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Taghizadeh E, Mardani R, Rostami D, Taghizadeh H, Bazireh H, Hayat SMG. Molecular mechanisms, prevalence, and molecular methods for familial combined hyperlipidemia disease: A review. J Cell Biochem 2018; 120:8891-8898. [DOI: 10.1002/jcb.28311] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/28/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Eskandar Taghizadeh
- Department of Medical Genetics Faculty of Medicine, Mashhad University of Medical Sciences Mashhad Iran
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences Yasuj Iran
| | - Rajab Mardani
- Department of Biochemistry Pasteur Institute of Iran Tehran Iran
| | - Daryoush Rostami
- Department of School Allied Zabol University of Medical Sciences Zabol Iran
| | - Hassan Taghizadeh
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences Yasuj Iran
| | - Homa Bazireh
- Department of Industrial and Environmental Biotechnology National Institute of Genetic Engineering and Biotechnology Tehran Iran
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Abstract
PURPOSE OF REVIEW Combined hyperlipidemia (CHL) is a complex phenotype that is commonly encountered clinically and is often associated with the expression of early heart disease. The affixed adjective 'familial' gives the impression that the trait is monogenic, like familial hypercholesterolemia. But despite significant efforts, genetic studies have yielded little evidence of single gene determinants of CHL. RECENT FINDINGS Sophisticated linkage studies suggest that individual lipid components of the CHL phenotype - such as elevated LDL and triglyceride - each have several determinants that segregate independently in families. Furthermore, DNA sequencing shows that rare large-effect variants in genes such as LDL receptor (LDLR) and lipoprotein lipase are found in some CHL patients, explaining the elevated LDL cholesterol and triglyceride components, respectively. In addition, multiple common small-effect lipid-altering variants accumulate in an individual's genome, raising the LDL cholesterol and/or triglyceride components by multiple mechanisms. Finally, secondary factors, such as poor diet, obesity,fatty liver or diabetes further modulate the expression of the biochemically defined CHL phenotype. SUMMARY Given the current state of genetic understanding, CHL may be best conceptualized as a syndrome with common clinical presentation but multigenic causes, similar to other common conditions such as type 2 diabetes.
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Affiliation(s)
- Amanda J Brahm
- Department of Medicine, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
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Klop B, Verseyden C, Ribalta J, Salazar J, Masana L, Cabezas MC. MTP gene polymorphisms and postprandial lipemia in familial combined hyperlipidemia: Effects of treatment with atorvastatin. CLINICA E INVESTIGACION EN ARTERIOSCLEROSIS 2014; 26:49-57. [DOI: 10.1016/j.arteri.2013.11.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 11/14/2013] [Accepted: 11/18/2013] [Indexed: 10/25/2022]
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Brouwers MCGJ, van Greevenbroek MMJ, Stehouwer CDA, de Graaf J, Stalenhoef AFH. The genetics of familial combined hyperlipidaemia. Nat Rev Endocrinol 2012; 8:352-62. [PMID: 22330738 DOI: 10.1038/nrendo.2012.15] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Almost 40 years after the first description of familial combined hyperlipidaemia (FCHL) as a discrete entity, the genetic and metabolic basis of this prevalent disease has yet to be fully unveiled. In general, two strategies have been applied to elucidate its complex genetic background, the candidate-gene and the linkage approach, which have yielded an extensive list of genes associated with FCHL or its related traits, with a variable degree of scientific evidence. Some genes influence the FCHL phenotype in many pedigrees, whereas others are responsible for the affected state in only one kindred, thereby adding to the genetic and phenotypic heterogeneity of FCHL. This Review outlines the individual genes that have been described in FCHL and how these genes can be incorporated into the current concept of metabolic pathways resulting in FCHL: adipose tissue dysfunction, hepatic fat accumulation and overproduction, disturbed metabolism and delayed clearance of apolipoprotein-B-containing particles. Genes that affect metabolism and clearance of plasma lipoprotein particles have been most thoroughly studied. The adoption of new traits, in addition to the classic plasma lipid traits, could aid in the identification of new genes implicated in other pathways in FCHL. Moreover, systems genetic analysis, which integrates genetic polymorphisms with data on gene expression levels, lipidomics or metabolomics, will attribute functions to genetic variants in addition to revealing new genes.
