Research article

Genetic and functional association of FAM5C with myocardial infarction

Jessica J Connelly¹ , Svati H Shah^1,2 , Jennifer F Doss¹ , Shera Gadson¹ , Sarah Nelson¹ , David R Crosslin¹ , A Brent Hale¹ , Xuemei Lou¹ , Ty Wang¹ , Carol Haynes¹ , David Seo³ , David C Crossman⁴ , Vincent Mooser⁵ , Christopher B Granger² , Christopher JH Jones⁶ , William E Kraus^1,2 , Elizabeth R Hauser¹ and Simon G Gregory¹

¹Department of Medicine and Center for Human Genetics, Duke University Medical Center, Durham, NC, USA

²Department of Medicine and Division of Cardiology, Duke University Medical Center, Durham, NC, USA

³Miller School of Medicine, University of Miami, Miami, FL, USA

⁴University of Sheffield, Sheffield, UK

⁵GlaxoSmithKline, Philadelphia, PA, USA

⁶University of Wales College of Medicine, Cardiff, UK

author email corresponding author email

BMC Medical Genetics 2008, 9:33doi:10.1186/1471-2350-9-33

Published:	22 April 2008

Abstract

Background

We previously identified a 40 Mb region of linkage on chromosome 1q in our early onset coronary artery disease (CAD) genome-wide linkage scan (GENECARD) with modest evidence for linkage (n = 420, LOD 0.95). When the data are stratified by acute coronary syndrome (ACS), this modest maximum in the overall group became a well-defined LOD peak (maximum LOD of 2.17, D1S1589/D1S518). This peak overlaps a recently identified inflammatory biomarker (MCP-1) linkage region from the Framingham Heart Study (maximum LOD of 4.27, D1S1589) and a region of linkage to metabolic syndrome from the IRAS study (maximum LOD of 2.59, D1S1589/D1S518). The overlap of genetic screens in independent data sets provides evidence for the existence of a gene or genes for CAD in this region.

Methods

A peak-wide association screen (457 SNPs) was conducted of a region 1 LOD score down from the peak marker (168–198 Mb) in a linkage peak for acute coronary syndrome (ACS) on chromosome 1, within a family-based early onset coronary artery disease (CAD) sample (GENECARD).

Results

Polymorphisms were identified within the 'family with sequence similarity 5, member C' gene (FAM5C) that show genetic linkage to and are associated with myocardial infarction (MI) in GENECARD. The association was confirmed in an independent CAD case-control sample (CATHGEN) and strong association with MI was identified with single nucleotide polymorphisms (SNPs) in the 3' end of FAM5C. FAM5C genotypes were also correlated with expression of the gene in human aorta. Expression levels of FAM5C decreased with increasing passage of proliferating aortic smooth muscle cells (SMC) suggesting a role for this molecule in smooth muscle cell proliferation and senescence.

Conclusion

These data implicate FAM5C alleles in the risk of myocardial infarction and suggest further functional studies of FAM5C are required to identify the gene's contribution to atherosclerosis.