Effects of Mediterranean diet during pregnancy on the onset of overweight or obesity in the offspring: a randomized trial.

BACKGROUND/OBJECTIVES: The PREMEDI study was designed to assess the efficacy of nutritional counseling aimed at promoting Mediterranean Diet (MD) during pregnancy on the incidence of overweight or obesity at 24 months in the offspring. METHODS: PREMEDI was a parallel-arm randomized-controlled trial. 104 women in their first trimester of pregnancy were randomly assigned in a 1:1 ratio to standard obstetrical and gynecological care alone (CT) or with nutritional counseling promoting MD. Women enrolled in the MD arm were provided with 3 sessions of nutritional counseling (one session per trimester). The main outcome was the proportion of overweight or obesity among the offspring at the age of 24 months. Maternal MD-adherence and weight gain during pregnancy were also evaluated. Lastly, the evaluation of epigenetic modulation of metabolic pathways in the offspring was analyzed in cord blood. RESULTS: Five women in the MD arm and 2 in the CT arm were lost to follow-up, so a total of 97 completed the study. At 24 months, children of MD mothers were less likely to have overweight or obesity than those of the CT mothers (6% vs. 33%, absolute risk difference = -27%, 95% CI -41% to -12%, p < 0.001; number needed to treat 3, 95% CI 2 to 8, intention to treat analysis). A significantly higher increase of MD-adherence during the trial was observed in the MD arm compared to the CT arm. A similar body weight gain at the end of pregnancy was observed in the two arms. The mean (SD) methylation rate of the leptin gene in cord blood was 30.4 (1.02) % and 16.9 (2.99) % in the CT and MD mothers, respectively (p < 0.0001). CONCLUSIONS: MD during pregnancy could be an effective strategy for preventing pediatric overweight or obesity at 24 months. This effect involves, at least in part, an epigenetic modification of leptin expression.

Age affects drug survival rates of interleukin (IL)-17 and IL-23 inhibitors in patients with plaque psoriasis: Results from a retrospective, multicentric, multi-country, cohort study.

BACKGROUND: Scarce data related to the drug survival of biologic agents in psoriasis patients aged ≥65 years is available. OBJECTIVES: To evaluate the drug survival of interleukin (IL)-23 or the IL-17 inhibitors approved for the treatment of moderate-to-severe psoriasis in elderly patients (aged ≥65 years), compared with younger adult patients (aged <65 years), and to identify clinical predictors that can influence the drug survival. METHODS: This retrospective multicentric cohort study included adult patients with moderate-to-severe psoriasis, dissecting two-patient subcohorts based on age: elderly versus younger adults. Kaplan-Meier estimator and proportional hazard Cox regression models were used for drug survival analysis. RESULTS: We included 4178 patients and 4866 treatment courses; 934 were elderly (1072 treatment courses), and 3244 were younger patients (3794 treatment courses). Drug survival, considering all causes of interruption, was higher in patients aged <65 years than in elderly patients overall (log-rank p < 0.006). This difference was significant for treatment courses involving IL-23 inhibitors (p < 0.001) but not for those with IL-17 inhibitors (p = 0.2). According to both uni- and multi-variable models, elder age was associated with an increased risk of treatment discontinuation (univariable analysis: HR: 1.229, 95% CI 1.062-1.422; p < 0.006; multivariable analysis: HR: 1.199, 95% CI 1.010-1.422; p = 0.0377). Anti-IL-23 agents were associated with a reduced likelihood of treatment discontinuation after adjusting for other variables (HR: 0.520, 95% CI 0.368-0.735; p < 0.001). Being previously treated with IL-17 inhibitors increased the probability of discontinuation. CONCLUSIONS: Elderly patients with psoriasis have an increased risk of biologic treatment discontinuation compared with younger adult patients, particularly, if being treated with IL-23 inhibitors. However, in stratified analyses conducted in elderly patients, IL-23 inhibitors showed higher drug survival rates than IL-17 inhibitors.