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Affiliation(s)
- Martijn C G J Brouwers
- Department of Internal Medicine and Endocrinology, Maastricht University Medical Centre, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
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Fine mapping and association studies of a high-density lipoprotein cholesterol linkage region on chromosome 16 in French-Canadian subjects. Eur J Hum Genet 2009; 18:342-7. [PMID: 19844255 DOI: 10.1038/ejhg.2009.157] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Low levels of high-density lipoprotein cholesterol (HDL-C) are an independent risk factor for cardiovascular disease. To identify novel genetic variants that contribute to HDL-C, we performed genome-wide scans and quantitative association studies in two study samples: a Quebec-wide study consisting of 11 multigenerational families and a study of 61 families from the Saguenay-Lac St-Jean (SLSJ) region of Quebec. The heritability of HDL-C in these study samples was 0.73 and 0.49, respectively. Variance components linkage methods identified a LOD score of 2.61 at 98 cM near the marker D16S515 in Quebec-wide families and an LOD score of 2.96 at 86 cM near the marker D16S2624 in SLSJ families. In the Quebec-wide sample, four families showed segregation over a 25.5-cM (18 Mb) region, which was further reduced to 6.6 Mb with additional markers. The coding regions of all genes within this region were sequenced. A missense variant in CHST6 segregated in four families and, with additional families, we observed a P value of 0.015 for this variant. However, an association study of this single-nucleotide polymorphism (SNP) in unrelated Quebec-wide samples was not significant. We also identified an SNP (rs11646677) in the same region, which was significantly associated with a low HDL-C (P=0.016) in the SLSJ study sample. In addition, RT-PCR results from cultured cells showed a significant difference in the expression of CHST6 and KIAA1576, another gene in the region. Our data constitute additional evidence for a locus on chromosome 16q23-24 that affects HDL-C levels in two independent French-Canadian studies.
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Ghasabeh TH, Firoozrai M, Zonouz AE, Radmehr H, Zavarehee A, Paoli M. One common polymorphism of cholesteryl ester transfer protein gene in Iranian subjects with and without primary hypertriglyceridemia. Pak J Biol Sci 2009; 10:4224-9. [PMID: 19086575 DOI: 10.3923/pjbs.2007.4224.4229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Primary hypertriglyceridemia is considered to be a major risk factor for pancreatitis, atherosclerosis and coronary heart disease. Cholesteryl ester transfer protein gene polymorphisms known to be associated with changes in lipid levels. This study was performed by using polymerase chain reaction and restriction fragment length polymorphisms. Genotype distribution and allelic frequencies of polymorphism were determined and compared in primary hypertriglyceridemic and normotriglyceridemic subjects. The results showed that plasma cholesteryl ester transfer protein activity was significantly higher in primary hypertriglyceridemia than in controls (p = 0.001). In this study all individuals with B2B2 genotype had lower plasma cholesteryl ester transfer protein activity, higher high-density lipoprotein than B1B1 and B1B2 genotypes, whereas triglyceride was significantly decreased in this genotype. The genotype and allelic frequencies for this polymorphism differed significantly between primary hypertriglyceridemic patients and controls (p = 0.014 and p = 0.027, respectively). In both groups, CETP Taq 1B polymorphism (presence of B2 allele) correlated significantly with HDL-C (r = 0.207 and 0.300 in control and patient groups, respectively) and CETP activity (r = -0.193 for controls and r = -0.132 for patients). Taq 1B polymorphism of cholesteryl ester transfer protein gene was associated with changes in lipids profile and plasma cholesteryl ester transfer protein activity in the selected population.
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Affiliation(s)
- Taghi Hassanzadeh Ghasabeh
- Department of Clinical Biochemistry, School of Medicine, Hamedan University of Medical Sciences, Hamedan, Iran
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Association between cholesteryl ester transfer protein Taq1B polymorphism with lipid levels in primary hyperlipidemic patients. EUR J LIPID SCI TECH 2008. [DOI: 10.1002/ejlt.200700101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Pei WD, Zhang YH, Sun YH, Gu YC, Wang YF, Zhang CY, Zhang J, Liu LS, Hui RT, Liu YQ, Yang YJ. Apolipoprotein E polymorphism influences lipid phenotypes in Chinese families with familial combined hyperlipidemia. Circ J 2007; 70:1606-10. [PMID: 17127808 DOI: 10.1253/circj.70.1606] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Apolipoprotein E (apoE) polymorphism is associated with changes in the lipoprotein profile of individuals with familial combined hyperlipidemia (FCHL), but its effects on the lipoprotein profiles of members of Chinese families with FCHL remain uncertain. METHODS AND RESULTS 43 FCHL families (n=449) and 9 normolipidemic families (n=73) were recruited to assess the influence of apoE polymorphism on plasma lipids. The relative frequency of the epsilon4 allele in affected and unaffected FCHL relatives, spouses and normolipidemic members was 13.8%, 5.3%, 9.1% and 6.8%, respectively, with a significantly higher frequency in affected FCHL relatives, compared with unaffected FCHL relatives or normolipidemic members (p=0.0002 or p=0.029). In FCHL relatives, the apoE4 subset (E4/4 and E4/3) exhibited significantly higher levels of apoB, total cholesterol and low-density lipoprotein-cholesterol (LDL-C) than did the apoE3 (E3/3) subset, especially in women (all p<0.05), and there was significant elevation of LDL-C concentrations in men only (p<0.05). In men, the apoE2 (E3/2) subset indicated a decreased level of apoB and increased apoA1 compared with those in the apoE3 subset (p<0.05). CONCLUSIONS ApoE polymorphism appears to be associated with variance of the lipoprotein phenotype in Chinese families with FCHL.
