archipelago.

Forensic Sci Int Genet 2009 Dec 19;4(1):e1-7. Epub 2009 Jan 19.

Forensic Genetics Service, Centre Branch, National Institute of Legal Medicine, Coimbra, Portugal.

This study analyzes the allelic frequency distribution of 17 STRs contained in the AmpFlSTR Identifiler (Applied Biosystems) and PowerPlex16 System (Promega) commercial kits for two large population samples from the Azores archipelago (Portugal) (N=475) and from Central Portugal (N=2125). Likewise, it includes a comparative study among the population groups analyzed in this paper and those which history points out as originating from the first settlers of the Azores. All loci were highly polymorphic. The Central Portuguese area and the Azores archipelago population samples are in Hardy-Weinberg equilibrium for the 17 markers analyzed.
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http://dx.doi.org/10.1016/j.fsigen.2008.12.001DOI Listing
December 2009

STR analysis of artificially degraded DNA-results of a collaborative European exercise.

Forensic Sci Int 2004 Jan;139(2-3):123-34

Institut für Rechtsmedizin, Universität Mainz, Mainz, Germany.

Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.
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http://dx.doi.org/10.1016/j.forsciint.2003.10.002DOI Listing
January 2004

Results of the GEP-ISFG collaborative study on two Y-STRs tetraplexes: GEPY I (DYS461, GATA C4, DYS437 and DYS438) and GEPY II (DYS460, GATA A10, GATA H4 and DYS439).

Forensic Sci Int 2003 Aug;135(2):158-62

Institute of Legal Medicine, University of Santiago de Compostela, Compostela, Spain.

A collaborative exercise was carried out by the Spanish and Portuguese ISFG Working Group (GEP-ISFG) in order to evaluate the performance of two Y-chromosome STR PCR tetraplexes, which include the loci DYS461, GATA C4, DYS437 and DYS438 (GEPY I), and DYS460, GATA A10, GATA H4 and DYS439 (GEPY II). The participating laboratories were asked to type three samples for the eight markers, using a specific amplification protocol. In addition, two control samples, with known haplotypes, were provided. The results obtained by the 13 different participating laboratories were identical, except for two laboratories that failed to type correctly the same two samples for GATA C4. By sequence analyses, two different GATA C4 allele structures were found. One control sample (allele 21) and two questioned samples (allele 22, correctly typed by all the laboratories, and allele 25) presented the following repeat structure: (TCTA)4(TGTA)2(TCTA)2(TGTA)2(TCTA)n, but different from the one found for allele 26 in one sample included in this exercise, as well as in the second control sample (allele 23), namely (TCTA)4(TGTA)2(TCTA)2(TGTA)2(TCTA)2(TGTA)2(TCTA)n. The collaborative exercise results proved that both Y-tetraplexes produce good amplification results, with the advantage of being efficiently typed using different separation and detection methodologies. However, since GATA C4 repeat presents a complex structure, with alleles differing in sequence structure, efficient denaturing conditions should be followed in order to avoid typing errors due to sizing problems.
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http://dx.doi.org/10.1016/s0379-0738(03)00200-7DOI Listing
August 2003

Results of the GEP-ISFG collaborative study on the Y chromosome STRs GATA A10, GATA C4, GATA H4, DYS437, DYS438, DYS439, DYS460 and DYS461: population data.

Forensic Sci Int 2003 Aug;135(2):150-7

IPATIMUP, Institute of Pathology and Immunology of University of Porto, Porto, Portugal.

