Whole-exome sequencing analyses in a Saudi Ischemic Stroke Cohort reveal association signals, and shows polygenic risk scores are related to Modified Rankin Scale Risk.

Ischemic stroke represents a significant societal burden across the globe. Rare high penetrant monogenic variants and less pathogenic common single nucleotide polymorphisms (SNPs) have been described as being associated with risk of diseases. Genetic studies in Saudi Arabian patients offer a greater opportunity to detect rare high penetrant mutations enriched in these consanguineous populations. We performed whole exome sequencing on 387 ischemic stroke subjects from Saudi Arabian hospital networks with up to 20,230 controls from the Saudi Human Genome Project and performed gene burden analyses of variants in 177 a priori loci derived from knowledge-driven curation of monogenic and genome-wide association studies of stroke. Using gene-burden analyses, we observed significant associations in numerous loci under autosomal dominant and/or recessive modelling. Stroke subjects with modified Rankin Scale (mRSs) above 3 were found to carry greater cumulative polygenic risk score (PRS) from rare variants in stroke genes (standardized PRS mean > 0) compared to the population average (standardized PRS mean = 0). However, patients with mRS of 3 or lower had lower cumulative genetic risk from rare variants in stroke genes (OR (95%CI) = 1.79 (1.29-2.49), p = 0.0005), with the means of standardized PRS at or lower than 0. In conclusion, gene burden testing in Saudi stroke populations reveals a number of statistically significant signals under different disease inheritance models. However, interestingly, stroke subjects with mRS of 3 or lower had lower cumulative genetic risk from rare variants in stroke genes and therefore, determining the potential mRS cutoffs to use for clinical significance may allow risk stratification of this population.

miRNA Expression Associated with HbF in Saudi Sickle Cell Anemia.

Background and Objectives: Sickle cell anemia (SCA) is a hereditary monogenic disease due to a single ß-globin gene mutation that codes for the production of sickle hemoglobin. Its phenotype is modulated by fetal hemoglobin (HbF), a product of γ-globin genes. Exploring the molecules that regulate γ-globin genes at both transcriptional and translational levels, including microRNA (miRNA), might help identify alternative therapeutic targets. Materials and Methods: Using next-generation sequencing we identified pre-miRNAs and mature miRNA expression signatures associated with different HbF levels in patients homozygous for the sickle hemoglobin gene. The involvement of identified miRNAs in potential SCD-related pathways was investigated with the DIANA TOOL and miRWalk 2.0 database. Results: miR-184 were most highly upregulated in reticulocytes. miR-3609 and miR-483-5p were most highly downregulated in sickle cell anemia with high HbF. miR-370-3p that regulates LIN28A, and miR-451a which is effective in modulating α- and ß- globin levels were also significantly upregulated. miRNA targeted gene pathway interaction identified BCL7A, BCL2L1, LIN28A, KLF6, GATA6, solute carrier family genes and ZNF genes associated with erythropoiesis, cell cycle regulation, glycosphingolipid biosynthesis, cAMP, cGMP-PKG, mTOR, MAPK and PI3K-AKT signaling pathways and cancer pathways. Conclusions: miRNA signatures and their target genes identified novel miRNAs that could regulate fetal hemoglobin production and might be exploited therapeutically.

Elevated plasma level of the glycolysis byproduct methylglyoxal on admission is an independent biomarker of mortality in ICU COVID-19 patients.

Biomarkers to identify ICU COVID-19 patients at high risk for mortality are urgently needed for therapeutic care and management. Here we found plasma levels of the glycolysis byproduct methylglyoxal (MG) were 4.4-fold higher in ICU patients upon admission that later died (n = 33), and 1.7-fold higher in ICU patients that survived (n = 32),compared to uninfected controls (n = 30). The increased MG in patients that died correlated inversely with the levels of the MG-degrading enzyme glyoxalase-1 (r2 = - 0.50), and its co-factor glutathione (r2 = - 0.63), and positively with monocytes (r2 = 0.29). The inflammation markers, SSAO (r2 = 0.52), TNF-α (r2 = 0.41), IL-1ß (r2 = 0.25), CRP (r2 = 0.26) also correlated positively with MG. Logistic regression analysis provides evidence of a significant relationship between the elevated MG upon admission into ICU and death (P < 0.0001), with 42% of the death variability explained. From these data we conclude that elevated plasma MG on admission is a novel independent biomarker that predicts mortality in ICU COVID-19 patients.

Prevalence of CYP2C19*2 carriers in Saudi ischemic stroke patients and the suitability of using genotyping to guide antiplatelet therapy in a university hospital setup.

OBJECTIVES: To mitigate the incidence of recurrent stroke in patients, dual antiplatelet therapy comprising aspirin and clopidogrel is usually administered. Clopidogrel is a prodrug and its bioactivation is catalyzed by cytochrome P450 (CYP)2C19. The main objective of this work was to determine the prevalence of CYP2C19*2 carriers in Saudi ischemic stroke patients and assess the suitability of using genotyping to guide antiplatelet therapy in a university hospital setup. METHODS: This prospective (2018-2019) study was conducted on 256 patients (age 61 ± 12.5) clinically diagnosed with ischemic stroke who were genotyped using Spartan RX CYP2C19 assay. RESULTS: From the total patient group (256), upon admission, 210 patients were prescribed either aspirin, clopidogrel or dual antiplatelet therapy. Of the 27 patients with the CYP2C19*2 allele who were prescribed clopidogrel (18) or dual antiplatelet therapy (9), only 21 patients could be followed up for a period of six months post stroke event, in addition to 21 age- and sex-matched patients with the normal allele. The CYP2C19*2 allele carriers had a statistically significant increased risk of recurrent stroke compared to patients carrying the normal allele. CONCLUSIONS: This study shows the suitability of using genotyping to guide antiplatelet therapy in ischemic stroke patients in a clinical setting.

Prevalence of CYP2C19*2 carriers in Saudi ischemic stroke patients and the suitability of using genotyping to guide antiplatelet therapy in a university hospital setup.

OBJECTIVES: To mitigate the incidence of recurrent stroke in patients, dual antiplatelet therapy comprising aspirin and clopidogrel is usually administered. Clopidogrel is a prodrug and its bioactivation is catalyzed by cytochrome P450 (CYP)2C19. The main objective of this work was to determine the prevalence of CYP2C19*2 carriers in Saudi ischemic stroke patients and assess the suitability of using genotyping to guide antiplatelet therapy in a university hospital setup. METHODS: This prospective (2018-2019) study was conducted on 256 patients (age 61 ± 12.5) clinically diagnosed with ischemic stroke who were genotyped using Spartan RX CYP2C19 assay. RESULTS: From the total patient group (256), upon admission, 210 patients were prescribed either aspirin, clopidogrel or dual antiplatelet therapy. Of the 27 patients with the CYP2C19*2 allele who were prescribed clopidogrel (18) or dual antiplatelet therapy (9), only 21 patients could be followed up for a period of six months post stroke event, in addition to 21 age- and sex-matched patients with the normal allele. The CYP2C19*2 allele carriers had a statistically significant increased risk of recurrent stroke compared to patients carrying the normal allele. CONCLUSIONS: This study shows the suitability of using genotyping to guide antiplatelet therapy in ischemic stroke patients in a clinical setting.