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Affiliation(s)
- Wei-Dong Pei
- Division of Cardiology, Cardiovascular Institute and Fu Wai Heart Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
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van der Vleuten GM, Isaacs A, Zeng WW, ter Avest E, Talmud PJ, Dallinga-Thie GM, van Duijn CM, Stalenhoef AFH, de Graaf J. Haplotype analyses of the APOA5 gene in patients with familial combined hyperlipidemia. Biochim Biophys Acta Mol Basis Dis 2006; 1772:81-8. [PMID: 17157483 DOI: 10.1016/j.bbadis.2006.10.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Revised: 10/15/2006] [Accepted: 10/20/2006] [Indexed: 11/18/2022]
Abstract
BACKGROUND Familial combined hyperlipidemia (FCH) is the most common genetic lipid disorder with an undefined genetic etiology. Apolipoprotein A5 gene (APOA5) variants were previously shown to contribute to FCH. The aim of the present study was to evaluate the association of APOA5 variants with FCH and its related phenotypes in Dutch FCH patients. Furthermore, the effects of variants in the APOA5 gene on carotid intima-media thickness (IMT) and cardiovascular disease (CVD) were examined. MATERIALS AND METHODS The study population consisted of 36 Dutch families, including 157 FCH patients. Two polymorphisms in the APOA5 gene (-1131T>C and S19W) were genotyped. RESULTS Haplotype analysis of APOA5 showed an association with FCH (p=0.029), total cholesterol (p=0.031), triglycerides (p<0.001), apolipoprotein B (p=0.011), HDL-cholesterol (p=0.013), small dense LDL (p=0.010) and remnant-like particle cholesterol (p=0.001). Compared to S19 homozygotes, 19W carriers had an increased risk of FCH (OR=1.6 [1.0-2.6]; p=0.026) and a more atherogenic lipid profile, reflected by higher triglyceride (+22%) and apolipoprotein B levels (+5%), decreased HDL-cholesterol levels (-7%) and an increased prevalence of small dense LDL (16% vs. 26%). In carriers of the -1131C allele, small dense LDL was more prevalent than in -1131T homozygotes (29% vs. 16%). No association of the APOA5 gene with IMT and CVD was evident. CONCLUSION In Dutch FCH families, variants in the APOA5 gene are associated with FCH and an atherogenic lipid profile.
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Affiliation(s)
- Gerly M van der Vleuten
- Department of Medicine, Division of General Internal Medicine, 463, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
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Abstract
PURPOSE OF REVIEW To provide an overview of recent advances that have defined the first putative genes behind familial combined hyperlipidemia, the most common genetic dyslipidemia and a major risk factor for early coronary heart disease. RECENT FINDINGS The first locus for familial combined hyperlipidemia on 1q21-23 revealed a gene encoding a transcription factor critical in lipid and glucose metabolism, USF1. All the associated variants represent noncoding single nucleotide polymorphisms, one of which affects the binding site of nuclear proteins with a putative effect on transcript levels of USF1. Transcript analyses of fat biopsies have exposed risk-allele related changes in the downstream genes. Another recent clue to the molecular pathogenesis of familial combined hyperlipidemia is the association of the high triglyceride trait with the APOA5 gene, located on 11q. More familial combined hyperlipidemia genes are expected to be found, since linkage evidence exists for additional loci on 16q24 and 20q12-q13.1. SUMMARY Genetic research of familial combined hyperlipidemia families has revealed several linked loci guiding to susceptibility genes. The USF1 transcription factor is the major gene underlying the 1q21-23 linkage. Modifying genes, especially influencing the high triglyceride trait, include APOC3 and APOA5, the latter representing a downstream target of USF1 and implying a USF1-dependent pathway in the molecular pathogenesis of dyslipidemias.
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Affiliation(s)
- Jussi Naukkarinen
- Department of Molecular Medicine, National Public Health Institute, Helsinki, Finland
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11
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Abstract
Familial combined hyperlipidemia (FCHL) constitutes a substantial risk factor for atherosclerosis since it is observed in about 20% of coronary heart disease (CHD) patients under 60 years. FCHL, characterized by elevated levels of total cholesterol (TC) and triglycerides (TGs), or both, is also one of the most common familial hyperlipidemias with a prevalence of 1%-6% in Western populations. Numerous studies have been performed to identify genes contributing to FCHL. The recent linkage and association studies and their replications are beginning to elucidate the genetic variations underlying the susceptibility to FCHL. Three chromosomal regions on 1q21-23, 11p and 16q22-24.1 have been replicated in different study samples, offering targets for gene hunting. In addition, several candidate gene studies have replicated the influence of the lipoprotein lipase (LPL) gene and apolipoprotein A1/C3/A4/A5 (APOA1/C3/A4/A5) gene cluster in FCHL. Recently, the linked region on chromosome 1q21 was successfully fine-mapped and the upstream transcription factor 1 (USF1) gene identified as the underlying gene for FCHL. This finding has now been replicated in independent FCHL samples. However, the total number of variants, the risk related to each variant and their relative contributions to the disease susceptibility are not known yet.