The Spanish and Portuguese ISFG Working Group (GEP-ISFG) carried out a collaborative exercise in order to asses the performance of two Y chromosome STR tetraplexes, which include the loci DYS461, GATA C4, DYS437 and DYS438 (GEPY I), and DYS460, GATA A10, GATA H4 and DYS439 (GEPY II). The groups that reported correct results in all the systems were also asked to analyse a population sample in order to evaluate the informative content of these STRs in different populations. A total of 1020 males out of 13 population samples from Argentina, Brazil, Costa Rica, Macao, Mozambique, Portugal and Spain were analysed for all the loci included in the present study. Haplotype and allele frequencies of these eight Y-STRs were estimated in all samples. The lowest haplotype diversity was found in the Lara (Argentina) population (95.44%) and the highest (99.90%) in Macao (China). Pairwise haplotype analysis showed the relative homogeneity of the Iberian origin samples, in accordance with what was previously found in the European populations for other Y-STR haplotypes (http://www.ystr.org). As expected, the four non-Caucasian samples, Macao (Chinese), Mozambique (Africans), Costa Rica (Africans) and Argentina (Lara, Amerindians), show highly significant Phist values in the pairwise comparisons with all the Caucasian samples.
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http://dx.doi.org/10.1016/s0379-0738(03)00199-3DOI Listing
August 2003

Y-chromosome STR haplotypes in two population samples: Azores Islands and Central Portugal.

Forensic Sci Int 2003 Jun;134(1):29-35

National Institute of Legal Medicine, Forensic Genetics of Coimbra, Largo da Sé Nova, 3000 213 Coimbra, Portugal.

The Y-chromosome haplotypes defined by nine STRs (DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392 and DYS393) were studied in 207 unrelated individuals from Central Portugal and 63 from Azores Islands. The most common haplotype in Central Portugal was shared by 3.4% of the males, while 160 haplotypes were unique. In Azores Islands the most common haplotype was shared by 6.4% of the males, while 40 haplotypes were unique. The values of haplotype diversity were 0.993 for Central Portugal and 0.976 for Azores Islands.
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http://dx.doi.org/10.1016/s0379-0738(03)00097-5DOI Listing
June 2003

Y-chromosome STR haplotypes in a southwest Spain population sample.

Forensic Sci Int 2002 Jan;125(1):86-9

Department of Legal Medicine, Faculty of Medicine, University of Cádiz, Fragela s/n, Cádiz 11003, Spain.

The Y-chromosome polymorphism of eight STRs (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392; DYS393, DYS385) were studied in 111 unrelated individuals from the population of southwest Spain. The most common haplotype was shared by 3.6% of the sample, while 99 haplotypes were unique. The gene diversity was 0.9977.
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http://dx.doi.org/10.1016/s0379-0738(01)00613-2DOI Listing
January 2002

Results of the 1999-2000 collaborative exercise and proficiency testing program on mitochondrial DNA of the GEP-ISFG: an inter-laboratory study of the observed variability in the heteroplasmy level of hair from the same donor.

Forensic Sci Int 2002 Jan;125(1):1-7

Departamento de Madrid, Instituto de Toxicología, Sección de Biología, Luis Cabrera 9, 28002 Madrid, Spain.

The Spanish and Portuguese working group (GEP) of international society for forensic genetics (ISFG) 1999-2000 collaborative exercise on mitochondrial DNA (mtDNA) included the analysis of four bloodstain samples and one hair shaft sample by 19 participating laboratories from Spain, Portugal and several Latin-American countries. A wide range of sequence results at position 16,093 of the HV1 (from T or C homoplasmy to different levels of heteroplasmy) were submitted by the different participating laboratories from the hair shaft sample during the first phase of this exercise. During the discussion of these results in the Annual GEP-ISFG 2000 Conference a second phase of this exercise was established with two main objectives: (i) to evaluate the incidence of the HV1 sequence heteroplasmy detected in Phase I across different sample types from the same donor including blood, saliva, and hair shafts, (ii) to perform a technical review of the electropherograms to evaluate the relative levels of heteroplasmies obtained by the different laboratories and also to examine the source of possible errors detected in Phase I. Anonymous review of the raw sequence data permitted the detection of three transcription errors and three errors due to methodological problems. Highly variable levels of heteroplasmy were found in the hair shaft and more stability in blood and saliva. Three laboratories found variable levels of heteroplasmy at position 16,093 across adjacent fragments from the same hair shaft. Two laboratories also described more than one heteroplasmic position from a single hair. The relevance of these findings for the interpretation of mtDNA data in the forensic context is also discussed.
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http://dx.doi.org/10.1016/s0379-0738(01)00602-8DOI Listing
January 2002