Search PubMed⌕ Search

Biomedical subjects

A Carracedo

Publications and source records attributed to A Carracedo.

At least 37 records · Page 2Linked to original sources
PubMed2003

Genetic differentiation of the Cabo Verde archipelago population analysed by STR polymorphisms.

Allele frequencies for 17 STR loci were analyzed in a sample of unrelated males from the Cabo Verde Archipelago. The samples were gathered in such a way that the origin of the subjects was perfectly identified, and they could be included in one of the leeward or windward groups of islands. This study reveals that there are significant differences between both groups of islands, and between Cabo Verdeans and other populations from sub-Sahara Africa including the Guineans, the most probable source population for Cabo Verdeans. This study confirms mtDNA data and, together with HLA and Y chromosome data already published, shows that the Cabo Verde population is sub-structured and atypical, diverging substantially from mainland sub-Saharan populations. Overall these differences are most probably due to admixture between sub-Saharan slaves brought into the islands and other settlers of European origin. In the absence of a clear indication of a different ethnic composition of the first sub-Saharan settlers of Cabo Verde, the differentiation exhibited in both groups of islands can be most probably be attributed to genetic drift.

Africa, Western↗
PubMed2003

The three most common CARD15 mutations associated with Crohn's disease and the chromosome 16 susceptibility locus for systemic lupus erythematosus.

OBJECTIVE: To test if the three most common mutations contributing to Crohn's disease on the CARD15/NOD2 gene could contribute also to genetic susceptibility to systemic lupus erythematosus (SLE), which has been found to be linked to the region of chromosome 16q13 where the CARD15 gene is located. METHODS: We obtained DNA samples from the blood of 189 SLE patients (according to the American College of Rheumatology classification criteria) and 194 controls of Spanish ancestry. Genotypes for the three CARD15 mutations (3020insC, 2722G>C and 2104C>T) were determined by hybridization with fluorescence resonance energy transfer probes on a LightCycler real-time polymerase chain reaction system. RESULTS: CARD15 genotypes were similar in SLE patients and in controls from the general population (allelic frequencies for 3020insC 0.013 in SLE patients vs 0.013 in controls; for 2722G > C 0.011 vs 0.008; and for 2104C > T 0.032 vs 0.051). CONCLUSION: We did not find evidence that the Crohn's disease-associated mutations on CARD15 contributed to SLE susceptibility.

Carrier Proteins↗
PubMed2002

Extending STR markers in Y chromosome haplotypes.

Two multiplex reactions were developed to amplify 16 Y-STRs (DYS19, DYS385, DYS389 I and II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, GATA A7.1, GATA A7.2, GATA A10, GATA C4, GATA H4). Here we extend previous population studies done in a sample from northern Portugal for the GATA A7.1, GATA A7.2, GATA C4 and GATA H4 loci. A total of 199 different haplotypes identified by the 16 Y-STR markers were observed in a sample of 208 male individuals, of which 190 were unique and 9 were found twice. The overall haplotype diversity was 0.9996. The haplotype diversity of the Y-STR set composed of the 8 new markers is higher than the Y-STR core set included in the Y-STR haplotype reference database. Sequence structure of new alleles for GATA C4 and GATA H4 is reported. The usefulness of the inclusion of this new set of Y-STRs in forensic casework was also assessed. The increase in haplotype diversity with the addition of any new Y-STR marker to the 8 Y-STR core set is dependent not only on the gene diversity (positively) but also (negatively) on the degree of gametic association between the markers and the haplotypes previously defined. For instance, in our sample the addition of the DYS437, DYS438 and GATA A7.2 to a 13-locus set increased haplotype diversity only by 0.0001.

Base Sequence↗
PubMed2002

Genetic diversity of Y-specific STRs in chimpanzees (Pan troglodytes).