Cerebrospinal Fluid and Peripheral Blood Lymphomonocyte Single-Cell Transcriptomics in a Subject with Multiple Sclerosis Acutely Infected with HIV.

Signatures of neurodegeneration in clinical samples from a subject with multiple sclerosis (MS) acutely infected with HIV were investigated with single-cell transcriptomics using 10X Chromium technology. Sequencing was carried out on NovaSeq-TM, and the analysis was performed with Cell Ranger software (v 7.1.0) associated with a specifically established bioinformatic pipeline. A total of 1446 single-cell transcriptomes in cerebrospinal fluid (CSF) and 4647 in peripheral blood mononuclear cells (PBMCs) were obtained. In the CSF, many T-cell lymphocytes with an enriched amount of plasma cells and plasmacytoid dendritic (pDC) cells, as compared to the PBMCs, were detected. An unsupervised cluster analysis, putting together our patient transcriptomes with those of a publicly available MS scRNA-seq dataset, showed up-regulated microglial neurodegenerative gene expression in four clusters, two of which included our subject's transcriptomes. A few HIV-1 transcripts were found only in the CD4 central memory T-cells of the CSF compartment, mapping to the gag-pol, vpu, and env regions. Our data, which describe the signs of neurodegenerative gene expression in a very peculiar clinical situation, did not distinguish the cause between multiple sclerosis and HIV infection, but they can give a glimpse of the high degree of resolution that may be obtained by the single-cell transcriptomic approach.

[Treatment of childhood psoriasis: present and future]. / Thérapie du psoriasis pédiatrique : présent et futur.

Psoriasis may present in childhood with skin, nail and scalp lesions but sometimes also articular involvement. It has an import impact on the quality of life of young patients. In this article we present an overview of the treatments that may be used in children according to skin area involved and severity of lesions with special interest for the biological treatments, already available and under investigation.

Le psoriasis peut déjà se manifester dans l'enfance avec des lésions cutanées, des ongles, du scalp, mais parfois aussi une atteinte articulaire. Cette maladie a un impact important sur la qualité de vie de l'enfant. Dans cet article, nous présentons une revue des traitements en ce moment possibles chez les enfants, selon la surface de peau atteinte, la sévérité des lésions, en mettant surtout en lumière les traitements par biologiques déjà possibles et en étude.

Effect of Hyaluronic Acid and Mesenchymal Stem Cells Secretome Combination in Promoting Alveolar Regeneration.

Pharmacological therapies in lung diseases are nowadays useful in reducing the symptomatology of lung injury. However, they have not yet been translated to effective treatment options able to restore the lung tissue damage. Cell-therapy based on Mesenchymal Stem Cells (MSCs) is an attractive, as well as new therapeutic approach, although some limitations can be ascribed for therapeutic use, such as tumorigenicity and immune rejection. However, MSCs have the capacity to secrete multiple paracrine factors, namely secretome, capable of regulating endothelial and epithelial permeability, decrease inflammation, enhancing tissue repair, and inhibiting bacterial growth. Furthermore, Hyaluronic acid (HA) has been demonstrated to have particularly efficacy in promoting the differentiation of MSCs in Alveolar type II (ATII) cells. In this frame, the combination of HA and secretome to achieve the lung tissue regeneration has been investigated for the first time in this work. Overall results showed how the combination of HA (low and medium molecular weight HA) plus secretome could enhance MSCs differentiation in ATII cells (SPC marker expression of about 5 ng/mL) compared to the only HA or secretome solutions alone (SPC about 3 ng/mL, respectively). Likewise, cell viability and cell rate of migration were reported to be improved for HA and secretome blends, indicating an interesting potentiality of such systems for lung tissue repair. Moreover, an anti-inflammatory profile has been revealed when dealing with HA and secretome mixtures. Therefore, these promising results can allow important advance in the accomplishment of the future therapeutic approach in respiratory diseases, up to date still missing.

