Interactions between folate metabolism-related nutrients and polymorphisms on colorectal cancer risk: a case-control study in the Basque country.

Folate-mediated one-carbon metabolism (FOCM) plays an important role in colorectal carcinogenesis. Previous studies have assessed the role of folate-mediated one-carbon metabolism (FOCM)-related gene-diet interaction in the aetiology of colorectal cancer (CRC), however, the results remained inconclusive. Thus, this study aimed to investigate dietary factors and genetic variants related to FOCM, as well as potential nutrient-gene and nutrient-lifestyle interactions, on CRC risk. This observational study included 229 patients diagnosed with CRC and 229 age- and sex-matched subjects as controls from a population-based bowel cancer screening program. Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95%CI) for CRC risk. A Bonferroni-corrected threshold of α = 0.005 was considered significant, and P values less than 0.05 were considered to be suggestive of an association. After Bonferroni correction, a high dietary intake of betaine was associated with a decreased risk of CRC in the adjusted model (OR, 95% CI: 0.21, 0.10-0.40, P < 0.001). Two SNPs, rs1476413 and rs17824591, exhibited significant gene-diet interactions with total choline ad vitamin B12 intakes, respectively, in adjusted models (total choline, tertile 3 vs. 1, OR, 95% CI: 0.25, 0.11-0.66, Pinteraction = 0.012; vitamin B12, tertile 2 vs. tertile 1, OR, 95% CI: 2.48, 1.04-5.00, Pinteraction = 0.003). These findings suggest that betaine intake and interactions between some dietary factors and variants in MTHFR and MTHFD1 genes have an influence on CRC risk in the population studied. If these results are confirmed, specific nutritional intervention strategies could be designed.

Association between nutrient intake related to the one-carbon metabolism and colorectal cancer risk: a case-control study in the Basque Country.

PURPOSE: Epidemiologic evidence for the association between methyl-donor nutrient intake and colorectal cancer (CRC) risk remains inconclusive. We aimed to examine the relationship between intake of vitamins of the B group, methionine, total choline and betaine and CRC risk, in a population from the CRC screening programme in the Basque Country. DESIGN: This observational study included 308 patients with CRC and 308 age- and sex-matched subjects as controls. During recruitment, dietary, anthropometric, lifestyle, socioeconomic, demographic, and health status information was collected. Conditional logistic regression was used to estimate the odds ratios (ORs) for CRC risk. RESULTS: The adjusted ORs for CRC risk decreased with higher intakes of choline and betaine (p < 0.05). After further adjustment for folate, high intake of choline and betaine remained associated with a reduced CRC risk (adjusted model for choline, OR third tertile vs first tertile = 0.45, 95% CI 0.26-0.80, p = 0.006; for betaine, OR third tertile vs first tertile = 0.27, 95% CI 0.16-0.47, p < 0.001). Regarding the other nutrients, our findings indicated a non-significant decrease in CRC risk with the high level of intake. CONCLUSIONS: Our data suggest that choline and betaine intake influence CRC risk in the studied population.

Genetic polymorphisms of 17 X-STR loci in two Tunisian populations from Sousse and Makthar.

BACKGROUND: Tunisia has a complex demographic history of migrations from within Africa, Europe, and the Middle East. However, only one population study based on X-STR markers has been reported so far. AIM: To investigate the genetic polymorphisms of 17 X-STRs in two Tunisian populations from the cities of Sousse and Makthar, and to reveal the genetic relationships with other reference populations. SUBJECTS AND METHODS: A total of 194 unrelated healthy individuals were analysed for 17 X-STR markers. RESULTS: Our results indicate that DXS6809 is the most polymorphic locus, whereas DXS6807 is the least informative marker in the populations of Sousse and Makthar. In addition, forensic statistical parameters, such as the power of discrimination in males and females, as well as the mean of exclusion in duos and trios, reveal that the panel of 17 X-STRs is highly informative and useful in different forensic applications. Overall, pairwise genetic distances (Fst) and non-metric MDS plots demonstrate clustering of different populations according to their geographic locations and their historical relationships. CONCLUSION: Overall, the study of X-STR markers of the Tunisian populations can help to promote the establishment of a forensic DNA reference database in Tunisia and provide reference for future anthropological research.

