Development and evaluations of the ancestry informative markers of the VISAGE Enhanced Tool for Appearance and Ancestry.

The VISAGE Enhanced Tool for Appearance and Ancestry (ET) has been designed to combine markers for the prediction of bio-geographical ancestry plus a range of externally visible characteristics into a single massively parallel sequencing (MPS) assay. We describe the development of the ancestry panel markers used in ET, and the enhanced analyses they provide compared to previous MPS-based forensic ancestry assays. As well as established autosomal single nucleotide polymorphisms (SNPs) that differentiate sub-Saharan African, European, East Asian, South Asian, Native American, and Oceanian populations, ET includes autosomal SNPs able to efficiently differentiate populations from Middle East regions. The ability of the ET autosomal ancestry SNPs to distinguish Middle East populations from other continentally defined population groups is such that characteristic patterns for this region can be discerned in genetic cluster analysis using STRUCTURE. Joint cluster membership estimates showing individual co-ancestry that signals North African or East African origins were detected, or cluster patterns were seen that indicate origins from central and Eastern regions of the Middle East. In addition to an augmented panel of autosomal SNPs, ET includes panels of 85 Y-SNPs, 16 X-SNPs and 21 autosomal Microhaplotypes. The Y- and X-SNPs provide a distinct method for obtaining extra detail about co-ancestry patterns identified in males with admixed backgrounds. This study used the 1000 Genomes admixed African and admixed American sample sets to fully explore these enhancements to the analysis of individual co-ancestry. Samples from urban and rural Brazil with contrasting distributions of African, European, and Native American co-ancestry were also studied to gauge the efficiency of combining Y- and X-SNP data for this purpose. The small panel of Microhaplotypes incorporated in ET were selected because they showed the highest levels of haplotype diversity amongst the seven population groups we sought to differentiate. Microhaplotype data was not formally combined with single-site SNP genotypes to analyse ancestry. However, the haplotype sequence reads obtained with ET from these loci creates an effective system for de-convoluting two-contributor mixed DNA. We made simple mixture experiments to demonstrate that when the contributors have different ancestries and the mixture ratios are imbalanced (i.e., not 1:1 mixtures) the ET Microhaplotype panel is an informative system to infer ancestry when this differs between the contributors.

Acute respiratory admissions in Thessaloniki, Greece: 14-year follow-up.

BACKGROUND: Acute exacerbations of respiratory diseases are a common cause of hospitalization among infants and children. AIM: To assess the epidemiological characteristics of asthma, bronchiolitis and croup among hospitalized children in Thessaloniki, from 1990 to 2003 included. METHODS: Data from the patient registry with discharge diagnosis "asthma", "bronchiolitis" and "croup" were analyzed retrospectively, in five Paediatric Departments of Thessaloniki. Age and sex of the patients, as well as the month of admission were taken into consideration. RESULTS: A total of 8762 admissions of children (aged 3 months-14 years) with the diagnosis of asthma, "bronchiolitis" and "croup", were identified. Sex distribution was 65.86% males (64.86% bronchiolitis, 65.26% asthma and 70.31% croup). Asthma admissions decreased by 53.65%, croup admissions decreased by 4.73%, while bronchiolitis admissions increased by 25.03%, during the study period. A clear seasonal variation was found in all the three diseases, with the lowest incidence during summer months. Moreover there were two peaks for asthma (one during spring and a second during autumn), one peak for bronchiolitis (during winter early spring) and one peak for croup (during autumn). CONCLUSIONS: Paediatric asthma and croup admissions have declined during the last 14 years, in contrast with bronchiolitis admissions, which showed an increased tendency. More frequent use of inhaled steroids and induction of asthma education programs may have contributed to decreasing asthma admission rates.