COVID19 Disease Map, a computational knowledge repository of virus-host interaction mechanisms.

We need to effectively combine the knowledge from surging literature with complex datasets to propose mechanistic models of SARS-CoV-2 infection, improving data interpretation and predicting key targets of intervention. Here, we describe a large-scale community effort to build an open access, interoperable and computable repository of COVID-19 molecular mechanisms. The COVID-19 Disease Map (C19DMap) is a graphical, interactive representation of disease-relevant molecular mechanisms linking many knowledge sources. Notably, it is a computational resource for graph-based analyses and disease modelling. To this end, we established a framework of tools, platforms and guidelines necessary for a multifaceted community of biocurators, domain experts, bioinformaticians and computational biologists. The diagrams of the C19DMap, curated from the literature, are integrated with relevant interaction and text mining databases. We demonstrate the application of network analysis and modelling approaches by concrete examples to highlight new testable hypotheses. This framework helps to find signatures of SARS-CoV-2 predisposition, treatment response or prioritisation of drug candidates. Such an approach may help deal with new waves of COVID-19 or similar pandemics in the long-term perspective.

Detection of recombinant breakpoint in the genome of human enterovirus E11 strain associated with a fatal nosocomial outbreak.

BACKGROUND: The aim of this study was to characterize the genome of a recombinant Enterovirus associated with severe and fatal nosocomial infection; it was typed as Echovirus 11 (E-11) according to the VP1 gene. Enterovirus infection is generally asymptomatic and self-limited, but occasionally it may progress to a more severe clinical manifestation, as in the case described here. Recombination plays a crucial role in the evolution of Enteroviruses (EVs) and has been recognized as the main driving force behind the emergence of epidemic strains associated with severe infection. Therefore, it is of utmost importance to monitor the circulation of recombinant strains for surveillance purposes. METHODS: Enterovirus-RNA was detected in the serum and liver biopsy of patients involved in the nosocomial cluster by commercial One-Step qRT-PCR method and the Enterovirus strains were isolated in vitro. The EVs typing was determined by analyzing the partial-length of the 5'UTR and VP1 sequences with the web-based open-access Enterovirus Genotyping Tool Version 0.1. The amplicons targeting 5'UTR, VP1 and overlapping fragments of the entire genome were sequenced with the Sanger method. Phylogenetic analysis was performed comparing the VP1 and the full-genome sequences of our strains against an appropriate reference set of Enterovirus prototypes of the Picornaviridae genera and species retrieved from the Enterovirus Genotyping Tool. Recombination analysis was performed using RDP4 software. RESULTS: The Neighbor-Joining tree of the VP1 gene revealed that the 4 patients were infected with an identical molecular variant of Echovirus 11 (E-11). While the phylogenetic and the RDP4 analysis of the full-genome sequences provided evidence that it was a chimeric strain between an E-11 and a Coxsackievirus B (CV-B). CONCLUSIONS: The chimeric structure of the E-11 genome might have contributed to the severe infection and epidemic feature of the strain, but further biological characterizations are needed. The evidence reported in this study, highlights the limit of typing techniques based on the VP1 gene, as they fail to identify the emergence of recombinant strains with potentially more pathogenic or epidemic properties, thus providing only partial information on the epidemiology and pathogenesis of Enteroviruses.

Secukinumab Drug Survival in Psoriasis and Psoriatic Arthritis Patients: A 24-Month Real-Life Study.