Study of 17 X-STRs in Native American and Mestizo populations of Central America for forensic and population purposes.

In the present work, an extensive analysis of the X-chromosomal pool of Native American and Mestizo groups of Central America (Guatemala, El Salvador, Nicaragua, and Panama) has been carried out. Allele and haplotype frequency databases, as well as other forensic parameters for these populations, are presented. The admixture analysis supports the tri-hybrid composition in terms of ancestry in the Mestizo populations, with a predominant Native American contribution (54-69%), followed by European (19-28%) and African contributions (12-19%). Pairwise FST genetic distances highlight the genetic proximity between the northernmost Central American populations, especially among admixed populations. The unique and complex nature of this area, where populations from different origins intercrossed, as well as the informativity of X-STR data, highpoint the great interest of this genetic study. Furthermore, the X-chromosome databases for Central American populations here provided will be not only useful for forensic and population purposes not only in the target countries but also in the host countries.

Optical Single Cell Resolution Cytotoxicity Biosensor Based on Single Cell Adhesion Dot Arrays.

Low cost, easy to use cell viability tests are needed in the pharmaceutical, biomaterial, and environmental industries to measure adverse cellular effects. We present a new methodology to track cell death with high resolution. Adherent cells commonly detach from the surface when they die, but some toxic compounds promote cell adhesion. A methodology that enables both dynamic detachment monitoring but also rapid detection of toxic effects of compounds that promote cell adhesion would constitute a step forward toward high-throughput cytotoxicity measurements. We achieved dynamic digital quantification of cell viability by simple optical imaging using "single cell adhesion dot arrays" (SCADA), fibronectin (FN) dot arrays designed to accommodate a single cell on each fibronectin dot. For cytotoxicity measurements, cell-filled SCADA substrates were exposed to K2CrO4, HgSO4 salts, and dimethyl sulfoxide (DMSO). The toxic effect of DMSO and K2CrO4 was dynamically monitored by measuring the cell detachment rate during more than 30 h by quantifying the number of occupied dots in the SCADA array. HgSO4 inhibited cellular detachment from the surface, and cytotoxicity was monitored using the trypan blue life/death assay directly on the surface. In all cases, the cytotoxicity effects were easily monitored with single cell resolution, and the results were comparable to previous reports. SCADA enabled dynamic measurements at the highest resolution due to the digital measuring in this method. The integration of SCADA substrates into microfluidic platforms will provide a practical tool that will extend to fundamental research and commercial applications.

Validation of a 52-mtSNP minisequencing panel for haplogroup classification of forensic DNA samples.

Mitochondrial DNA (mtDNA) is a useful tool in forensic investigation as it provides information about the matrilineal ancestry of individuals. In addition, mtDNA can be analyzed when the analysis of other nuclear markers is underperforming. Recently, we developed a minisequencing panel for the simultaneous analysis of 52 mtDNA SNPs to classify maternal lineages into the main haplogroups and their phylogeographic origin. In order to make this panel suitable for forensic genetics laboratories, a validation study has been performed in accordance with the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines, including species specificity, reproducibility, sensitivity, and stability tests. The results demonstrate that the panel of 52 mtDNA SNPs is highly sensitive, since it enables to obtain complete genetic profiles of samples containing minimal amounts of DNA (1 pg). Furthermore, it provides sufficient genetic information to detect the matrilineal biogeographical origin of highly degraded samples, i.e., ancient dating skeletal remains, and samples with the presence of inhibitors, such as hematin and humic acid. In addition, this panel can detect mixtures in samples whose mtDNA haplogroups of contributors are different. Overall, the results of this study demonstrate the suitability of this minisequencing panel of 52 mtDNA SNPs to be used in forensic cases, with samples of low amount or degraded DNA.

Genetic variation of 17 X-chromosome STR loci in Tunisian population of Nabeul.

