Common variants in the haemostatic gene pathway contribute to risk of early-onset myocardial infarction in the Italian population
THROMBOSIS AND HAEMOSTASIS
Authors: Guella, Ilaria; Duga, Stefano; Ardissino, Diego; Merlini, Pier Angelica; Peyvandi, Flora; Mannucci, Pier Mannuccio; Asselta, Rosanna
Abstract
Occlusive coronary thrombus formation superimposed on an atherosclerotic plaque is the ultimate event leading to myocardial infarction (MI). Therefore, haemostatic proteins may represent important players in the pathogenesis of MI. It was the objective of this study to evaluate, in a comprehensive way, the role of haemostatic gene polymorphisms in predisposition to premature MI. A total of 810 single nucleotide polymorphisms (SNPs) in 37 genes were assessed for association with MI in a large cohort (1,670 males, 210 females) of Italian patients who suffered from an MI event before the age of 45, and an equal number of controls. Thirly-eight SNPs selected from the literature were genotyped using the SNPlex technology, whereas genotypes for the remaining 772 SNPs were extracted from a previous genome-wide association study. Genotypes were analysed by a standard case-control analysis corrected for classical cardiovascular risk factors, and by haplotype analysis. A weighted Genetic Risk Score (GRS) was calculated. Evidence for association with MI after covariate correction was found for 35 SNPs in 12 loci: F5, PROS1, F11, ITGA2, F12, F13A1, SERPINE1, PLAT, VWF, THBD, PROCR, and F9. The weighted GRS was constructed by including the top SNP for each of the 12 associated loci. The GRS distribution was significantly different between cases and controls, and subjects in the highest quintile had a 2.69-fold increased risk for MI compared with those in the lowest quintile. Our results suggest that a GRS, based on the combined effect of several risk alleles in different haemostatic genes, is associated with an increased risk of MI.
Homozygous intronic mutation leading to inefficient transcription combined with a novel frameshift mutation in F13A1 gene causes FXIII deficiency
JOURNAL OF HUMAN GENETICS
Authors: Wang, Wei; Huang, Lijun; Ma, Qiuling; Xiao, Deqian; Chen, Xiaodan; Yang, Zhigang; Wang, Xiaoying; Zhou, Keyuan; Li, Gang; Xiao, Man; Du, Guankui; Hao, Xinbao; Cai, Wangwei
Abstract
Two novel mutations, 602-605delAAAG in exon 5 and Int1(+12)C > A, of the F13A1 gene were identified in a Chinese factor XIII (FXIII)-deficient family. The 602-605delAAAG mutation results in the premature termination of translation. To determine the functional effect of the Int1(+12)A mutation, we transiently expressed luciferase reporters in U937 cells. We found that the first 951 bp of F13A1 intron 1 is involved in regulating the expression of the F13A1 gene and that Int1(+12)A results in its reduced expression. Electrophoretic mobility shift assay indicated that Int1(+12)A causes reduced protein binding. An Sp1 site was predicted in the sequence containing Int1(+12)C, which the Int1(+12)A mutation eliminates. Co-transfection of a plasmid expressing Sp1 revealed that Sp1 is involved in regulating the expression of FXIIIA and that Int1(+12) A leads to inefficient transcription. These results provide the first insight into a novel regulatory mechanism involving intron 1 in the F13A1 gene. Journal of Human Genetics (2011) 56, 460-463; doi:10.1038/jhg.2011.41; published online 21 April 2011