BACKGROUND: Secukinumab effectiveness has been demonstrated in both psoriasis (PsO) and psoriatic arthritis (PsA). However, it is unknown whether patients with arthritis may carry a risk factor for withdrawal. OBJECTIVE: To identify predictors of secukinumab survival, including the presence of arthritis, in PsO and PsA. METHODS: Consecutive PsO and PsA patients initiating secukinumab were enrolled and followed up every 6 months, up to 24 months or discontinuation. Medical history, disease activity indices and body mass index (BMI) were collected. Kaplan-Meier curves and log-rank test were used to analyze differences in drug survival according to sex, BMI, biological therapy line in the whole population (psoriatic disease), and separately for PsO/PsA. A multivariable Cox regression model was built to assess whether presence of arthritis (main independent variable) may influence drug survival by having time to secukinumab discontinuation as outcome. Results were expressed as hazard ratio and 95% confidence interval. RESULTS: Sixty-two PsO and 90 PsA patients were enrolled. Retention rate at 12 and 24 months, respectively, was 85% and 61% for PsO and 68% and 57% for PsA. In the whole population, naïve patients had a higher chance of drug survival (log-rank = 4.06; p = 0.04); in PsA, obese patients had a significantly higher chance to discontinue secukinumab (log-rank = 5.25; p = 0.021). The multivariable Cox regression showed that arthritis was independently associated with a higher risk of secukinumab discontinuation (hazard ratio 2.43; 95% confidence interval 1.06-5.55, p = 0.035) after adjusting for age, sex, gender, BMI, therapy line and PsO severity at baseline. CONCLUSIONS: Our data confirmed a very good response to secukinumab in both PsO and PsA patients. However, presence of arthritis might affect drug survival.

Psoriasis and Cardiometabolic Diseases: Shared Genetic and Molecular Pathways.

A convincing deal of evidence supports the fact that severe psoriasis is associated with cardiovascular diseases. However, the precise underlying mechanisms linking psoriasis and cardiovascular diseases are not well defined. Psoriasis shares common pathophysiologic mechanisms with atherosclerosis and cardiovascular (CV) risk factors. In particular, polymorphism in the IL-23R and IL-23 genes, as well as other genes involved in lipid and fatty-acid metabolism, renin-angiotensin system and endothelial function, have been described in patients with psoriasis and with cardiovascular risk factors. Moreover, systemic inflammation in patients with psoriasis, including elevated serum proinflammatory cytokines (e.g., TNF-α, IL-17, and IL-23) may contribute to an increased risk of atherosclerosis, hypertension, alteration of serum lipid composition, and insulin resistance. The nonlinear and intricate interplay among various factors, impacting the molecular pathways in different cell types, probably contributes to the development of psoriasis and cardiovascular disease (CVD). Future research should, therefore, aim to fully unravel shared and differential molecular pathways underpinning the association between psoriasis and CVD.

Multi-omics approach to COVID-19: a domain-based literature review.

BACKGROUND: Omics data, driven by rapid advances in laboratory techniques, have been generated very quickly during the COVID-19 pandemic. Our aim is to use omics data to highlight the involvement of specific pathways, as well as that of cell types and organs, in the pathophysiology of COVID-19, and to highlight their links with clinical phenotypes of SARS-CoV-2 infection. METHODS: The analysis was based on the domain model, where for domain it is intended a conceptual repository, useful to summarize multiple biological pathways involved at different levels. The relevant domains considered in the analysis were: virus, pathways and phenotypes. An interdisciplinary expert working group was defined for each domain, to carry out an independent literature scoping review. RESULTS: The analysis revealed that dysregulated pathways of innate immune responses, (i.e., complement activation, inflammatory responses, neutrophil activation and degranulation, platelet degranulation) can affect COVID-19 progression and outcomes. These results are consistent with several clinical studies. CONCLUSIONS: Multi-omics approach may help to further investigate unknown aspects of the disease. However, the disease mechanisms are too complex to be explained by a single molecular signature and it is necessary to consider an integrated approach to identify hallmarks of severity.

Butyrate as a bioactive human milk protective component against food allergy.