In the present study, the genetic variations of 17 X-STR markers (DXS8378, DXS9898, DXS7133, GATA31E08, GATA172D05, DXS6801, DXS7423, DXS6809, DXS6799, DXS7132, DXS9902, DXS6800, DXS6789, DXS10075, DXS10079, DXS6807, and DXS6803) were analyzed in 139 unrelated individuals in Nabeul, aiming to perform an X-STR database for anthropological and forensic purposes. Our results indicate that DXS6809 was the most polymorphic locus, whereas DXS6807 was the least informative marker. In addition, the obtained values for the statistical parameters of forensic interest, i.e., the power of discrimination in males (PDM) and females (PDF), as well as the mean exclusion chance in duos (MECD) and trios (MECT) have demonstrated that this panel of 17 X-STRs is highly informative and useful for forensic application and anthropological research. Additionally, pairwise genetic distances based on FST were calculated between Nabeul population and other populations extracted from the literature. Genetic distances were represented in a non-metric MDS plot and clustering of populations according to their geographic locations and their historical relationship was detected.

Effective resolution of the Y chromosome sublineages of the Iberian haplogroup R1b-DF27 with forensic purposes.

Single-nucleotide polymorphisms (SNPs) found within the non-recombining region of the Y chromosome (NRY) represent a powerful tool in forensic genetics for inferring the paternal ancestry of a vestige and complement the determination of biogeographical origin in combination with other markers like AIMs. In the present study, we introduce a panel of 15 Y-SNPs for a fine-resolution subtyping of the haplogroup R1b-DF27, in a single minisequencing reaction. This is the first minisequencing panel that allows a fine subtyping of R1b-DF27, which displays high frequencies in Iberian and Iberian-influenced populations. This panel includes subhaplogroups of DF27 that display moderate geographical differentiation, of interest to link a sample with a specific location of the Iberian Peninsula or with Iberian ancestry. Conversely, part of the intricacy of a new minisequencing panel is to have all the included variants available to test the effectiveness of the analysis method. We have overcome the absence of the least common variants through site-directed mutagenesis. Overall, the results show that our panel is a robust and effective method for subtyping R1b-DF27 lineages from a minimal amount of DNA, and its high resolution enables to improve male lineage discrimination in Iberian and Southwest European descent individuals. The small length of the amplicons and its reproducibility makes this assay suitable for forensic and population genetics purposes.

Only full adherence to proton pump inhibitors protects against drug-induced upper gastrointestinal bleeding.

PURPOSE: The use of gastroprotective agents has allowed significant progress in the prevention of upper gastrointestinal bleeding (UGIB) associated with non-steroidal anti-inflammatory drugs (NSAIDs) and antiplatelet agents. Nevertheless, some concerns remain regarding the gastroprotective dosage and treatment duration. Our aim was to study the effect of gastroprotective agents in UGIB induced by NSAIDs and single- or dual-antiplatelet therapy. METHODS: A multicenter case-control study was conducted including 577 cases diagnosed with UGIB and 1343 sex-, age-, and hospital-matched controls. To estimate exposure to NSAIDs and gastroprotective agents, consumption was calculated for the 4 weeks prior to hospital admission in terms of defined daily doses (DDDs). Risk groups for UGIB induced by NSAIDs and single- or dual-antiplatelet therapy were defined as a function of each drug dose, use of gastrointestine-damaging drugs, and risk factors for UGIB. Odds ratios (ORs) with 95% confidence intervals (CIs) were adjusted for single- (model 1) and dual- (model 2) antiplatelet therapy. RESULTS: Full adherence (> 0.80DDD) to proton pump inhibitors (PPIs) was the only gastroprotective therapy that significantly reduced the risk of UGIB, considering NSAID risk (OR: 0.53; 95% CI: 0.30-0.95) and dose (OR: 0.48; 95% CI: 0.27-0.87) with ORs adjusted for single-antiplatelet therapy (model 1) and NSAID risk (OR: 0.55; 95% CI: 0.31-0.98) and dose (OR: 0.49; 95% CI: 0.28-0.89) with ORs adjusted for dual-antiplatelet therapy (model 2). CONCLUSIONS: These results reinforce the recommendation of adding a PPI at effective doses (full adherence) to prevent UGIB induced by NSAIDs, or single- or dual-antiplatelet therapy.

