Human leukocyte antigen in sickness and in health : Ankylosing spondylitis and HLA in Sweden

The human leukocyte antigen (HLA) plays a major role in keeping us healthy, but some of the HLA alleles can contribute to disease susceptibility. One example is HLA-B*27, which confers increased susceptibility of ankylosing spondylitis and represents one of the strongest genetic associations found in any common human disease. Ankylosing spondylitis shows a strong sex ratio skew (2-3:1 male to female) and studies confirm the existence of sexual-dimorphism in the presentation of this disease. The genetic predisposition for this, however, has not previously been studied.  A Swedish ankylosing spondylitis population was sequenced with a targeted array to investigate the existence of sex-specific associations. RUNX3 was revealed to be associated in males by a univariate test, while aggregate tests revealed the HLA gene MICB to be associated in females. Functional validation demonstrated that the risk variants in RUNX3 increase expression, and MICB changed the transcription factor binding sites. Interestingly, since the disease involves bone changes, both RUNX3 and one of the MICB variants had effect in the bone cell line, SaOS-2. In order to help researchers obtain more controls for HLA analysis, an HLA allele bioresource (SweHLA) was generated from 1,000 Swedish genomes. The alleles were typed with three to four HLA typing software programs and results were combined by an n-1methodology. This produced high quality alleles where the bias from each software program was diminished. The methodology from SweHLA was utilised to study HLA in ankylosing spondylitis. To investigate both sex-specific predisposition and HLA-B*27 independence, samples were subdivided into two populations (one population with mixed HLA-B*27 positive and negative samples and one with only HLA-B*27 positive samples) that in turn were grouped by sex. In the mixed population, several alleles were replicated from previous studies. This study also revealed three female-specific alleles, two of which were new and one that had previously been associated to the severity of radiological changes. The HLA-B*27 population revealed a previously unknown protective allele, HLA-A*24:02. Through deeper examination of the HLA-B*27 population, two amino acids in HLA-A, position 119 in the whole set and position 180 in the male set, were revealed to be protective. This thesis brings new insight into the genetic predisposition for a sex-skewed disease, demonstrating how sexual-dimorphism can be reflected in the genetic predisposition, hopefully leading to more similar studies. It also highlights the importance of methodology and demonstrate the drastic biases that can be imparted by software programs

Human leukocyte antigen in sickness and in health : Ankylosing spondylitis and HLA in Sweden

The human leukocyte antigen (HLA) plays a major role in keeping us healthy, but some of the HLA alleles can contribute to disease susceptibility. One example is HLA-B*27, which confers increased susceptibility of ankylosing spondylitis and represents one of the strongest genetic associations found in any common human disease. Ankylosing spondylitis shows a strong sex ratio skew (2-3:1 male to female) and studies confirm the existence of sexual-dimorphism in the presentation of this disease. The genetic predisposition for this, however, has not previously been studied.  A Swedish ankylosing spondylitis population was sequenced with a targeted array to investigate the existence of sex-specific associations. RUNX3 was revealed to be associated in males by a univariate test, while aggregate tests revealed the HLA gene MICB to be associated in females. Functional validation demonstrated that the risk variants in RUNX3 increase expression, and MICB changed the transcription factor binding sites. Interestingly, since the disease involves bone changes, both RUNX3 and one of the MICB variants had effect in the bone cell line, SaOS-2. In order to help researchers obtain more controls for HLA analysis, an HLA allele bioresource (SweHLA) was generated from 1,000 Swedish genomes. The alleles were typed with three to four HLA typing software programs and results were combined by an n-1methodology. This produced high quality alleles where the bias from each software program was diminished. The methodology from SweHLA was utilised to study HLA in ankylosing spondylitis. To investigate both sex-specific predisposition and HLA-B*27 independence, samples were subdivided into two populations (one population with mixed HLA-B*27 positive and negative samples and one with only HLA-B*27 positive samples) that in turn were grouped by sex. In the mixed population, several alleles were replicated from previous studies. This study also revealed three female-specific alleles, two of which were new and one that had previously been associated to the severity of radiological changes. The HLA-B*27 population revealed a previously unknown protective allele, HLA-A*24:02. Through deeper examination of the HLA-B*27 population, two amino acids in HLA-A, position 119 in the whole set and position 180 in the male set, were revealed to be protective. This thesis brings new insight into the genetic predisposition for a sex-skewed disease, demonstrating how sexual-dimorphism can be reflected in the genetic predisposition, hopefully leading to more similar studies. It also highlights the importance of methodology and demonstrate the drastic biases that can be imparted by software programs