BACKGROUND: Food allergy (FA) is a growing health problem worldwide. Effective strategies are advocated to limit the disease burden. Human milk (HM) could be considered as a protective factor against FA, but its mechanisms remain unclear. Butyrate is a gut microbiota-derived metabolite able to exert several immunomodulatory functions. We aimed to define the butyrate concentration in HM, and to see whether the butyrate concentration detected in HM is able to modulate the mechanisms of immune tolerance. METHODS: HM butyrate concentration from 109 healthy women was assessed by GS-MS. The effect of HM butyrate on tolerogenic mechanisms was assessed in in vivo and in vitro models. RESULTS: The median butyrate concentration in mature HM was 0.75 mM. This butyrate concentration was responsible for the maximum modulatory effects observed in all experimental models evaluated in this study. Data from mouse model show that in basal condition, butyrate up-regulated the expression of several biomarkers of gut barrier integrity, and of tolerogenic cytokines. Pretreatment with butyrate significantly reduced allergic response in three animal models of FA, with a stimulation of tolerogenic cytokines, inhibition of Th2 cytokines production and a modulation of oxidative stress. Data from human cell models show that butyrate stimulated human beta defensin-3, mucus components and tight junctions expression in human enterocytes, and IL-10, IFN-γ and FoxP3 expression through epigenetic mechanisms in PBMCs from FA children. Furthermore, it promoted the precursors of M2 macrophages, DCs and regulatory T cells. CONCLUSION: The study's findings suggest the importance of butyrate as a pivotal HM compound able to protect against FA.

SARS-CoV-2 Phylogenetic Analysis, Lazio Region, Italy, February-March 2020.

We report phylogenetic and mutational analysis of severe acute respiratory syndrome coronavirus 2 virus strains from the Lazio region of Italy and provide information about the dynamics of virus spread. Data suggest effective containment of clade V strains, but subsequently, multiple waves of clade G strains were circulating widely in Europe.

miR-622 is a novel potential biomarker of breast carcinoma and impairs motility of breast cancer cells through targeting NUAK1 kinase.

BACKGROUND: Aberrant expression of microRNAs (miR) has been proposed as non-invasive biomarkers for breast cancers. The aim of this study was to analyse the miR-622 level in the plasma and in tissues of breast cancer patients and to explore the role of miR-622 and its target, the NUAK1 kinase, in this context. METHODS: miR-622 expression was analysed in plasma and in tissues samples of breast cancer patients by q-RT-PCR. Bioinformatics programs, luciferase assay, public dataset analysis and functional experiments were used to uncover the role of miR-622 and its target in breast cancer cells. RESULTS: miR-622 is downregulated in plasma and in tissues of breast cancer patients respect to healthy controls and its downregulation is significantly associated with advanced grade and high Ki67 level. Modulation of miR-622 affects the motility phenotype of breast cancer cells. NUAK1 kinase is a functional target of miR-622, it is associated with poor clinical outcomes of breast cancer patients and is inversely correlated with miR-622 level. CONCLUSIONS: miR-622/NUAK1 axis is deregulated in breast cancer patients and affects the motility phenotype of breast cancer cells. Importantly, miR-622 and NUAK1 hold promises as biomarkers and as targets for breast cancers.

COVID-19: viral-host interactome analyzed by network based-approach model to study pathogenesis of SARS-CoV-2 infection.

BACKGROUND: Epidemiological, virological and pathogenetic characteristics of SARS-CoV-2 infection are under evaluation. A better understanding of the pathophysiology associated with COVID-19 is crucial to improve treatment modalities and to develop effective prevention strategies. Transcriptomic and proteomic data on the host response against SARS-CoV-2 still have anecdotic character; currently available data from other coronavirus infections are therefore a key source of information. METHODS: We investigated selected molecular aspects of three human coronavirus (HCoV) infections, namely SARS-CoV, MERS-CoV and HCoV-229E, through a network based-approach. A functional analysis of HCoV-host interactome was carried out in order to provide a theoretic host-pathogen interaction model for HCoV infections and in order to translate the results in prediction for SARS-CoV-2 pathogenesis. The 3D model of S-glycoprotein of SARS-CoV-2 was compared to the structure of the corresponding SARS-CoV, HCoV-229E and MERS-CoV S-glycoprotein. SARS-CoV, MERS-CoV, HCoV-229E and the host interactome were inferred through published protein-protein interactions (PPI) as well as gene co-expression, triggered by HCoV S-glycoprotein in host cells. RESULTS: Although the amino acid sequences of the S-glycoprotein were found to be different between the various HCoV, the structures showed high similarity, but the best 3D structural overlap shared by SARS-CoV and SARS-CoV-2, consistent with the shared ACE2 predicted receptor. The host interactome, linked to the S-glycoprotein of SARS-CoV and MERS-CoV, mainly highlighted innate immunity pathway components, such as Toll Like receptors, cytokines and chemokines. CONCLUSIONS: In this paper, we developed a network-based model with the aim to define molecular aspects of pathogenic phenotypes in HCoV infections. The resulting pattern may facilitate the process of structure-guided pharmaceutical and diagnostic research with the prospect to identify potential new biological targets.