Distinct correlations between lipogenic gene expression and fatty acid composition of subcutaneous fat among cattle breeds.

BACKGROUND: The fatty acid (FA) composition of adipose tissue influences the nutritional quality of meat products. The unsaturation level of FAs is determined by fatty acid desaturases such as stearoyl-CoA desaturases (SCDs), which are under control of the transcription factor sterol regulatory element-binding protein (SREBP). Differences in SCD genotype may thus confer variations in lipid metabolism and FA content among cattle breeds. This study investigated correlations between FA composition and lipogenic gene expression levels in the subcutaneous adipose tissue of beef cattle breeds of different gender from the Basque region of northern Spain. Pirenaica is the most important beef cattle breed in northern Spain, while Salers cattle and Holstein-Friesian cull cows are also an integral part of the regional beef supply. RESULTS: Pirenaica heifers showed higher monounsaturated FA (MUFA) and conjugated linoleic acid (CLA) contents in subcutaneous adipose tissue than other breeds (P < 0.001). Alternatively, Salers bulls produced the highest oleic acid content, followed by Pirenaica heifers (P < 0.001). There was substantial variability in SCD gene expression among breeds, consistent with these differences in MUFA and CLA content. Correlations between SCD1 expression and most FA desaturation indexes (DIs) were positive in Salers (P < 0.05) and Pirenaica bulls, while, in general, SCD5 expression showed few significant correlations with DIs. There was a significant linear correlation between SCD1 and SRBEP1 in all breeds, suggesting strong regulation of SCD1 expression by SRBEP1. Pirenaica heifers showed a stronger correlation between SCD1 and SREBP1 than Pirenaica bulls. We also observed a opposite relationship between SCD1 and SCD5 expression levels and opposite associations of isoform expression levels with the ∆9 desaturation indexes. CONCLUSIONS: These results suggest that the relationships between FA composition and lipogenic gene expression are influenced by breed and sex. The opposite relationship between SCD isoforms suggests a compensatory regulation of total SCD activity, while opposite relationships between SCD isoforms and desaturation indexes, specially 9c-14:1 DI, previously reported as an indicator of SCD activity, may reflect distinct activities of SCD1 and SCD5 in regulation of FA content. These findings may be useful for beef/dairy breeding and feeding programs to supply nutritionally favorable products.

17 to 23: A novel complementary mini Y-STR panel to extend the Y-STR databases from 17 to 23 markers for forensic purposes.

A Y-STR multiplex system has been developed with the purpose of complementing the widely used 17 Y-STR haplotyping (AmpFlSTR Y Filer® PCR Amplification kit) routinely employed in forensic and population genetic studies. This new multiplex system includes six additional STR loci (DYS576, DYS481, DYS549, DYS533, DYS570, and DYS643) to reach the 23 Y-STR of the PowerPlex® Y23 System. In addition, this kit includes the DYS456 and DYS385 loci for traceability purposes. Male samples from 625 individuals from ten worldwide populations were genotyped, including three sample sets from populations previously published with the 17 Y-STR system to expand their current data. Validation studies demonstrated good performance of the panel set in terms of concordance, sensitivity, and stability in the presence of inhibitors and artificially degraded DNA. The results obtained for haplotype diversity and discrimination capacity with this multiplex system were considerably high, providing further evidences of the suitability of this novel Y-STR system for forensic purposes. Thus, the use of this multiplex for samples previously genotyped with 17 Y-STRs will be an efficient and low-cost alternative to complete the set of 23 Y-STRs and improve allele databases for population and forensic purposes.

Coregulation and modulation of NFκB-related genes in celiac disease: uncovered aspects of gut mucosal inflammation.

