Stroke Genetics Network (SiGN) study: design and rationale for a genome-wide association study of ischemic stroke subtypes.
Meschia JF., Arnett DK., Ay H., Brown RD., Benavente OR., Cole JW., de Bakker PIW., Dichgans M., Doheny KF., Fornage M., Grewal RP., Gwinn K., Jern C., Conde JJ., Johnson JA., Jood K., Laurie CC., Lee J-M., Lindgren A., Markus HS., McArdle PF., McClure LA., Mitchell BD., Schmidt R., Rexrode KM., Rich SS., Rosand J., Rothwell PM., Rundek T., Sacco RL., Sharma P., Shuldiner AR., Slowik A., Wassertheil-Smoller S., Sudlow C., Thijs VNS., Woo D., Worrall BB., Wu O., Kittner SJ., NINDS SiGN Study None.
BACKGROUND AND PURPOSE: Meta-analyses of extant genome-wide data illustrate the need to focus on subtypes of ischemic stroke for gene discovery. The National Institute of Neurological Disorders and Stroke SiGN (Stroke Genetics Network) contributes substantially to meta-analyses that focus on specific subtypes of stroke. METHODS: The National Institute of Neurological Disorders and Stroke SiGN includes ischemic stroke cases from 24 genetic research centers: 13 from the United States and 11 from Europe. Investigators harmonize ischemic stroke phenotyping using the Web-based causative classification of stroke system, with data entered by trained and certified adjudicators at participating genetic research centers. Through the Center for Inherited Diseases Research, the Network plans to genotype 10,296 carefully phenotyped stroke cases using genome-wide single nucleotide polymorphism arrays and adds to these another 4253 previously genotyped cases, for a total of 14,549 cases. To maximize power for subtype analyses, the study allocates genotyping resources almost exclusively to cases. Publicly available studies provide most of the control genotypes. Center for Inherited Diseases Research-generated genotypes and corresponding phenotypes will be shared with the scientific community through the US National Center for Biotechnology Information database of Genotypes and Phenotypes, and brain MRI studies will be centrally archived. CONCLUSIONS: The Stroke Genetics Network, with its emphasis on careful and standardized phenotyping of ischemic stroke and stroke subtypes, provides an unprecedented opportunity to uncover genetic determinants of ischemic stroke.