Using the primers described for humans, sequences for 11 Y-specific microsatellites (DYS434, DYS435, DYS436, DYS437, DYS438, DYS439, GATA A10, A7.1, A7.2, C4, and H4 [Gusmão et al., in press]), previously described in 10 male chimpanzees (Pan troglodytes), were confirmed in nine additional male chimpanzees. Sequences for nine additional microsatellites (DYS19, DYS385I and II, DYS389I and II, DYS390, DYS391, DYS392, and DYS393) were determined in all 19 male chimpanzees; homology to human Y-Short Tandem Repeat (STRs) was confirmed by sequencing. Good amplification results were not obtained for DYS19 and DYS385I/II. Two amplicons were obtained for DYS389I/II, but in contrast to humans, the larger fragment was not Y-specific. Moreover, no polymorphism was observed for DYS434, DYS435, or GATA A10. Consequently, these eight STRs were eliminated from further analyses, and haplotype and allele frequencies were estimated for the remaining 12 STRs. A high haplotype diversity value was found (1.000 +/- 0.017), demonstrating the usefulness and informative power of these Y-STRs for future studies on chimpanzee population genetics.

Amino Acid Sequence↗
PubMed2002

Analysis of BRCA1 and BRCA2 in breast and breast/ovarian cancer families shows population substructure in the Iberian peninsula.

An estimated 5-10% of all breast and ovarian cancers are due to an inherited predisposition, representing a rather large number of patients. In Spain 1/13-1/14 women will be diagnosed with breast cancer during their lifetime. Two major breast cancer genes, BRCA1 and BRCA2, have been identified. To date, several hundred pathogenic mutations in these two genes have been published or reported to the Breast Cancer Information Core, BIC database (http://www.nhgri.nih.gov/Intramural_research_Lab transfer/Bic/index.html). In the present study, 30 Spanish breast and breast/ovarian cancer families (29 from Galicia, NW Spain, and 1 from Catalonia, NE Spain) were screened for mutations in the BRCA1 and BRCA2 genes. The analysis of these genes was carried out by SSCP for shorter exons and direct sequencing in the case of longer ones. Mutations were found in 8 of the 30 families studied (26.66%). It is important to note that all mutations were detected within the BRCA1 gene: 330 A>G, 910_913delGTTC, 2121 C>T, 3958_3962delCTCAGinsAGGC, and 5530 T>A. The BRCA1 330 A>G mutation was found in four unrelated families and accounted for 50% of all identified mutations.

Adult↗
PubMed2001

Fluorescent SSCP of overlapping fragments (FSSCP-OF): a highly sensitive method for the screening of mitochondrial DNA variation.

The mtDNA analysis (mtDNA) is increasingly being demanded for forensic purposes due to the fact that many times the use of standard nuclear marker fails to analyze degraded samples (such as bones) and specially for the analysis of hair shafts (a common sample in the crime scene). However, analysis of mtDNA sequencing implies a great lab effort when a high number of samples must be analyzed. The present work introduces a novel and reliable method for the screening of mtDNA variation in the first and second hypervariables (HV1 and HV2) regions which we have denominated fluorescent single strand conformation polymorphism (SSCP) of overlapping fragments (FSSCP-OF). FSSCP-OF is based on the basic theory of SSCP analysis and combines two complementary strategies: the use of PCR amplified overlapping fragments and fluorescent detection technology. The overlap region contains a high percentage (50%) of the d-loop mtDNA variation and for this reason, the probability to detect a polymorphic position by SSCP analysis is clearly increased in comparison to conventional SSCP methods due to the fact that the same polymorphic position is usually placed in a different "relative" position in the two overlapped fragments. The use of multicolor fluorescent technology allows also the multiplex amplification of overlapping fragment and its subsequent analysis in an automatic sequencer. We have analyzed 50 samples of unrelated individuals through the FSSCP-OF technique and we have found that using this methodology the probability to distinguish two samples with different sequences is close to 100%. FSSCP-OF has other important advantages with respect to previous screening methods, such as the automation and standardization of the protocols, which is of special interest for the forensic routine.

Base Sequence↗
PubMed2001

DNA Commission of the International Society of Forensic Genetics: recommendations on forensic analysis using Y-chromosome STRs.

During the past few years, the DNA Commission of the International Society of Forensic Genetics has published a series of documents providing guidelines and recommendations concerning the application of DNA polymorphisms to the problems of human identification. This latest report addresses a relatively new area - namely, Y-chromosome polymorphisms, with particular emphasis on short tandem repeats (STRs). This report addresses nomenclature, use of allelic ladders, population genetics and reporting methods.

Alleles↗
PubMed2001

Rare HRAS1 alleles are a risk factor for the development of brain tumors.

