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A Carracedo

Publications and source records attributed to A Carracedo.

At least 19 recordsLinked to original sources
PubMed1999

Population data on the D1S1656 and D12S391 STR loci in Andalusia (south Spain) and the maghreb (north Africa).

Allele and genotype frequencies for two tetrameric short tandem repeat (STR) loci were determined in two population samples, from Andalusia (S Spain; n = 127) and the Maghreb (N Africa; n = 40). After denaturing polyacrylamide gel electrophoresis, 14 alleles were identified for D12S391 and 13 alleles for D1S1656. No deviations from the Hardy-Weinberg equilibrium were detected. Some statistical parameters of forensic interest (H, PD, EC) were also calculated, and the data obtained for both populations were compared. Sequencing data of several intermediate D12S391 alleles designated 17.3, 18.3, and 19.3 are also presented.

Africa, Northern↗
PubMed1999

Population distribution of six PCR-amplified loci in Madeira Archipelago (Portugal).

Frequency data of the short tandem repeat (STR) loci HUMTH01, HUMVWA31/A, HUMF13A1, HUMFES/FPS, D12S391 and HUMFIBRA/FGA were determined in blood stains obtained from a population of unrelated individuals from the Madeira Archipelago. The observed genotype distribution showed no significant deviation from the Hardy-Weinberg equilibrium and there was no evidence for association of alleles among the six loci. Population data showed a combined discrimination power of 0.9999998 and a chance of exclusion of 0.99597. The frequencies are similar to those of other compared caucasian populations but significant differences were found between the Madeira population and Japanese, Chinese, Greenland Eskimos and Quechua Amerindians. The six loci studied, together proved to be highly discriminating and valuable for forensic cases.

Blood Stains↗
PubMed1999

Genetic data on three complex STRs (ACTBP2, D21S11 and HUMFIBRA/FGA) in the Galician population (NW Spain).

The allele frequency distributions of three complex STRs, ACTBP2 (SE33), D21S11 and HUMFIBRA/ FGA in the population of Galicia were investigated. Analysis was carried out under denaturing conditions and fluorescent detection in the ALF DNA sequencer and typing was made by comparison with sequenced allelic ladders. No significant deviations from Hardy-Weinberg equilibrium were observed. No significant differences were found between our data and other Caucasian population data. ACTBP2 seems to be one of the most informative and polymorphic STRs.

Actins↗
PubMed1999

Definition of a region of loss of heterozygosity at chromosome 11q in cervical carcinoma.

Chromosomal deletions at segment 11q23-q24 have been identified in a variety of human epithelial tumors, including cervical carcinoma (CC), indicating the presence in this region of at least a tumor suppressor gene (TSG) involved in the development of these neoplasms. To localize the 11q deletion target more precisely, 54 primary cervical carcinomas were examined for loss of heterozygosity (LOH) using a panel of microsatellite DNA markers mapping to 11p.15 and spanning region 11q23-qter. Nineteen tumors were found to have LOH at chromosome 11q. The highest frequency of LOH was observed at locus APOC-3, located in 11q23.1-q23.2, which was deleted in 42% of the informative cases. In contrast, LOH was infrequent at distal 11q in current series of CC. The smallest common region of loss included APOC-3 and was defined distally by marker D11S925 in region 11q23. The present data strongly suggest that the 11q suppressor gene(s) involved in cervical tumorigenesis is likely to be located at chromosome region 11q22-q23.

Adenocarcinoma↗
PubMed1999

Population study of HUMTH01, HUMVWA31/A, HUMF13A1, and HUMFES/FPS systems in Azores.

The tetrameric short tandem repeat polymorphisms HUMTH01, HUMVWA31/A, HUMF13A1, and HUMFES/FPS were studied in blood stains obtained from a population of unrelated individuals from the Azores Archipelago (Portugal). Gene frequencies were determined and no deviation from the Hardy-Weinberg equilibrium was found. However, the allelic independence test between loci showed linkage disequilibrium between HUMVWA31/A and HUMFES/FPS. A combined discrimination power and chance of exclusion of, respectively, 0.9999 and 0.9534, reveal the high forensic interest of the four systems. No differences with other caucasoid populations were found, but comparison with some asiatic, eskimo, and amerindian populations showed significant statistical differences.

Amino Acid Sequence↗
PubMed1998

Reproducibility of mtDNA analysis between laboratories: a report of the European DNA Profiling Group (EDNAP).

The aim of this collaborative exercise was to determine whether uniformity of mtDNA sequencing results could be achieved among different EDNAP laboratories. Laboratories were asked to sequence mtDNAHV1 region (16024-16365) from three bloodstains, proceeding in accordance with the protocol and strategies currently used in each individual laboratory. Cycle sequencing was used by 11 laboratories and solid phase single stranded sequencing was used by one laboratory. Different PCR strategies and PCR conditions were used by the different laboratories. Three laboratories used semi-nested PCR, two nested PCR, three direct amplification of HV1 and four amplification of overlapping fragments covering the HV1 region. Despite the diversity of methodologies used, all the laboratories reported the same results. The successful result of this exercise shows that PCR based mtDNA typing by automated sequencing is a valid, robust and reliable means of forensic identification despite the different strategies and methodologies used by the different laboratories.