It is known that the NFκB route is constitutively upregulated in celiac disease (CD), an immune-mediated disorder of the gut caused by intolerance to ingested gluten. Our aim was to scrutinize the expression patterns of several of the most biologically relevant components of the NFκB route in intestinal biopsies from active and treated patients and after in vitro gliadin challenge, and to assess normalization of the expression using an inhibitor of the MALT1 paracaspase. The expression of 93 NFκB genes was measured by RT-PCR in a set of uncultured active and treated CD and control biopsies, and in cultured biopsy series challenged with gliadin, the NFκB modulator, both compounds and none. Methylation of eight genes involved in NFκB signaling was analyzed by conventional pyrosequencing. Groups were compared and Pearson's correlation matrixes were constructed to check for coexpression and co-methylation. Our results confirm the upregulation of the NFκB pathway and show that constitutively altered genes usually belong to the core of the pathway and have central roles, whereas genes overexpressed only in active CD are more peripheral. Additionally, this is the first work to detect methylation level changes in celiac intestinal mucosa. Coexpression is very common in controls, whereas gliadin challenge and especially chronic inflammation present in untreated CD result in the disruption of the regulatory equilibrium. In contrast, co-methylation occurs more often in active CD. Importantly, NFκB modulation partially restores coregulation, opening the door to future therapeutic possibilities and targets.

Development of a new highly efficient 17 X-STR multiplex for forensic purposes.

Currently, two of the most widely used X-chromosome STR (X-STR) multiplexes are composed by ten (GHEP-ISFG decaplex) and 12 markers (Investigator Argus X-12 Kit). The number of markers included is a drawback for complex relative testing cases, likewise the large size of some amplicons difficult their application to degraded samples. Here, we present a new multiplex of 17 X-STRs with the aim of increasing both the resolution power and forensic applicability. This newly proposed set includes the X-STRs of the GHEP-ISFG decaplex, four X-STRs from the Investigator Argus X-12 Kit, three of them also included in the decaplex, and six additional more. In order to ensure the allele designation, an allelic ladder was developed. The validation of the present multiplex was carried out according to the revised guidelines by the SWGDAM (Scientific Working Group on DNA Analysis Methods). A total of 488 unrelated individuals from four different continents were analyzed. The forensic efficiency evaluation showed high values of combined power of discrimination in males (≥0.999999996) and females (≥0.999999999999995) as well as combined paternity exclusion probabilities in trios (≥0.99999998) and duos (≥0.999996). The results presented herein have demonstrated that the new 17 X-STR set constitutes a high-resolution alternative to the current X-STR multiplexes.

Nutritional Adequacy and Diet Quality in Colorectal Cancer Patients Postsurgery: A Pilot Study.

Recent evidence has shown that an unhealthy diet is associated with a higher risk of tumor recurrence, metastasis, and death among patients with colorectal cancer (CRC). The aims of this study were to assess nutritional adequacy and diet quality in a group of CRC patients postsurgery and to identify possible associations between dietary and nutritional aspects and environmental factors and weight status. This was an observational study conducted on a random sample of 74 patients, aged 50-69 years. Dietary intake was evaluated utilizing a validated frequency questionnaire, and diet quality was evaluated utilizing the Healthy Eating Index for Spanish Diet and the MedDietScore. Data regarding socioeconomic, demographic, lifestyles, dietary supplements use, and body mass index were collected. Subjects followed a diet characterized by a low carbohydrate intake (94% of the cases), excessive protein (48%), high fat intake (67%), and some micronutrient deficiencies. The inadequacy of some nutrients was associated with male gender, overweight/obesity, smoking, and low educational level; and low adherence to the MedDiet was identified in those with a low educational level (adjusted odds ratio = 4.16, P < 0.05). Therefore, such patients should be an important target group when applying educational programs and giving individualized nutritional advice to improve their quality of life.

Influence of Dopaminergic System Genetic Variation and Lifestyle Factors on Excessive Alcohol Consumption.

