The C242T polymorphism of the NAD(P)H oxidase p22(phox) subunit is associated with an enhanced risk for cerebrovascular disease at a young age

Background and Purpose: Oxidative stress has been proposed as a major contributing factor for vascular disease, that acts independently from its participation in predisposing disorders such as diabetes and arterial hypertension. A functionally relevant C242T polymorphism of the CYBA gene encoding the NAD(P)H oxidase p22(phox) subunit, is supposed to lead to an abnormal reduction in the generation of reactive oxygen species in vascular smooth-muscle and endothelial cells. Methods: We investigated the p22(phox) C242T single-nucleotide polymorphism by polymerase chain reaction in consecutive patients with ischemic stroke or transient ischemic attack under the age of 50 (n = 161) and in population-based control subjects (n = 136). Results: Homozygosity for the T variant was associated with an enhanced risk for cerebral ischemia (odds ratio 3.85, confidence interval 1.39-10.64) after adjusting for classical risk factors. Risk for cerebral ischemia was not increased in heterozygous subjects. Conclusion: The p22(phox) C242T single-nucleotide polymorphism is associated with stroke risk. This finding supports the hypothesis that oxidative stress may contribute to stroke pathogenesis. Copyright (C) 2008 S. Karger AG, Basel

Acute Cerebrovascular Disease in the Young The Stroke in Young Fabry Patients Study

Background and Purpose-Strokes have especially devastating implications if they occur early in life; however, only limited information exists on the characteristics of acute cerebrovascular disease in young adults. Although risk factors and manifestation of atherosclerosis are commonly associated with stroke in the elderly, recent data suggests different causes for stroke in the young. We initiated the prospective, multinational European study Stroke in Young Fabry Patients (sifap) to characterize a cohort of young stroke patients. Methods-Overall, 5023 patients aged 18 to 55 years with the diagnosis of ischemic stroke (3396), hemorrhagic stroke (271), transient ischemic attack (1071) were enrolled in 15 European countries and 47 centers between April 2007 and January 2010 undergoing a detailed, standardized, clinical, laboratory, and radiological protocol. Results-Median age in the overall cohort was 46 years. Definite Fabry disease was diagnosed in 0.5% (95% confidence interval, 0.4%-0.8%; n=27) of all patients; and probable Fabry disease in additional 18 patients. Males dominated the study population (2962/59%) whereas females outnumbered men (65.3%) among the youngest patients (18-24 years). About 80.5% of the patients had a first stroke. Silent infarcts on magnetic resonance imaging were seen in 20% of patients with a first-ever stroke, and in 11.4% of patients with transient ischemic attack and no history of a previous cerebrovascular event. The most common causes of ischemic stroke were large artery atherosclerosis (18.6%) and dissection (9.9%). Conclusions-Definite Fabry disease occurs in 0.5% and probable Fabry disease in further 0.4% of young stroke patients. Silent infarcts, white matter intensities, and classical risk factors were highly prevalent, emphasizing the need for new early preventive strategies

Common variation in PHACTR1 is associated with susceptibility to cervical artery dissection

Cervical artery dissection (CeAD), a mural hematoma in a carotid or vertebral artery, is a major cause of ischemic stroke in young adults although relatively uncommon in the general population (incidence of 2.6/100,000 per year). Minor cervical traumas, infection, migraine and hypertension are putative risk factors, and inverse associations with obesity and hypercholesterolemia are described. No confirmed genetic susceptibility factors have been identified using candidate gene approaches. We performed genome-wide association studies (GWAS) in 1,393 CeAD cases and 14,416 controls. The rs9349379[G] allele (PHACTR1) was associated with lower CeAD risk (odds ratio (OR) = 0.75, 95% confidence interval (CI) = 0.69-0.82; P = 4.46 × 10(-10)), with confirmation in independent follow-up samples (659 CeAD cases and 2,648 controls; P = 3.91 × 10(-3); combined P = 1.00 × 10(-11)). The rs9349379[G] allele was previously shown to be associated with lower risk of migraine and increased risk of myocardial infarction. Deciphering the mechanisms underlying this pleiotropy might provide important information on the biological underpinnings of these disabling conditions

A probabilistic pathway score (PROPS) for classification with applications to inflammatory bowel disease

Abstract Summary Gene-based supervised machine learning classification models have been widely used to differentiate disease states, predict disease progression and determine effective treatment options. However, many of these classifiers are sensitive to noise and frequently do not replicate in external validation sets. For complex, heterogeneous diseases, these classifiers are further limited by being unable to capture varying combinations of genes that lead to the same phenotype. Pathway-based classification can overcome these challenges by using robust, aggregate features to represent biological mechanisms. In this work, we developed a novel pathway-based approach, PRObabilistic Pathway Score, which uses genes to calculate individualized pathway scores for classification. Unlike previous individualized pathway-based classification methods that use gene sets, we incorporate gene interactions using probabilistic graphical models to more accurately represent the underlying biology and achieve better performance. We apply our method to differentiate two similar complex diseases, ulcerative colitis (UC) and Crohn’s disease (CD), which are the two main types of inflammatory bowel disease (IBD). Using five IBD datasets, we compare our method against four gene-based and four alternative pathway-based classifiers in distinguishing CD from UC. We demonstrate superior classification performance and provide biological insight into the top pathways separating CD from UC. Availability and Implementation PROPS is available as a R package, which can be downloaded at http://simtk.org/home/props or on Bioconductor. Contact [email protected] Supplementary information Supplementary data are available at Bioinformatics online