Comment Authors: Filipa Sotero and Diana Aguiar de Sousa, Department of Neurology, Hospital de Santa Maria, University of Lisbon, Portugal
Original Article: Maguire J, Bevan S, Stanne T et al. 2017 GISCOME – Genetics of Ischaemic Stroke Functional Outcome network: A protocol for an international multicentre genetic association study. European Stroke Journal. doi: 10.1177/2396987317704547
Stroke is one of the principal causes of adult disability. A genetic role in disease risk and susceptibility has been reported for stroke as well as for many other diseases, but how genetic factors influence stroke outcomes is less studied. Genome-wide associated studies (GWASs) may have an important role in this point, leading to the discovery of disease-associated loci across multiple phenotypes.
The present paper is a study protocol of the Genetics of Ischaemic Stroke Functional Outcome (GISCOME) network, which aims to detect and describe genetic factors influencing ischaemic stroke outcomes, using data from already performed GWASs.
The authors retrospectively collected data from twelve stroke projects, counting a total of eighteen cohorts. Phenotypic and genotypic data for each cohort was uploaded to central FTP secure servers. Modified Rankin Scale at 60–190 days was selected as the most readily available functional outcome variable. Baseline NIHSS was the selected measure for initial stroke severity, using the score taken as close to 24 h after stroke onset as possible (0-10 days).
Maguire and colleagues assembled a total of 8831 ischaemic stroke cases, all of them adults (>18 years) of European ancestry. Stroke severity at baseline was often mild. According with the variables summarized above, for this primary phase of the study, 5762 individuals from 16 cohorts were available with mRS, NIHSS and genotypic data.
This is the first international multicentre, large-scale GWAS on post-stroke outcomes. The GISCOME network has also managed to assemble the largest sample of detailed stroke outcome phenotypic and genotypic data. However, the retrospective design of this study is a limitation, with notable loss to follow up in some cohorts. Besides, as all cases belong to European ancestry, the study does not represent a global stroke population.
In the second phase, the authors expect to obtain more cases from new projects, seeking and inviting sites that are derived from more diverse ethno-geographic groups. A minimum set of variables are required for phase 2, which will include age, sex, stroke severity at 0–10 days and mRS at 60–190 days, as well as available GWAS or DNA. These planned analysis are considered as exploratory analyses, which will inform future prospective studies within this important field of stroke research.
The original article “GISCOME – Genetics of Ischaemic Stroke Functional Outcome network: A protocol for an international multicentre genetic association study.” is available in the Online First section of the European Stroke Journal.
1- Maguire J, Bevan S, Stanne T et al. 2017 GISCOME – Genetics of Ischaemic Stroke Functional Outcome network: A protocol for an international multicentre genetic association study. European Stroke Journal. doi: 10.1177/2396987317704547