Det sociala intranätet – ett forum för information, interaktion och identifikation

Titel: Det sociala intranätet – ett forum för information, interaktion och identifikation Författare: Jessika Hällerö, Emmy Nordin och Anna Salomonsson Uppdragsgivare: Semcon AB Kurs: Examensarbete i Medie- och kommunikationsvetenskap Institution: Institutionen för journalistik, massmedier och kommunikation (JMG) Göteborgs universitet Termin: Vårterminen 2012 Handledare: Malin Svenningsson Sidantal: 52 Antal ord: 15 020 Syfte: Syftet med studien är att undersöka hur Semcons konsulter reflekterar över sin organisationstillhörighet och hur de identifierar sig med sin arbetsgivare, samt att öka kunskapen om konsulternas inställning till och användandet av Semcons intranät. Metod: Kvalitativa samtalsintervjuer Material: Resultatet baseras på intervjuer med tio av Semcons konsulter. Huvudresultat: Genomgående för studien är att det tenderar att finnas en positiv och en negativ strömning i förhållande till frågorna. Vad gäller organisationsidentifikation finns det konsulter som identifierar sig med Semcon, konsulter som identifierar sig med arbetsplatsen samt de som är osäkra över sin organisationstillhörighet. Det råder även delade meningar kring hur ett socialt intranät kan medverka till att identifikationen med Semcon stärks. Vissa menar att ett socialt intranät kan bidra till identifieringen som Semconit, medan andra menar att det finns för lite information på avdelningsnivå för att uppnå detta. De positiva och negativa inställningarna återkommer i frågan om konsulternas inställning till intranätet som socialt forum. De positiva konsulterna menar att intranätet är deras återkoppling till Semcon. De negativa aspekterna konsulterna påpekar kan härledas ur deras avsaknad av ett yrkesrelaterat behov av interaktion via intranätet. Konsulterna är däremot eniga om att sökfunktionen och Employee Service Portal är de applikationer som är mest användbara i yrkesutövandet

Framtidens bioinformatikstöd för forskargrupper : En studie av SciLifeLabs användarstöd

Science for Life Laboratory:s (SciLifeLabs) användarstöd inom bioinformatik brister inom en del områden som användarutbildning, organisation och kommunikation. För att kunna tillgodose den snabba utvecklingen av biotekniken (till exempel nästa generations sekvensering) och inte minst SciLifeLab är det viktigt att dessa brister åtgärdas.  Efter att ha utfört en serie intervjuer med användare och leverantörer av SciLifeLabs sekvenseringstjänster har vi kommit fram till sex förslag för att täcka problemen inom de olika områdena. Förslagen sträcker sig från att vara enkla till mer omfattande att implementera.  Resultaten är riktade mot SciLifeLabs sekvenseringsplattform och är utformade för att kunna implementeras i dagsläget samt anpassas till framtida utvecklingar. Vi tror också att förslagen kan, med enkla modifieringar, användas av andra plattformar hos SciLifeLab

SweHLA : the high confidence HLA typing bio-resource drawn from 1000 Swedish genomes