The New Paradigm of Network Medicine to Analyze Breast Cancer Phenotypes.

Breast cancer (BC) is a heterogeneous and complex disease as witnessed by the existence of different subtypes and clinical characteristics that poses significant challenges in disease management. The complexity of this tumor may rely on the highly interconnected nature of the various biological processes as stated by the new paradigm of Network Medicine. We explored The Cancer Genome Atlas (TCGA)-BRCA data set, by applying the network-based algorithm named SWItch Miner, and mapping the findings on the human interactome to capture the molecular interconnections associated with the disease modules. To characterize BC phenotypes, we constructed protein-protein interaction modules based on "hub genes", called switch genes, both common and specific to the four tumor subtypes. Transcriptomic profiles of patients were stratified according to both clinical (immunohistochemistry) and genetic (PAM50) classifications. 266 and 372 switch genes were identified from immunohistochemistry and PAM50 classifications, respectively. Moreover, the identified switch genes were functionally characterized to select an interconnected pathway of disease genes. By intersecting the common switch genes of the two classifications, we selected a unique signature of 28 disease genes that were BC subtype-independent and classification subtype-independent. Data were validated both in vitro (10 BC cell lines) and ex vivo (66 BC tissues) experiments. Results showed that four of these hub proteins (AURKA, CDC45, ESPL1, and RAD54L) were over-expressed in all tumor subtypes. Moreover, the inhibition of one of the identified switch genes (AURKA) similarly affected all BC subtypes. In conclusion, using a network-based approach, we identified a common BC disease module which might reflect its pathological signature, suggesting a new vision to face with the disease heterogeneity.

Biobanking in health care: evolution and future directions.

BACKGROUND: The aim of the present review is to discuss how the promising field of biobanking can support health care research strategies. As the concept has evolved over time, biobanks have grown from simple biological sample repositories to complex and dynamic units belonging to large infrastructure networks, such as the Pan-European Biobanking and Biomolecular Resources Research Infrastructure (BBMRI). Biobanks were established to support scientific knowledge. Different professional figures with varied expertise collaborate to obtain and collect biological and clinical data from human subjects. At same time biobanks preserve the human and legal rights of each person that offers biomaterial for research. METHODS: A literature review was conducted in April 2019 from the online database PubMed, accessed through the Bibliosan platform. Four primary topics related to biobanking will be discussed: (i) evolution, (ii) bioethical issues, (iii) organization, and (iv) imaging. RESULTS: Most biobanks were founded as local units to support specific research projects, so they evolved in a decentralized manner. The consequence is an urgent needing for procedure harmonization regarding sample collection, processing, and storage. Considering the involvement of biomaterials obtained from human beings, different ethical issues such as the informed consent model, sample ownership, veto rights, and biobank sustainability are debated. In the face of these methodological and ethical challenges, international organizations such as BBMRI play a key role in supporting biobanking activities. Finally, a unique development is the creation of imaging biobanks that support the translation of imaging biomarkers (identified using a radiomic approach) into clinical practice by ensuring standardization of data acquisition and analysis, accredited technical validation, and transparent sharing of biological and clinical data. CONCLUSION: Modern biobanks permit large-scale analysis for individuation of specific diseases biomarkers starting from biological or digital material (i.e., bioimages) with well-annotated clinical and biological data. These features are essential for improving personalized medical approaches, where effective biomarker identification is a critical step for disease diagnosis and prognosis.

