In collaboration with Prof. Ulrike Nowak-Göttl (UK-SH), we are investigating classical and genetic risk factors for stroke and thromboembolism in childhood. In addition, we determined potential combined effects of individual SNPs that cannot be detected by conventional association. To this end, we examined the entire GWAS dataset from a systems biology perspective, incorporating information on protein interactions into our analyses. This analysis clearly demonstrates the complex interplay of genes at the interface between the vascular wall and coagulation in the pathogenesis of pediatric stroke and underscores the need to systematically investigate complex diseases with regard to dysregulated regulatory circuits. This is necessary to better understand the complex interplay of genes and proteins at various levels and their impact on the predisposition to complex diseases. The results were published in the internationally renowned journal Blood (Arning et al. Blood 2012). In addition, Monika Stoll was invited to the internationally renowned FASEB Scientific Research Conference in 2013 to present on this work. Using specially developed software (PostGWAS), we gained insights into the biological networks that may underlie the predisposition to stroke in childhood. The accompanying manuscript for the PostGWAS software was successfully published in 2013 (Hiersche et al., PLoS ONE) and simultaneously formed the basis for Mr. Hiersche's successful doctorate in the summer of 2013. In 2011, we initiated a study to resequence 46 affected children and their healthy siblings, which was sequenced on our Illumina NGS platform with 75x coverage. Our preliminary analyses, using our dedicated IT infrastructure, identified approximately 3,000 SNVs in 48 affected children and 48 unaffected siblings, 30 of which are potentially causative (coding) variants. These were submitted for further detailed studies in 2012-2014. In 2012 and 2013, additional validation experiments using Sanger sequencing helped to experimentally exclude false-positive mutations and further reduce the number of candidate genes and SNPs to be subsequently investigated. Subsequently, the remaining candidate SNPs were genotyped using TaqMan technology in the entire cohort (approximately 300 families) to estimate the population risk of these variants. These experiments began in 2012 and continued in 2013, and will be completed in 2014.