DNA Fingerprinting↗
PubMed1998

Band shift analysis of three base-pair repeat alleles in the short tandem repeat locus D12S391.

Two hundred and sixty UK Caucasian individuals have been typed for the STR locus D12S391. Measurements of absolute band shift, relative to an allelic ladder, allowed fragments differing by one base pair to be consistently distinguished. The intermediate alleles typed from such fragments comprised approximately 5% of the total alleles observed in this study. The existence of intermediate alleles in the D12S391 locus, not included in the allelic ladder, allowed us to assess the efficacy of band shift analysis in detecting intermediate alleles on two different automated fluorescent detection platforms. The results of sequencing a sample of intermediate alleles are also presented.

Alleles↗
PubMed1998

Normal and anomalous electrophoretic behavior of polymerase chain reaction-based DNA polymorphisms in polyacrylamide gels.

The electrophoretic mobility of five single tandem repeats (STRs) and four amplified fragment length polymorphisms (AFLPs) in polyacrylamide gels was tested under denaturing and nondenaturing conditions. Relative anomalous mobility in nondenaturing conditions was found in one AT-rich AFLP (3'ApoB) and in two AT-rich STRs (HUMACTBP2 and HUMF13A1). In these cases, highly anomalous electrophoretic behavior was found even when changes were made in the %T value alone. In such cases typing results were affected by the gel composition. The mobility of these systems was nevertheless normal under denaturing conditions. As a consequence of this study, we recommended that the typing of these systems should only be performed under denaturing conditions and we also recommend the further study of the electrophoretic behavior of repetitive DNA polymorphisms, especially AT-rich systems, before they are used in forensic or genetic applications.

Acrylic Resins↗
PubMed1998

Minisatellite variant repeat (MVR) analysis of the HRAS1 minisatellite locus.

Two alternative electrophoretic strategies were used to study the internal variation of the HRAS1 minisatellite after minisatellite variant repeat mapping (MVR-PCR) was carried out. While the use of automated sequencers with fluorescent based technology is ideal for analyzing fragment size, and therefore, for analyzing the repeat number, the use of polyacrylamide gels and silver staining is more appropriate for the analysis of internal variation. Thirteen different fragments ranging from 27 to 80 repeats were found in a sample from 80 healthy Caucasian individuals. By using MVR mapping we were able to detect heterozygotes which appear as homozygotes when fragment length analysis was used. As a result of this, the 13 alleles, which we had detected, increased to 16 alleles when MVR sequences were analyzed. The extremely conservative arrays of repeats allow us to infer the theoretical origin of rare alleles from a major group of specific alleles. The HRAS1 minisatellite has been extensively studied due to its association with cancer. However, the methodology used up to now has limited the scope of previous research. Our approach permits the identification of alleles in a fast and reliable way using their MVR codes, thus allowing association studies with cancer.

3' Untranslated Regions↗
PubMed1998

Population genetics of the D12S391, CSF1P0 and TPOX loci in Catalonia (Northeast Spain).

Allele and genotype frequencies for three short tandem repeat loci were determined in a population sample from Catalonia (NE Spain). After denaturing PAGE electrophoresis, 11 alleles were identified for D12S391 (n = 167), 9 alleles for CSF1pO (n = 282) and 6 alleles for TPOX (n = 283). No deviation from Hardy-Weinberg equilibrium was found. The allele frequencies observed are similar to those of other compared European populations.

Alleles↗
PubMed1998

Sequence variation of a hypervariable short tandem repeat at the D1S1656 locus.

A short tandem repeat at the D1S1656 locus was sequenced in 45 selected alleles and 13 different alleles were found which were designated according to the total number of repeats. This STR is a compound hypervariable STR consisting of blocks of (TAGR) repeats with a basic sequence structure (TAGA)4(TGA)0-1(TAGA)6-16(TAGG)0-1(TG)5. The presence of a TGA, probably due to an A deletion in the fifth TAGA repeat leads to intermediate a.3 alleles. Population data showed that this is a highly polymorphic STR with a heterozygosity of more than 0.89. This fact together with its simple structure and small size (129-168 bp) makes this STR one of the most interesting DNA polymorphisms for forensic and genetic purposes.

Alleles↗
PubMed1998

Sequence variation of a variable short tandem repeat at the D18S535 locus.

A short tandem repeat in the D18S535 locus was sequenced in 25 selected alleles. A total of 8 different alleles were found which can be designated according to the total number of repeats. This STR is a simple hypervariable STR consisting of blocks of (GATA) repeats with a basic sequence structure (GATA)1(GACA)1(GATA)1 (GAT)1(GATA)9-16. Population data showed that this is a highly polymorphic STR with a heterozygosity of more than 0.80, a simple structure and small size (130-158 bp) which makes this an interesting DNA polymorphism for forensic and genetic purposes.