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Affiliation(s)
- Elina Suviolahti
- Department of Human Genetics, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA 90095-7088, USA
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Naukkarinen J, Gentile M, Soro-Paavonen A, Saarela J, Koistinen HA, Pajukanta P, Taskinen MR, Peltonen L. USF1 and dyslipidemias: converging evidence for a functional intronic variant. Hum Mol Genet 2005; 14:2595-605. [PMID: 16076849 DOI: 10.1093/hmg/ddi294] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Upstream transcription factor 1 (USF1), the first gene associated with familial combined hyperlipidemia (FCHL), regulates numerous genes of glucose and lipid metabolism. Phenotypic overlap between FCHL, type 2 diabetes and the metabolic syndrome makes this gene an intriguing candidate in the disease process of these traits as well. As no disease-associated mutations in the coding region of USF1 have been identified, we addressed the functional role of intronic single nucleotide polymorphisms (SNPs) which define the FCHL-risk alleles of USF1, and identified that a 20 bp DNA sequence, containing the critical intronic SNP, binds nuclear protein(s), representing a likely transcriptional regulatory element. This functional role is further supported by the differential expression of USF1-regulated genes in fat biopsy between individuals carrying different allelic variants of USF1. Importantly, apolipoprotein E (APOE) is the most downregulated gene in the risk individuals, linking the potential risk alleles of USF1 with the impaired APOE-dependent catabolism of atherogenic lipoprotein particles.
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Affiliation(s)
- Jussi Naukkarinen
- Department of Molecular Medicine, National Public Health Institute, Finland
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Gagnon F, Jarvik GP, Badzioch MD, Motulsky AG, Brunzell JD, Wijsman EM. Genome scan for quantitative trait loci influencing HDL levels: evidence for multilocus inheritance in familial combined hyperlipidemia. Hum Genet 2005; 117:494-505. [PMID: 15959807 DOI: 10.1007/s00439-005-1338-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2004] [Accepted: 04/27/2005] [Indexed: 11/25/2022]
Abstract
Several genome scans in search of high-density lipoprotein (HDL) quantitative trait loci (QTLs) have been performed. However, to date the actual identification of genes implicated in the regulation of common forms of HDL abnormalities remains unsuccessful. This may be due, in part, to the oligogenic and multivariate nature of HDL regulation, and potentially, pleiotropy affecting HDL and other lipid-related traits. Using a Bayesian Markov Chain Monte Carlo (MCMC) approach, we recently provided evidence of linkage of HDL level variation to the APOA1-C3-A4-A5 gene complex, in familial combined hyperlipidemia pedigrees, with an estimated number of two to three large QTLs remaining to be identified. We also presented results consistent with pleiotropy affecting HDL and triglycerides at the APOA1-C3-A4-A5 gene complex. Here we use the same MCMC analytic strategy, which allows for oligogenic trait models, as well as simultaneous incorporation of covariates, in the context of multipoint analysis. We now present results from a genome scan in search for the additional HDL QTLs in these pedigrees. We provide evidence of linkage for additional HDL QTLs on chromosomes 3p14 and 13q32, with results on chromosome 3 further supported by maximum parametric and variance component LOD scores of 3.0 and 2.6, respectively. Weaker evidence of linkage was also obtained for 7q32, 12q12, 14q31-32 and 16q23-24.
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Affiliation(s)
- France Gagnon
- Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada
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Huertas-Vázquez A, del Rincón JP, Canizales-Quinteros S, Riba L, Vega-Hernández G, Ramírez-Jiménez S, Aurón-Gómez M, Gómez-Pérez FJ, Aguilar-Salinas CA, Tusié-Luna MT. Contribution of Chromosome 1q21-q23 to Familial Combined Hyperlipidemia in Mexican Families. Ann Hum Genet 2004; 68:419-27. [PMID: 15469419 DOI: 10.1046/j.1529-8817.2003.00116.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Familial combined hyperlipidemia (FCHL) is the most common familial dyslipidemia, with a prevalence of 1-2% in the general population. A major locus for FCHL has been mapped to chromosome 1q21-q23 in Finnish, Chinese, German and US families. We studied seven extended Mexican families with 153 members, including 64 affected subjects. A total of 11 markers were genotyped, including D1S104 which has been linked to FCHL in other studies. Two point linkage analysis for the FCHL phenotype, and for the elevated triglyceride (TG) trait, allowing for heterogeneity, gave a maximum HLOD of 1.67 (alpha = 0.49) and 1.93 (alpha = 0.43) at D1S2768 (2.69 cM proximal to D1S104) respectively. Heterogeneity and non-parametric (NPL) multipoint analyses for the FCHL phenotype and the TG trait showed maximum HLODs of 1.27 (alpha = 0.46) and 1.64 (alpha = 0.38), and NPLs of 4.00 (P = 0.0001) and 3.68 (P = 0.0003) near D1S2768, respectively. In addition, analysis of four candidate genes putatively involved in the expression of FCHL showed no evidence of linkage for the LCAT gene or the APOA1/C3/A4/A5 gene cluster. However, we cannot exclude the participation of these genes, or the LIPC and LPL genes, as minor susceptibility loci in the expression of FCHL, or the TG or elevated total cholesterol (TC) traits in our families. In conclusion, our data confirm the involvement of a major susceptibility locus on chromosome 1q21-q23 in FCHL Mexican families, consistent with findings in other populations.