AIMS: To examine the role of genetic and environmental factors in the pathogenesis of alcohol dependence in a Spanish cohort of women and men. METHODS: We analyzed the relationship between 56 genetic variants in 7 genes associated with the dopaminergic reward pathway and excessive alcohol consumption. The study sample (N = 1533, of which 746 were women) consisted of 653 heavy consumers and 880 very low consumers from the Spanish subcohort of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Single nucleotide polymorphisms (SNPs) were genotyped using a customized array. Lifestyle variables were also examined to assess associations between genetic and environmental factors. RESULTS: No statistically significant differences were found between cases and controls for the allele frequencies in five genes: TH, SLC18A2, DRD1, DRD3 and COMT. Conversely, some alleles of the 12 SNPs from the DRD2 locus and the 5 from the MAOA locus showed significant associations with excessive alcohol consumption. Namely, rs10891556 (DRD2) proved to be the only SNP positively correlated with excessive alcohol consumption in both sexes. DRD2 rs1800497 and rs877138 were significantly associated in men, whereas DRD2 rs17601612 and rs4936271 and MAOA rs5906898 were associated with excessive alcohol consumption in women. A correspondence analysis provided an overall lifestyle profile of excessive drinkers, who were predominantly men who smoked, had large intakes of meat, small intakes of fruit and vegetables, whose jobs did not require high education levels and who engaged in little physical activity. CONCLUSIONS: It has shown the influence of dopaminergic pathway in the genetics of alcohol dependence with differences between men and women and providing a lifestyle profile of excessive drinkers.

Potential relationship between single nucleotide polymorphisms used in forensic genetics and diseases or other traits in European population.

Single nucleotide polymorphisms (SNPs) are an interesting option to facilitate the analysis of highly degraded DNA by allowing the reduction of the size of the DNA amplicons. The SNPforID 52-plex panel is a clear example of the use of non-coding SNPs in forensic genetics. However, nonstop advances in studies of genetic polymorphisms are leading to the discovery of new associations between SNPs and diseases. The aim of this study was to perform a comprehensive review of the state of association between the 52 SNPs in the 52-plex panel and diseases or other traits related to their treatment, such as drug response characters. In order to achieve this goal, we have conducted a bioinformatic search for each SNP included in the panel and the SNPs in linkage disequilibrium (LD) with them in the European population (r (2) > 0.8). A total of 424 SNPs (52 in the panel and 372 in LD) were investigated in PubMed, Scopus, and dbSNP databases. Our results show that three SNPs in the SNPforID 52-plex panel (rs2107612, rs1979255, rs1463729) have been associated with diseases such as hypertension or macular degeneration, as well as drug response. Similarly, three out of the 372 SNPs in LD (rs2107614, r (2) = 0.859; rs765250, r (2) = 0.858; rs11064560, r (2) = 0,887) are also associated with various pathologies. In view of these results, we propose the need for a periodic review of the SNPs used in forensic genetics in order to keep their associations with diseases or related phenotypes updated and to evaluate their continuity in forensic panels for avoiding legal and ethical conflicts.

Microsatellites' mutation modeling through the analysis of the Y-chromosomal transmission: Results of a GHEP-ISFG collaborative study.

The Spanish and Portuguese Speaking Working Group of the International Society for Forensic Genetics (GHEP-ISFG) organized a collaborative study on mutations of Y-chromosomal short tandem repeats (Y-STRs). New data from 2225 father-son duos and data from 44 previously published reports, corresponding to 25,729 duos, were collected and analyzed. Marker-specific mutation rates were estimated for 33 Y-STRs. Although highly dependent on the analyzed marker, mutations compatible with the gain or loss of a single repeat were 23.2 times more likely than those involving a greater number of repeats. Longer alleles (relatively to the modal one) showed to be nearly twice more mutable than the shorter ones. Within the subset of longer alleles, the loss of repeats showed to be nearly twice more likely than the gain. Conversely, shorter alleles showed a symmetrical trend, with repeat gains being twofold more frequent than reductions. A positive correlation between the paternal age and the mutation rate was observed, strengthening previous findings. The results of a machine learning approach, via logistic regression analyses, allowed the establishment of algebraic formulas for estimating the probability of mutation depending on paternal age and allele length for DYS389I, DYS393 and DYS627. Algebraic formulas could also be established considering only the allele length as predictor for DYS19, DYS389I, DYS389II-I, DYS390, DYS391, DYS393, DYS437, DYS439, DYS449, DYS456, DYS458, DYS460, DYS481, DYS518, DYS533, DYS576, DYS626 and DYS627 loci. For the remaining Y-STRs, a lack of statistical significance was observed, probably as a consequence of the small effective size of the subsets available, a common difficulty in the modeling of rare events as is the case of mutations. The amount of data used in the different analyses varied widely, depending on how the data were reported in the publications analyzed. This shows a regrettable waste of produced data, due to inadequate communication of the results, supporting an urgent need of publication guidelines for mutation studies.