DNA↗
PubMed1998

Y chromosome STR haplotypes: genetic and sequencing data of the Galician population (NW Spain).

Recently described Y-STR polymorphisms can be analysed as informative haplotypes which are useful in the forensic field. In order to include these systems in our forensic routine, we have carried out a population study in Galicia (NW Spain) analysing seven Y-STR polymorphisms (DYS19, DYS389-I, DYS389-II, DYS390, DYS393 and DYS385: two loci). The results were compared with other population studies. In addition various alleles for each system (except DYS385) were sequenced and the corresponding allelic ladders constructed.

Genetics, Population↗
PubMed1998

Catalonian population study of the tetranucleotide repeat loci D3S1358, D8S1179, D18S51 and D19S253.

Allele frequencies for four short tandem repeat loci were determined in a population sample from Catalonia (NE Spain). After denaturing PAGE electrophoresis, 8 alleles were identified for D3S1358 (n=201), 10 alleles for D8S1179 (n=198), 13 alleles for D18S51 (n=197) and 11 alleles for D19S253 (n=201). No deviation from Hardy-Weinberg equilibrium was found. Complete and relative uniformity in Caucasoid populations has been observed for D18S51 and D8S1179 respectively. Pronounced differences were found between different ethnic groups for both systems. Catalonia and Portugal do not differ for D3S1358 locus. Multiplex PCR amplifications of three loci (D3S1358, D18S51 and D19S253) without overlapping fragment size ranges could be interesting for monochrome automated laser fluorescence devices.

Alleles↗
PubMed1998

Progress in methodology and standards in European molecular genetics laboratories.

The enormous expansion in the application of the technologies of molecular and cell biology with the objective of resolving medical problems is discussed, as well as the problems arising due to this revolution. Progress in methodology is also reported paying special attention to chip technology. The different types of chips, strategies for readout, and applications are described. The difficulties in achieving common standards in Molecular Genetics are analysed as well as the need to develop European networks of genetic testing laboratories. Forensic genetics is a particular field where the progress in technical and procedural standards has been considerable in European labs. Molecular genetic laboratories with other medical applications could benefit from the progress in standards in the forensic field.

Europe↗
PubMed1998

Low incidence of microsatellite instability in patients with cervical carcinomas.

Alterations in microsatellite sequences have been reported in a variety of human cancers. Microsatellite instability is thought to reflect the inactivation of genes involved in DNA mismatch repair (MMR), which could predispose to the accumulation of further genetic errors in affected cells. Genomic instability in human cancers might also result from the inactivation of cell cycle controls such as the p53-dependent G1 checkpoint that prevents cell replication in response to DNA damage. High-risk human papillomavirus (HPV) is thought to contribute to the development of HPV-associated cancers, including cervical carcinoma, through the interaction of the E6 and E7 viral oncoproteins with two major cell cycle regulatory proteins, namely p53 and the retinoblastoma gene product (pRb). Although the high-risk HPV is prevalent in cervical carcinomas, viral DNA is not detected in a minor proportion of the cases. The HPV infection is insufficient for the development of cervical cancer, which indicates that additional genetic events are involved in the process. This study reports the potential role of MMR gene defects (in addition to or independent of HPV infection) in patients with cervical carcinogenesis. Microsatellite instability and HPV status were analyzed in a series of 54 patients with cervical carcinomas and in two associated cell lines. Microsatellite alterations were examined at 10 loci located in different chromosomes by using semiautomated fluorescent DNA technology and polymerase chain reaction. The HPV types were detected by a general primer polymerase chain reaction method. The results indicate that microsatellite instability is very infrequent in cervical carcinoma and occurs independently of HPV status.

Adenocarcinoma↗
PubMed1998

Linkage analysis in a large Spanish family with X-linked retinitis pigmentosa: phenotype-genotype correlation.

X-linked retinitis pigmentosa (XLRP) accounts for 10-25% of RP families and causes the most severe form of the disease in terms of onset and progression. Although three different loci (RP3, RP2 and RP15) have been proposed on the short arm of the X-chromosome by linkage analysis, RP3 represents the disease locus in the majority of XLRP families. The identification of female carriers of X-linked RP is important for genetic counselling. The presence of fundus and electroretinogram (ERG) abnormalities have been reported to be as high as 87 and 90%, respectively. However, in clinical practice it has not always been possible to know the carrier state of females at risk. Thirty-five members of a Spanish family with X-linked RP were evaluated by linkage analysis using nine polymorphic markers (CYBB, DXS1110, M6, DXS6679, DXS1068, DXS1058, MAOA, MAOB and DXS6849) that map to the X-chromosome region Xp21.1 to Xp11.3, in an attempt to determine the carrier state of these females at risk. It was possible to establish that a RP3 mutation is, most likely, segregating in this family.

Adolescent↗