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Affiliation(s)
- A Huertas-Vázquez
- Unidad de Biología Molecular y Medicina Genómica del Instituto de Investigaciones Biomédicas de la Universidad Nacional Autónoma de México y del Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City
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Ayyobi AF, Brunzell JD. Lipoprotein distribution in the metabolic syndrome, type 2 diabetes mellitus, and familial combined hyperlipidemia. Am J Cardiol 2003; 92:27J-33J. [PMID: 12957324 DOI: 10.1016/s0002-9149(03)00613-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Metabolic abnormalities associated with the metabolic syndrome are also present in patients with type 2 diabetes mellitus and in those with familial combined hyperlipidemia (FCHL). These abnormalities include central obesity, insulin resistance with hyperinsulinemia, hypertension, increased plasma triglycerides, and decreased high-density lipoprotein cholesterol levels. Other characteristics associated with FCHL include the presence of small, dense low-density lipoprotein cholesterol and increased apolipoprotein B. Patients with these abnormalities are at an increased risk for premature coronary artery disease. Treatment of the dyslipidemia associated with type 2 diabetes and FCHL with a combination of a statin and a thiazolidinedione or niacin offers the most comprehensive modality to correct the various lipid abnormalities.
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Affiliation(s)
- Amir F Ayyobi
- Department of Medicine, Division of Metabolism, Endocrinology and Nutrition, University of Washington, Seattle, Washington 98195, USA
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Soro A, Jauhiainen M, Ehnholm C, Taskinen MR. Determinants of low HDL levels in familial combined hyperlipidemia. J Lipid Res 2003; 44:1536-44. [PMID: 12777471 DOI: 10.1194/jlr.m300069-jlr200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In familial combined hyperlipidemia (FCHL), affected family members frequently have reduced levels of HDL cholesterol, in addition to elevated levels of total cholesterol and/or triglycerides (TGs). In the present study, we focused on those determinants that are important regulators of HDL cholesterol levels in FCHL, and measured postheparin plasma activities of hepatic lipase (HL), lipoprotein lipase, cholesterol ester transfer protein, and phospholipid transfer protein (PLTP) in 228 subjects from 49 FCHL families. In affected family members (n = 88), the levels of HDL cholesterol, HDL2 cholesterol, HDL3 cholesterol, and apolipoprotein A-I were lower than in unaffected family members (n = 88) or spouses (n = 52). The main change was the reduction of HDL2 cholesterol by 25.4% in affected family members (P < 0.001 vs. unaffected family members; P = 0.003 vs. spouses). Affected family members had higher HL activity than unaffected family members (P = 0.001) or spouses (P = 0.013). PLTP activity was higher in affected than unaffected family members (P = 0.025). In univariate correlation analysis, a strong negative correlation was observed between HL activity and HDL2 cholesterol (r = -0.339, P < 0.001). Multivariate regression analysis demonstrated that gender, HL activity, TG, and body mass index have independent contributions to HDL2 cholesterol levels. We suggest that in FCHL, TG enrichment of HDL particles and enhanced HL activity lead to the reduction of HDL cholesterol and HDL2 cholesterol.
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Affiliation(s)
- Aino Soro
- Department of Medicine, University of Helsinki, Finland
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Aouizerat BE, Kulkarni M, Heilbron D, Drown D, Raskin S, Pullinger CR, Malloy MJ, Kane JP. Genetic analysis of a polymorphism in the human apoA-V gene: effect on plasma lipids. J Lipid Res 2003; 44:1167-73. [PMID: 12671030 DOI: 10.1194/jlr.m200480-jlr200] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recent discovery and characterization of APOAV suggests a role in metabolism of triglyceride (TG)-rich lipoproteins. Previously, variation at the APOAV locus was shown to modestly influence plasma TGs in normolipidemic samples. The aims of this study were to assess the effects of a polymorphism in APOAV (T-1131C) in terms of its frequency among three dyslipidemic populations and a control population, differences of allele frequency across available ethnic groups, and associations with specific lipoprotein TG and cholesterol compartments. We found a striking elevation in the frequency of the rare allele in a Chinese population (P = 0.0002) compared with Hispanic and European populations. The rare allele of the polymorphism was associated with elevated plasma TG (P = 0.012), VLDL cholesterol (P = 0.0007), and VLDL TG (P = 0.012), LDL TG (P = 0.003), and HDL TG (P = 0.016). Linear regression models predict that possession of the rare allele elevates plasma TG by 21 mg/dl (P = 0.009) and VLDL cholesterol by 8 mg/dl (P = 0.0001), and reduces HDL cholesterol by 2 mg/dl (P = 0.017). The association of the polymorphism with altered lipoprotein profiles was observed in combined hyperlipidemia, hypoalphalipoproteinemia, and hyperalphalipoproteinemia, and in controls. These findings indicate that APOAV is an important determinant of plasma TG and lipoprotein cholesterol, and is potentially a risk factor for cardiovascular disease.
