Non-atherosclerotic Dissection Research Articles

Diagnosing Monogenic Stroke at Younger Age.

An increasing number of monogenic conditions underlying stroke are being identified. We explored the possibilities of increasing the diagnostic yield of monogenic stroke in a population under 56 years of age. Fifty probands ≤55 years at their first stroke episode were characterized clinically and investigated by whole genome sequencing. Probands had one or more of: (1) one or more first to second degree relatives with stroke under 60 years or same stroke-causing condition/disease; (2) no hypertension, hypercholesterolemia, diabetes, heart disease, or smoking; or (3) either multiple stroke episodes or multiple arterial dissections. Variants with minor allele frequency under 0.01, identified by using our stroke gene panels, were assessed. The stroke subtypes, including large artery atherosclerotic, large artery nonatherosclerotic (tortuosity, dolichoectasia, aneurysm, nonatherosclerotic dissection, or occlusion), cerebral small vessel disease, cardioembolic (arrhythmia, heart defect, or cardiomyopathy), coagulation dysfunctions (venous thrombosis, arterial thrombosis, or bleeding tendency), intracerebral hemorrhage, vascular malformations (cavernoma or arteriovenous malformations), metabolic disorders, or cryptogenic embolic, were used for genotype-phenotype correlation. In a final step, we combined genetic and clinical information to determine if the genetic variant likely was the cause of stroke in the patients. Whole genome sequencing of younger patients with stroke identified 17 clinically matching genetic variants in 15 of 50 (30%) patients, while a stronger clinical correlation with stroke was established in only 6 (12%) of them. Stroke-related genetic variants were identified in 4 of 5 (80%) patients with cardioembolic stroke subtype, 3 of 4 (75%) with intracerebral hemorrhage, 7 of 18 (39%) with cryptogenic embolic stroke, 1 of 6 (17%) with small vessel disease, and 3 of 15 (20%) of patients with nonatherosclerotic large artery stroke, including 1 of 11 (9%) with cervical dissection stroke. Careful clinical interpretation of whole genome data using stroke gene panels can detect monogenic causes of early stroke, allowing individualized follow-up and opening new possibilities for potential treatment.

Updated Stroke Gene Panels: Rapid evolution of knowledge on monogenic causes of stroke

This article updates our previous Stroke Gene Panels (SGP) from 2017. Online Mendelian Inheritance in Man and PubMed were searched. We divided detected genes into two SGP groups, SGP1: genes reported in at least one person with stroke and associated with one or more clinical subgroups: large artery atherosclerotic, large artery non-atherosclerotic (tortuosity, dolichoectasia, aneurysm, non-atherosclerotic dissection or occlusion), cerebral small vessel diseases, cardio-embolic (arrhythmia, heart defect, cardiomyopathy), coagulation dysfunctions (venous thrombosis, arterial thrombosis, bleeding tendency), intracerebral hemorrhage, vascular malformations (cavernoma, arteriovenous malformations) and metabolism disorders; and SGP2: genes related to diseases that may predispose to stroke. We identified 168 SGP1 genes, 70 of these were validated for clinical practice. We also detected 72 SGP2 genes. Nine genes were removed because of conflicting evidence. The number of genes increased from 168 to 240 during 4.5-years, reflecting a dynamic evolution and the need for regular updates for research and clinical use.

A stroke gene panel for whole-exome sequencing.

Extensive analyses of known monogenic causes of stroke by whole-exome/genome sequencing are technically possible today. We here aimed to compile a comprehensive panel of genes associated with monogenic causes of stroke for use in clinical and research situations. We systematically searched the publically available database Online Mendelian Inheritance in Man, and validated the entries against original peer-reviewed publications in PubMed. First, we selected known pathogenic or putatively pathogenic stroke genes reported in at least one person with stroke, and classified the stroke phenotype for each gene into eight subgroups: (1) large artery atherosclerotic, (2) large artery non-atherosclerotic (tortuosity, dolichoectasia, aneurysm, non-atherosclerotic dissection, occlusion), (3) cerebral small-vessel diseases, (4) cardioembolic (arrhythmia, heart defect, cardiomyopathy), (5) coagulation dysfunctions (venous thrombosis, arterial thrombosis, bleeding tendency), (6) intracerebral hemorrhage, (7) vascular malformations (cavernoma, arteriovenous malformations), and (8) metabolism disorders. Second, we selected other genes that may plausibly cause stroke through diseases related to stroke, but without any documented stroke patient description. A third section comprised SNPs associated with stroke in genome-wide association studies (GWAS). We identified in total 214 genes: 120 associated with stroke, 62 associated with diseases that may cause stroke, and 32 stroke-related genes from recent GWAS. We describe these 214 genes and the clinical stroke subtype(s) associated with each of them. The resulting gene panel can be used to interpret exome sequencing results regarding monogenic stroke. Based on the panel's clinical phenotype description, the pathogenicity of novel variants in these genes may be evaluated in specific situations.