Expanding Usutu virus circulation in Italy: detection in the Lazio region, central Italy, 2017 to 2018.

Blood donation screening for West Nile virus (WNV) was mandatory in the Lazio region in 2017 and 2018 (June-November) according to the national surveillance plan. In these years, all five donations reactive in WNV nucleic acid amplification tests harboured instead Usutu virus (USUV). Clade 'Europe 2' was identified in four blood donations and a 2018 mosquito pool. The cocirculation of WNV and USUV in Lazio warrants increased laboratory support and awareness of possible virus misidentification.

A genetic portrait of the South-Eastern Carpathians based on autosomal short tandem repeats loci used in forensics.

OBJECTIVES: This work aimed to describe the genetic landscape of the Balkan Peninsula, as revealed by STR markers commonly used in forensics and spatial methods specifically developed for genetic data. METHODS: We generated and analyzed 16 short tandem repeats (STRs) autosomal genotypes in 287 subjects from ten administrative/geographical regions of Eastern Europe (Romania and the Republic of Moldova). We report estimates of the allele frequencies in these sub-populations, their fixation indexes, and use these results to complement previous spatial analyses of Southern Europe. RESULTS: In seven out of ten analyzed regional samples the heterozygosity, averaged across loci, was lower than expected. The average Fis was 0.011. Among the 16 loci, five returned a significant fixation index Fst. The composite Fst across the 16 loci, among the 10 regional samples, was 0.00417, a figure twice as large as that obtained with the same markers across the entire Northern Mediterranean. The first spatial principal component (sPC1) returned the picture of a Central-European pattern of frequencies for the Carpathians, which extended to the Southern boundary of the Balkan Peninsula. However, the 8 alleles extracted by sPC1 returned a picture of a strong reduction of the migration rate in the Carpathian region, mostly between the inner locations. CONCLUSIONS: Our results revealed an unexpected heterogeneity in the area. We believe that populations from some regions will require treatment as distinct entities when considered in forensic applications.

Enlarging the gene-geography of Europe and the Mediterranean area to STR loci of common forensic use: longitudinal and latitudinal frequency gradients.

BACKGROUND: Tetranucleotide Short Tandem Repeats (STRs) for human identification and common use in forensic cases have recently been used to address the population genetics of the North-Eastern Mediterranean area. However, to gain confidence in the inferences made using STRs, this kind of analysis should be challenged with changes in three main aspects of the data, i.e. the sizes of the samples, their distance across space and the genetic background from which they are drawn. AIM: To test the resilience of the gradients previously detected in the North-Eastern Mediterranean to the enlargement of the surveyed area and population set, using revised data. SUBJECTS AND METHODS: STR genotype profiles were obtained from a publicly available database (PopAffilietor databank) and a dataset was assembled including >7000 subjects from the Arabian Peninsula to Scandinavia, genotyped at eight loci. Spatial principal component analysis (sPCA) was applied and the frequency maps of the nine alleles which contributed most strongly to sPC1 were examined in detail. RESULTS: By far the greatest part of diversity was summarised by a single spatial principal component (sPC1), oriented along a SouthEast-to-NorthWest axis. The alleles with the top 5% squared loadings were TH01(9.3), D19S433(14), TH01(6), D19S433(15.2), FGA(20), FGA(24), D3S1358(14), FGA(21) and D2S1338(19). These results confirm a clinal pattern over the whole range for at least four loci (TH01, D19S433, FGA, D3S1358). CONCLUSIONS: Four of the eight STR loci (or even alleles) considered here can reproducibly capture continental arrangements of diversity. This would, in principle, allow for the exploitation of forensic data to clarify important aspects in the formation of local gene pools.