There is a need to accurately call human leukocyte antigen (HLA) genes from existing short-read sequencing data, however there is no single solution that matches the gold standard of Sanger sequenced lab typing. Here we aimed to combine results from available software programs, minimizing the biases of applied algorithm and HLA reference. The result is a robust HLA population resource for the published 1000 Swedish genomes, and a framework for future HLA interrogation. HLA 2nd-field alleles were called using four imputation and inference methods for the classical eight genes (class I: HLA-A, HLA-B, HLA-C; class II: HLA-DPA1, HLA-DPB1, HLA-DQA1, HLA-DQB1, HLA-DRB1). A high confidence population set (SweHLA) was determined using an n−1 concordance rule for class I (four software) and class II (three software) alleles. Results were compared across populations and individual programs benchmarked to SweHLA. Per gene, 875 to 988 of the 1000 samples were genotyped in SweHLA; 920 samples had at least seven loci called. While a small fraction of reference alleles were common to all software (class I = 1.9% and class II = 4.1%), this did not affect the overall call rate. Gene-level concordance was high compared to European populations (&gt;0.83%), with COX and PGF the dominant SweHLA haplotypes. We noted that 15/18 discordant alleles (delta allele frequency &gt;2) were previously reported as disease-associated. These differences could in part explain across-study genetic replication failures, reinforcing the need to use multiple software solutions. SweHLA demonstrates a way to use existing NGS data to generate a population resource agnostic to individual HLA software biases.Title in thesis list of papers: SweHLA: the high confidence HLA typing bio-resource drawn from 1,000 Swedish genomes</p

Allele frequency spectrum of known ankylosing spondylitis associated variants in a Swedish population

Objective: The genetic predisposition to ankylosing spondylitis (AS) has been most widely studied in cohorts with European ancestry. However, within Europe, disease prevalence is higher in Sweden. Given this, we aimed to characterize known AS susceptibility variants in a homogeneous Swedish data set, assessing reproducibility and direction of effect. Method: The power to detect association within an existing Swedish targeted sequencing study (381 controls; 310 AS cases) was examined, and a set of published associations (n = 151) was intersected with available genotypes. Association to disease was calculated using logistic regression accounting for population structure, and HLA-B27 status was determined with direct polymerase chain reaction genotyping. Results: The cases were found to be 92.3% HLA-B27 positive, with the data set showing &gt;= 80% predictive power to replicate associations, with odds ratios &gt;= 1.6 over a range of allele frequencies (0.1-0.7). Thirty-four markers, representing 23 gene loci, were available for investigation. The replicated variants tagged MICA and IL23R loci (p &lt; 1.47 x 10(-3)), with variable direction of effect noted for gene loci IL1R1 and MST1. Conclusion: The Swedish data set successfully replicated both major histocompatibility complex (MHC) and non-MHC loci, and revealed a different replication pattern compared to discovery data sets. This was possibly due to population demographics, including HLA-B27 frequency and measured comorbidities

Using evolutionary constraint to define novel candidate driver genes in medulloblastoma

Current knowledge of cancer genomics remains biased against noncoding mutations. To systematically search for regulatory noncoding mutations, we assessed mutations in conserved positions in the genome under the assumption that these are more likely to be functional than mutations in positions with low conservation. To this end, we use whole-genome sequencing data from the International Cancer Genome Consortium and combined it with evolutionary constraint inferred from 240 mammals, to identify genes enriched in noncoding constraint mutations (NCCMs), mutations likely to be regulatory in nature. We compare medulloblastoma (MB), which is malignant, to pilocytic astrocytoma (PA), a primarily benign tumor, and find highly different NCCM frequencies between the two, in agreement with the fact that malignant cancers tend to have more mutations. In PA, a high NCCM frequency only affects the BRAF locus, which is the most commonly mutated gene in PA. In contrast, in MB, &gt;500 genes have high levels of NCCMs. Intriguingly, several loci with NCCMs in MB are associated with different ages of onset, such as the HOXB cluster in young MB patients. In adult patients, NCCMs occurred in, e.g., the WASF-2/ AHDC1/FGR locus. One of these NCCMs led to increased expression of the SRC kinase FGR and augmented responsiveness of MB cells to dasatinib, a SRC kinase inhibitor. Our analysis thus points to different molecular pathways in different patient groups. These newly identified putative candidate driver mutations may aid in patient stratification in MB and could be valuable for future selection of personalized treatment options

