Usefulness of Single Nucleotide Polymorphisms as Predictors of Sudden Cardiac Death
AMERICAN JOURNAL OF CARDIOLOGY
Authors: Tamariz, Leonardo; Balda, Javier; Pareja, Dennise; Palacio, Ana; Myerburg, Robert J.; Conway, Douglas; Davis, Lea; Goldberger, Jeffrey J.
Abstract
The pathophysiology of sudden cardiac death (SCD) remains incompletely understood. Genetic mutations can create a favorable substrate for SCD. Our aim is to evaluate the evidence of single nucleotide polymorphisms (SNPs) as predictors of SCD. We searched the Medline database (2000 to 2017) and selected all case-control or cohort studies that reported associations between SNPs and SCD. Our search terms included "polymorphisms" and "sudden death." We collected the study design, population ethnic background, gene testing strategy, the association between the SNP and SCD, and the cardiovascular comorbidities of the population. Our search yielded 723 studies, of which we included 24 based upon our inclusion criteria. The studies had a total population of 78,165 participants, with a median age of 62.5 years (IQR 56 to 66) and 35% (IQR 13 to 32) were female. Almost all studies were conducted in white patients of European descent and the most commonly used genetic strategy was candidate gene panels. Fifteen of the studies had a case-control design that included SCD patients without known heart disease as the comparison group and the other 9 studies included patients with heart failure and coronary artery disease. The studies evaluated 53 SNPs and the most common genetic loci were SCNSA, RyR2, CASQ2, NOSA1P, and AGTR. SNPs with the 3 strongest statistically significant ORs >1 were: rs6684209 of CASQ2 (odds ratio [OR] 19), rs3814843 of CALM1 (OR 5.5), and rs35594137 of GJA5 (OR 3.6). In Conclusion, many SNPs are associated with SCD, with the strongest associations seen in SNPs of genes related to intracellular calcium handling. These findings were generated primarily using a candidate gene strategy in white patients with European descent. (C) 2019 Elsevier Inc. All rights reserved.
Characterization of a mutation in the lens-specific MP70 encoding gene of the mouse leading to a dominant cataract
EXPERIMENTAL EYE RESEARCH
Authors: Graw, J; Loster, J; Soewarto, D; Fuchs, H; Meyer, B; Reis, A; Wolf, E; Balling, R; De Angelis, MH
Abstract
During an ethylnitrosourea mutagenesis screen. Aey5. a new mouse mutation exhibiting an autosomal dominant congenital cataract was isolated. The cataractous phenotype is visible at the eye opening and progresses to a nuclear and zonular cataract at 2 months of age with no difference in onset or severity between heterozygous and homozygous mutants. Histological analysis revealed that fiber cell differentiation continues at the tens bow region, but the cell nuclei do not degrade normally and remain in the deeper cortex. Further, the lens nucleus has clefts of various sizes while the remainder of the eye was morphologically normal. The mutation was mapped to chromosome 3 between the markers D3Mit101 and D3Mit77 near the connexin encoding genes,Gja5 and Gja8. Sequence analysis revealed no differences in the Gja5 gene. but identified a T-->C mutation at position 191 in the Gja8 gone, which was confirmed by an additional Mva12691 restriction site in the genomic DNA of homozygous mutants. This mutation results in Val-->Ala substitution at codon 64 of connexin50 (Cx50) also known as lens membrane protein 70 (MP70). Aey5 represents the second dominant mouse cataract mutant affecting Cx50, a membrane protein preferentially expressed in the lens. Since: both mutations affect similar regions in the first extracellular domain this region appears to be critically important for its function in lens transparency. (C) 2001 Academic Press.