BACKGROUND: The highly polymorphic HRAS1 minisatellite locus, located 1 kilobase downstream from the H-ras1 gene, has been associated with increased susceptibility to a variety of cancers. Microsatellite instability (MI), another molecular abnormality observed in human neoplasms, most likely reflects an increased mutation rate and also is thought to underlie cancer predisposition. The purpose of this study was to investigate the association between rare HRAS1 alleles and brain tumors and to correlate the HRAS1 allelotype with MI and clinicopathologic features. METHODS: Ninety-four patients with primary brain tumors (52 gliomas, 32 meningiomas, and 10 schwannomas) and 109 healthy control individuals were studied. The size of HRAS1 alleles was determined by fluorescent detection in an automated DNA sequencer. The interspersion pattern was assessed by the minisatellite variant repeat-polymerase chain reaction technique. RESULTS: Twenty of 94 (21.28%) patients with brain tumors had at least one rare allele, compared with 13 of 109 (11.92%) in the control population (Fisher exact test; P = 0.0329). The presence of rare alleles was associated with an increased risk of brain tumors (odds ratio, 1.99; 95% confidence interval, 0.93-4.27). The overrepresentation of rare alleles in tumor patients mainly reflects the higher frequency observed in the glioma group (P = 0.0086). The authors did not detect association between the presence of rare HRAS1 alleles and MI in their series. No significant difference in the distribution of these alleles was found when tumors were compared according to other clinicopathologic variables. CONCLUSIONS: The presence of rare HRAS1 alleles is associated with an increased risk for the development of glial neoplasms (OR = 2.72; 95% CI, 1.17-6.32). The lack of association between rare HRAS1 polymorphisms and MI suggests that these two genetic factors are not likely to be expression of the same underlying defect.

Alleles↗
PubMed2001

STR data for the AmpFlSTR profiler plus loci from Macau (China).

Allele frequencies for the nine STRs included in the AmpFlSTR profiler plus kit (D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820) were estimated from a sample of 87 unrelated individuals living in the region of Macau, a territory located in the southeastern coast of China.

Alleles↗
PubMed2001

Sequence structure of 12 novel Y chromosome microsatellites and PCR amplification strategies.

In this work, we present sequencing data for 12 recently reported Y STR loci (DYS434, DYS435, DYS436, DYS437, DYS438, DYS439, GATA A10, GATA 7.1, GATA 7.2, GATA C4, GATA H4, GATA A4), as well as the PCR multiplex strategies we implemented for their detection. Sequenced allelic ladders were constructed and a nomenclature for these new systems is proposed based on the sequence structure and following ISFG recommendations.GATA A4 and DYS439 are likely the same STR. They have the same STR structure and the alleles are always the same in the same individuals.Sequence polymorphisms were observed in the GATA C4 and DYS437 STRs. The variation in DYS437 was associated with a specific population group and is very interesting not only for forensic genetics but also for anthropological studies.

Alleles↗
PubMed2001

Y-chromosome STR haplotypes from a Western Mediterranean population sample.

Nine Y-chromosome STRs were investigated in a male population sample from the Western Mediterranean region of Valencia (Eastern Spain). Complete nine Y-chromosomal STRs haplotypes were obtained in 140 individuals, among which 113 different haplotypes were observed. The most common haplotype was shared by 5% of the sample, while 99 haplotypes were unique. The gene diversity was 0.9892 and the discrimination capacity was 0.8071. Significant population differences were observed with respect to other Iberian populations, such as the Basques and Northern Portugueses.

DNA Fingerprinting↗
PubMed2001

Results of a collaborative study of the EDNAP group regarding the reproducibility and robustness of the Y-chromosome STRs DYS19, DYS389 I and II, DYS390 and DYS393 in a PCR pentaplex format.