Improving the analysis of Y-SNP haplogroups by a single highly informative 16 SNP multiplex PCR-minisequencing assay.

The SNP haplogroups of the Y-chromosome are nonrandomly distributed among human populations. They are used for tracing the phylogeographical history of paternal lineages of male individuals and can be a useful tool for approaching the patrilineal bio-geographic ancestry of unknown forensic evidences. With the aim of facilitating the inference of the principal informative worldwide Y-SNP haplogroups, we have selected the minimum possible number of key Y-SNPs to be amplified in a sensitive single multiplex PCR and detected by minisequencing. This assay, that includes 16 Y-SNPs, was tested for male human specificity, sensitivity, and reproducibility. Its effectiveness was assessed in a set of degraded DNA samples and in a panel of male individuals from different worldwide populations. All these tests demonstrated the convenience of this assay for assigning the major Y haplogroups to forensic evidences by one single PCR-minisequencing reaction.

Young Alu insertions within the MHC class I region in native American populations: insights into the origin of the MHC-Alu repeats.

OBJECTIVES: Genetic heterogeneity of two Amerindian populations (Jujuy province, Argentina, and Waorani tribe, Ecuador) was characterized by analyzing data on polymorphic Alu insertions within the human major histocompatibility complex (MHC) class I region (6p21.31), which are completely nonexistent in Native Americans. We further evaluated the haplotype distribution and genetic diversity among continental ancestry groups and their potential implications for the dating of the origin of MHC-Alus. METHODS: Five MHC-Alu elements (AluMicB, AluTF, AluHJ, AluHG, and AluHF) were typed in samples from Jujuy (N = 108) and Waorani (N = 36). Allele and haplotype frequency data on worldwide populations were compiled to explore spatial structuring of the MHC-Alu diversity through AMOVA tests. We utilized the median-joining network approach to illustrate the continental distribution of the MHC-Alu haplotypes and their phylogenetic relationships. RESULTS: Allele and haplotype distributions differed significantly between Jujuy and Waorani. The Waorani featured a low average heterozygosity attributable to strong population isolation. Overall, Alu markers showed great genetic heterogeneity both within and among populations. The haplotype distribution was distinctive of each continental ancestry group. Contrary to expectations, Africans showed the lowest MHC-Alu diversity. CONCLUSIONS: Genetic drift mainly associated to population bottlenecks seems to be reflected in the low MHC-Alu diversity of the Amerindians, mainly in Waorani. Geographical structuring of the haplotype distribution supports the efficiency of the MHC-Alu loci as lineage (ancestry) markers. The markedly low Alu diversity of African populations relative to other continental clusters suggests that these MHC-Alus might have arisen after the anatomically modern humans expanded out of Africa.

The Murcia Twin Registry: a population-based registry of adult multiples in Spain.

The Murcia Twin Registry (MTR) was created in 2006, under the auspices of the University of Murcia and the regional Health Authority, aiming to develop a research resource in Spain intended to stimulate current research and new investigation on the analysis of genetic factors related to health and health-related behaviors. The MTR development strategy was designed as a step-by-step process. Initially, it was focused on women's health but nowadays it includes males and opposite-sex twins. The database comprises 2,281 participants born between 1940 and 1966 in the region of Murcia, in Spain. There have been three waves of data collection and today the MTR databases include questionnaire and anthropometric data as well as biological samples. The current main areas of research interest are health and health-related behaviors, including lifestyle, health promotion, and quality of life. Future short-term development points to the completion of the biobank and continuing the collection of longitudinal data.