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Affiliation(s)
- Bradley E Aouizerat
- Department of Physiological Nursing, University of California San Francisco, San Francisco, CA 94143, USA.
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Pajukanta P, Allayee H, Krass KL, Kuraishy A, Soro A, Lilja HE, Mar R, Taskinen MR, Nuotio I, Laakso M, Rotter JI, de Bruin TWA, Cantor RM, Lusis AJ, Peltonen L. Combined analysis of genome scans of dutch and finnish families reveals a susceptibility locus for high-density lipoprotein cholesterol on chromosome 16q. Am J Hum Genet 2003; 72:903-17. [PMID: 12638083 PMCID: PMC1180353 DOI: 10.1086/374177] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2002] [Accepted: 01/08/2003] [Indexed: 12/31/2022] Open
Abstract
Several genomewide screens have been performed to identify novel loci predisposing to unfavorable serum lipid levels and coronary heart disease (CHD). We hypothesized that the accumulating data of these screens in different study populations could be combined to verify which of the identified loci truly harbor susceptibility genes. The power of this strategy has recently been demonstrated with other complex diseases, such as inflammatory bowel disease and asthma. We assessed the largely unknown genetic background of CHD by investigating the most common dyslipidemia predisposing to CHD, familial combined hyperlipidemia (FCHL), affecting 1%-2% of Western populations and 10%-20% of families with premature CHD. To be able to perform a combined data analysis, we unified the diagnostic criteria for FCHL and its component traits and combined the data from two genomewide scans performed in two populations, the Finns and the Dutch. As a result of our pooled data analysis, we identified three chromosomal regions, on chromosomes 2p25.1, 9p23, and 16q24.1, exceeding the statistical significance level of a LOD score >2.0. The 2p25.1 region was detected for the FCHL trait, and the 9p23 and 16q24.1 regions were detected for the low high-density lipoprotein cholesterol (HDL-C) trait. In addition, the previously recognized 1q21 region also obtained additional support in the other study sample, when the triglyceride trait was used. Analysis of the 16q24.1 region resulted in a statistically significant LOD score of 3.6 when the data from Finnish families with low HDL-C were included in the analysis. To search for the underlying gene in the 16q24.1 region, we investigated a novel functional and positional candidate gene, helix/forkhead transcription factor (FOXC2), by sequencing and by genotyping of two single-nucleotide polymorphisms in the families.
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Affiliation(s)
- Päivi Pajukanta
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Hooman Allayee
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Kelly L. Krass
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Ali Kuraishy
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Aino Soro
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Heidi E. Lilja
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Rebecca Mar
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Marja-Riitta Taskinen
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Ilpo Nuotio
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Markku Laakso
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Jerome I. Rotter
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Tjerk W. A. de Bruin
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Rita M. Cantor
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Aldons J. Lusis
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
| | - Leena Peltonen
- Departments of Human Genetics, Microbiology and Molecular Genetics, Medicine, and Pediatrics and Molecular Biology Institute, David Geffen School of Medicine at the University of California–Los Angeles, and Division of Medical Genetics, Steven Spielberg Pediatric Research Center and Cedars-Sinai Research Institute, Los Angeles; Department of Medicine, Helsinki University Central Hospital, and Department of Molecular Medicine, National Public Health Institute, and Department of Medical Genetics, University of Helsinki, Helsinki; Department of Medicine, Turku University Central Hospital, Turku, Finland; Department of Medicine, Kuopio University Central Hospital, Kuopio, Finland; and Department of Medicine and the Cardiovascular Research Institute Maastricht, Academic Hospital, Maastricht, the Netherlands
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19
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Eurlings PMH, van der Kallen CJH, Geurts JMW, Flavell DM, de Bruin TWA. Identification of the PPARA locus on chromosome 22q13.3 as a modifier gene in familial combined hyperlipidemia. Mol Genet Metab 2002; 77:274-81. [PMID: 12468272 DOI: 10.1016/s1096-7192(02)00174-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Familial combined hyperlipidemia (FCHL) is a common genetic lipid disorder that is present in 10% of patients with premature coronary artery disease (CAD). It was the objective of the present study to evaluate the possible involvement of the PPARA locus in the pathophysiology of FCHL. Mutation detection analyses of the six coding PPARA exons resulted in the identification of four novel variants, [C/T] intron 3, S234G, [G/A] intron 5, and [C/A] 3(') UTR in three FCHL probands, whereas no novel variants were identified in spouses. In a case-control study, markers D22S275 and D22S928 were shown not to be associated with FCHL. However, D22S928, mapped within 1Mb of the PPARA gene, was shown to have a modifying effect on plasma apoCIII concentrations (P=0.011) and the combined hyperlipidemic FCHL phenotype (P=0.038). In addition two PPARA polymorphisms in intron 2 and 7 were studied, but these were not associated with FCHL. The frequency of the L162V variant was less in FCHL probands (1.98%) compared to that in spouses (4.84%). These results clearly demonstrate the genetically complex nature of FCHL and identify the PPARA gene as a modifier of the FCHL phenotype.