A novel canine reference genome resolves genomic architecture and uncovers transcript complexity

We present GSD_1.0, a high-quality domestic dog reference genome with chromosome length scaffolds and contiguity increased 55-fold over CanFam3.1. Annotation with generated and existing long and short read RNA-seq, miRNA-seq and ATAC-seq, revealed that 32.1% of lifted over CanFam3.1 gaps harboured previously hidden functional elements, including promoters, genes and miRNAs in GSD_1.0. A catalogue of canine "dark" regions was made to facilitate mapping rescue. Alignment in these regions is difficult, but we demonstrate that they harbour trait-associated variation. Key genomic regions were completed, including the Dog Leucocyte Antigen (DLA), T Cell Receptor (TCR) and 366 COSMIC cancer genes. 10x linked-read sequencing of 27 dogs (19 breeds) uncovered 22.1 million SNPs, indels and larger structural variants. Subsequent intersection with protein coding genes showed that 1.4% of these could directly influence gene products, and so provide a source of normal or aberrant phenotypic modifications. Here, the authors report an improved de novo reference genome for the domestic dog based on a female German Shepherd named Mischka. The new genome increases contiguity 55-fold over the previous dog assembly and uncovers functional elements that were not previously identifiable

Targeted sequencing reveals the somatic mutation landscape in a Swedish breast cancer cohort

Breast cancer (BC) is a genetically heterogeneous disease with high prevalence in Northern Europe. However, there has been no detailed investigation into the Scandinavian somatic landscape. Here, in a homogeneous Swedish cohort, we describe the somatic events underlying BC, leveraging a targeted next-generation sequencing approach. We designed a 20.5 Mb array targeting coding and regulatory regions of genes with a known role in BC (n = 765). The selected genes were either from human BC studies (n = 294) or from within canine mammary tumor associated regions (n = 471). A set of predominantly estrogen receptor positive tumors (ER +  85%) and their normal tissue counterparts (n = 61) were sequenced to ~ 140 × and 85 × mean target coverage, respectively. MuTect2 and VarScan2 were employed to detect single nucleotide variants (SNVs) and copy number aberrations (CNAs), while MutSigCV (SNVs) and GISTIC (CNAs) algorithms estimated the significance of recurrent somatic events. The significantly mutated genes (q ≤ 0.01) were PIK3CA (28% of patients), TP53 (21%) and CDH1 (11%). However, histone modifying genes contained the largest number of variants (KMT2C and ARID1A, together 28%). Mutations in KMT2C were mutually exclusive with PI3KCA mutations (p ≤ 0. 001) and half of these affect the formation of a functional PHD domain. The tumor suppressor CDK10 was deleted in 80% of the cohort while the oncogene MDM4 was amplified. Mutational signature analyses pointed towards APOBEC deaminase activity (COSMIC signature 2) and DNA mismatch repair (COSMIC signature 6). We noticed two significantly distinct patterns related to patient age; TP53 being more mutated in the younger group (29% vs 9% of patients) and CDH23 mutations were absent from the older group. The increased somatic mutation prevalence in the histone modifying genes KMT2C and ARID1A distinguishes the Swedish cohort from previous studies. KMT2C regulates enhancer activation and assists tumor proliferation in a hormone-rich environment, possibly pointing to a role in ER + BC, especially in older cases. Finally, age of onset appears to affect the mutational landscape suggesting that a larger age-diverse population incorporating more molecular subtypes should be studied to elucidate the underlying mechanisms