Risk Burden of Lipoprotein Metabolic Gene Haplotypes

This study has been completed.
Sponsor:
Collaborator:
Information provided by:
Intermountain Health Care, Inc.
ClinicalTrials.gov Identifier:
NCT00090441
First received: August 26, 2004
Last updated: January 3, 2013
Last verified: December 2012
  Purpose

To investigate the role in coronary heart disease (CHD) of intragenic variation in a network of six genes affecting lipoprotein transport and metabolism.


Condition
Atherosclerosis
Cardiovascular Diseases
Coronary Disease
Heart Diseases

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Retrospective

Resource links provided by NLM:


Further study details as provided by Intermountain Health Care, Inc.:

Primary Outcome Measures:
  • To discover all common single nucleotide polymorphisms among a set of 6 key genes in the reverse cholesterol transport system and test them for associations with angiographic coronary artery disease. [ Designated as safety issue: No ]

Enrollment: 4303
Study Start Date: August 2004
Study Completion Date: July 2008
Primary Completion Date: July 2008 (Final data collection date for primary outcome measure)
Detailed Description:

BACKGROUND:

In recent years, a number of candidate genetic variants (e.g., single nucleotide polymorphisms, SNPs) have been reported to be associated with coronary heart disease (CHD). However, these association studies have suffered from variability and failures of replication. This may result in part from selection of marker SNPs in linkage disequilibrium (LD) with true disease-related SNPs or with other effect-modulating genetic variants. Other issues include the play of chance in samples of limited size, population stratification artifacts, and small effect size for single SNPs. A recent discovery is that the genome is organized into largely invariant DNA fragments at the population level characterized by infrequent recombination events interspersed with "hotspots" of recombination and designated "haplotype blocks". These haplotype blocks can be determined by creating a dense map of SNPs across the gene of interest and analyzing population level LD. A few SNPs then can be chosen that designate ("tag") each haplotype block and used to comprehensively assess disease associations across the entire gene. Applying this approach to multiple genes in pathways critical to vascular health and assessing combinations of genes is likely to increase the power to discover genetic associations with CHD risk.

DESIGN NARRATIVE:

The study will establish high density SNP maps across exons, splice regions, and 5' and 3' regulatory regions of 6 genes that play key roles in lipoprotein transport and metabolism (ABCA1, CETP, LCAT, HL, LPL, SRB1); introns will be examined for 2 of the genes (CETP, LPL). By analyzing combinations of haplotype-tagging (ht) SNPs, "genetic burden" can be scored and correlated with CHD risk at 4 levels: 1) biomarker (lipid/lipoprotein levels), 2) anatomic (angiographic) CHD, 3) clinical outcome (death/MI), and 4) (exploratory) response to lipid-lowering. Testing will be performed in 3 large, distinct, but complementary Utah populations at primary or secondary risk of premature CHD. Testing will occur in 2 stages to establish reproducibility: an initial screening phase followed by a confirmation phase (for genetic markers and combinations showing promise) in a larger, independent sample. The study will employ novel methods that combine high-throughput SNP discovery and genotyping capability with genetic epidemiological methods to identify the haplotype blocks within and surrounding the genes of interest, identify htSNPs, and assess disease associations with individual and combinations of htSNPs ("genetic burden"). To this, the study brings large, well characterized databases, assembled and followed for up to 9 years, which will be further expanded under the current project.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population

Study subjects for the primary association study were selected from Intermountain Healthcare's ongoing Angiographic Registry and DNA Bank.

Criteria

Men aged ≤60 years and women ≤70 years. Approximately 3,000 subjects (∼2,000 CAD cases and ∼1,000 angiographically normal controls, matched 2:1 for sex, age, and date of registry entry) were selected. A separate set of cases with highly familial premature CAD (first-degree relative with CHD onset <55 in men, <65 in women) from the University of Utah Cardiovascular Genetics Family Tree Registry and a separate set of controls (randomly invited from a public records database) were enrolled as a replication set.

  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00090441

Sponsors and Collaborators
Intermountain Health Care, Inc.
Investigators
Principal Investigator: Jeffrey Anderson, MD Intermountain Health Care; University of Utah School of Medicine
  More Information

No publications provided

ClinicalTrials.gov Identifier: NCT00090441     History of Changes
Other Study ID Numbers: 1265, 5R01HL071878-04
Study First Received: August 26, 2004
Last Updated: January 3, 2013
Health Authority: United States: Federal Government

Additional relevant MeSH terms:
Atherosclerosis
Arteriosclerosis
Cardiovascular Diseases
Coronary Disease
Coronary Artery Disease
Heart Diseases
Arterial Occlusive Diseases
Vascular Diseases
Myocardial Ischemia

ClinicalTrials.gov processed this record on August 28, 2014