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Affiliation(s)
- Petra M H Eurlings
- Department of Internal Medicine, Laboratory of Molecular Metabolism and Endocrinology, Cardiovascular Research Institute Maastricht, University of Maastricht, PO Box 616, Maastricht, NL-6200 MD, The Netherlands.
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20
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Kwiterovich PO. Clinical relevance of the biochemical, metabolic, and genetic factors that influence low-density lipoprotein heterogeneity. Am J Cardiol 2002; 90:30i-47i. [PMID: 12419479 DOI: 10.1016/s0002-9149(02)02749-2] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Traditional risk factors for coronary artery disease (CAD) predict about 50% of the risk of developing CAD. The Adult Treatment Panel (ATP) III has defined emerging risk factors for CAD, including small, dense low-density lipoprotein (LDL). Small, dense LDL is often accompanied by increased triglycerides (TGs) and low high-density lipoprotein (HDL). An increased number of small, dense LDL particles is often missed when the LDL cholesterol level is normal or borderline elevated. Small, dense LDL particles are present in families with premature CAD and hyperapobetalipoproteinemia, familial combined hyperlipidemia, LDL subclass pattern B, familial dyslipidemic hypertension, and syndrome X. The metabolic syndrome, as defined by ATP III, incorporates a number of the components of these syndromes, including insulin resistance and intra-abdominal fat. Subclinical inflammation and elevated procoagulants also appear to be part of this atherogenic syndrome. Overproduction of very low-density lipoproteins (VLDLs) by the liver and increased secretion of large, apolipoprotein (apo) B-100-containing VLDL is the primary metabolic characteristic of most of these patients. The TG in VLDL is hydrolyzed by lipoprotein lipase (LPL) which produces intermediate-density lipoprotein. The TG in intermediate-density lipoprotein is hydrolyzed further, resulting in the generation of LDL. The cholesterol esters in LDL are exchanged for TG in VLDL by the cholesterol ester tranfer proteins, followed by hydrolysis of TG in LDL by hepatic lipase which produces small, dense LDL. Cholesterol ester transfer protein mediates a similar lipid exchange between VLDL and HDL, producing a cholesterol ester-poor HDL. In adipocytes, reduced fatty acid trapping and retention by adipose tissue may result from a primary defect in the incorporation of free fatty acids into TGs. Alternatively, insulin resistance may promote reduced retention of free fatty acids by adipocytes. Both these abnormalities lead to increased levels of free fatty acids in plasma, increased flux of free fatty acids back to the liver, enhanced production of TGs, decreased proteolysis of apo B-100, and increased VLDL production. Decreased removal of postprandial TGs often accompanies these metabolic abnormalities. Genes regulating the expression of the major players in this metabolic cascade, such as LPL, cholesterol ester transfer protein, and hepatic lipase, can modulate the expression of small, dense LDL but these are not the major defects. New candidates for major gene effects have been identified on chromosome 1. Regardless of their fundamental causes, small, dense LDL (compared with normal LDL) particles have a prolonged residence time in plasma, are more susceptible to oxidation because of decreased interaction with the LDL receptor, and enter the arterial wall more easily, where they are retained more readily. Small, dense LDL promotes endothelial dysfunction and enhanced production of procoagulants by endothelial cells. Both in animal models of atherosclerosis and in most human epidemiologic studies and clinical trials, small, dense LDL (particularly when present in increased numbers) appears more atherogenic than normal LDL. Treatment of patients with small, dense LDL particles (particularly when accompanied by low HDL and hypertriglyceridemia) often requires the use of combined lipid-altering drugs to decrease the number of particles and to convert them to larger, more buoyant LDL. The next critical step in further reduction of CAD will be the correct diagnosis and treatment of patients with small, dense LDL and the dyslipidemia that accompanies it.
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Affiliation(s)
- Peter O Kwiterovich
- Lipid Research Atherosclerosis Division, Departments of Pediatrics and Medicine, the Johns Hopkins University School of Medicine, University Lipid Clinic, Baltimore, Maryland 21205, USA.