A collaborative exercise was carried out by the European DNA Profiling Group (EDNAP) in the frame work of the STADNAP program, i.e. standardization of DNA profiling in Europe, in order to evaluate the performance of a Y-chromosome STR pentaplex, which includes the loci DYS19, DYS389 I and II, DYS390 and DYS393 and to determine whether uniformity of results could be achieved among different European laboratories. Laboratories were asked to analyze the five Y-STRs using singleplex and multiplex conditions in three bloodstains and one mixed stain (95% female and 5% male). All the laboratories reported the same results even for the mixed stain included in the exercise. This demonstrates the reproducibility and robustness of Y-chromosome STR typing even with multiplex formats and proves the usefulness of Y-STR systems for analyzing mixed stains with a male component.A total of 930 male samples from 10 different populations from Europe were also analysed for all the loci included in the pentaplex. Eight of these ten populations also included haplotype data. As for single gene analysis, haplotype diversity was higher in Germany and Italy and lower in Western European countries and Finland. Pairwise haplotype analysis shows the Finnish departure from the rest of the populations and a relatively homogeneity in the other European populations with F(ST) estimates lower than 0.05.UPGMA analysis shows an association of Western European population (Ireland, UK, Portugal and Galicia) on the one hand and central European populations on the other.

Blood Stains↗
PubMed2001

Online reference database of European Y-chromosomal short tandem repeat (STR) haplotypes.

The reference database of highly informative Y-chromosomal short tandem repeat (STR) haplotypes (YHRD), available online at http://ystr.charite.de, represents the largest collection of male-specific genetic profiles currently available for European populations. By September 2000, YHRD contained 4688 9-locus (so-called "minimal") haplotypes, 40% of which have been extended further to include two additional loci. Establishment of YHRD has been facilitated by the joint efforts of 31 forensic and anthropological institutions. All contributing laboratories have agreed to standardize their Y-STR haplotyping protocols and to participate in a quality assurance exercise prior to the inclusion of any data. In view of its collaborative character, and in order to put YHRD to its intended use, viz. the support of forensic caseworkers in their routine decision-making process, the database has been made publicly available via the Internet in February 2000. Online searches for complete or partial Y-STR haplotypes from evidentiary or non-probative material can be performed on a non-commercial basis, and yield observed haplotype counts as well as extrapolated population frequency estimates. In addition, the YHRD website provides information about the quality control test, genotyping protocols, haplotype formats and informativity, population genetic analysis, literature references, and a list of contact addresses of the contributing laboratories.

Databases, Factual↗
PubMed2001

The use of the LightCycler for the detection of Y chromosome SNPs.

A novel methodology based on PCR monitoring on-line with fluorescent formats using the LightCycler for Y chromosome SNP typing is proposed. The main advantages of the system are the time necessary for the analysis (which is around 20 min), the robustness and the accuracy of the method and especially its sensitivity, which permits the detection of the male component in male-female mixtures up to 1:300 for some of the SNPs. Singleplexes of four different SNPs (M9, sY81, SRY-1532 and SRY-2627) as well as two duplexes (M9 and sY81 on the one hand and SRY-1532 and SRY-2627 on the other) were efficiently implemented. A simultaneous amplification and analysis of the four SNPs is also possible. It seems difficult with the current methodology to implement more than a quadruplex.

Alleles↗
PubMed2001

Y-chromosome variation in a Norwegian population sample.

Y-chromosome DNA profiles are promising tools in population genetics and forensic science. Here we present DNA profiles of 300 unrelated Y-chromosomes of Norwegian origin. The profile is composed of eight short tandem repeats (STRs) and one single nucleotide polymorphism (SNP). In more than 2/3 of the haplotypes the modular structure in the 5' end of the minisatellite locus DYF155S1 was revealed by minisatellite variant repeat PCR (MVR-PCR) These haplotypes were also typed for deletions of fragment 50f2C (DYF155S2). Allele distribution and paternity exclusion parameters are given for each marker. The degree of haplotype diversity and its implication for statistics are evaluated. In the 300 samples 177 different haplotypes were encountered, of which 137 were observed once only. Analysis showed that the main source of variation is within the population. The Fst values were less than 0.015 in general. Haplotype grouping by the SNP demonstrated two haplogroups (Tat/T and Tat/C). Haplogroup Tat/C--found in 5.7% of the present material - is the same haplogroup as encountered in 60% of Finnish males [Am. J. Hum. Genet. 62 (1998) 1171]. Mutation analysis in 150 father/son pairs (a total of 1200 meiotic events) revealed an average mutation frequency of 0.0042 (95% CI 0.0014-0.0097).

Alleles↗