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21
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Identification of differentially expressed genes in subcutaneous adipose tissue from subjects with familial combined hyperlipidemia. J Lipid Res 2002. [DOI: 10.1016/s0022-2275(20)30467-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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22
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Elbein SC, Hasstedt SJ. Quantitative trait linkage analysis of lipid-related traits in familial type 2 diabetes: evidence for linkage of triglyceride levels to chromosome 19q. Diabetes 2002; 51:528-35. [PMID: 11812765 DOI: 10.2337/diabetes.51.2.528] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Macrovascular disease is a major complication of type 2 diabetes. Epidemiological data suggest that the risk of macrovascular complications may predate the onset of hyperglycemia. Hypertriglyceridemia, low levels of HDL cholesterol, and an atherogenic profile characterize the insulin resistance/metabolic syndrome that is also prevalent among nondiabetic members of familial type 2 diabetic kindreds. To identify the genes for lipid-related traits, we first performed a 10-cM genome scan using 440 markers in 379 members of 19 multiplex families ascertained for two diabetic siblings (screening study). We then extended findings for three regions with initial logarithm of odds (LOD) scores >1.5 to an additional 23 families, for a total of 576 genotyped individuals (extended study). We found heritabilities for all lipid measures in the range of 0.31 to 0.52, similar to those reported by others in unselected families. However, we found the strongest evidence for linkage of triglyceride levels to chromosome 19q13.2, very close to the ApoC2/ApoE/ApoC1/ApoC4 gene cluster (LOD 2.56) in the screening study; the LOD increased to 3.16 in the extended study. Triglyceride-to-HDL cholesterol ratios showed slightly lower LOD scores (2.73, extended family) in this same location. Other regions with LOD scores >2.0 included HDL linkage to chromosome 1q21-q23, where susceptibility loci for both familial type 2 diabetes and familial combined hyperlipidemia have been mapped, and to chromosome 2q in the region of the NIDDM1 locus. Neither region showed stronger evidence for linkage in the extended studies, however. Our results suggest that genes in or near the ApoE/ApoC2/ApoC1/ApoC4 cluster on 19q13.2 may contribute to the commonly observed hypertriglyceridemia and low HDL seen in diabetic family members and their offspring, and thus may be a candidate locus for the insulin resistance syndrome.
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Affiliation(s)
- S C Elbein
- Department of Endocrinology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199, USA.
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23
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Pihlajamäki J, Austin M, Edwards K, Laakso M. A major gene effect on fasting insulin and insulin sensitivity in familial combined hyperlipidemia. Diabetes 2001; 50:2396-401. [PMID: 11574425 DOI: 10.2337/diabetes.50.10.2396] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The most common inherited dyslipidemia, familial combined hyperlipidemia (FCHL), is associated with insulin resistance. Whether insulin sensitivity in these families is inherited is not known. Therefore, we investigated the inheritance of insulin sensitivity in 352 nondiabetic family members from 37 families with FCHL, 105 of whom had undergone testing using the hyperinsulinemic-euglycemic clamp technique for the measurement of insulin sensitivity. First, complex segregation analysis of fasting insulin levels (both unadjusted and age-, age(2)-, and BMI-adjusted) was used for modeling of the variance in fasting insulin levels. In these analyses, Mendelian codominant inheritance (P = 0.320 for unadjusted and P = 0.295 for adjusted insulin values) was not rejected over the most general model and fit the data significantly better than the sporadic model (P < 0.001). Polygenic and environmental models were rejected (P < 0.001). The Mendelian codominant model explained 44 and 45% of the variance in unadjusted and adjusted fasting insulin levels, respectively. The proposed genotypes of this locus, based on segregation analysis, were associated with directly measured insulin sensitivity in 105 FCHL family members who underwent the hyperinsulinemic-euglycemic clamp (P < 0.001). These results provide evidence for a major gene regulating insulin sensitivity in FCHL families. Possible pleiotropic effects of this insulin sensitivity locus on dyslipidemias in FCHL remain to be elucidated.
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Affiliation(s)
- J Pihlajamäki
- Department of Medicine, University of Kuopio, Kuopio, Finland.
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24
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Eurlings PM, van der Kallen CJ, Geurts JM, van Greevenbroek MM, de Bruin TW. Genetic dissection of familial combined hyperlipidemia. Mol Genet Metab 2001; 74:98-104. [PMID: 11592807 DOI: 10.1006/mgme.2001.3232] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Familial combined hyperlipidemia (FCHL) is the most common genetic hyperlipidemia in man. FCHL is characterized by familial clustering of hyperlipidemia and clinical manifestations of premature coronary heart disease, i.e., before the age of 60. Although FCHL was delineated about 25 years ago, at present the FCHL phenotype and its complex genetics are not fully understood. Initially, the familial aggregation of high plasma total cholesterol and triglyceride levels, with a bimodal distribution of triglycerides, was taken as evidence of a dominant mode of inheritance. However, it is now clear that the genetics of FCHL is more complex, and it has been suggested that FCHL is heterogeneous. Several approaches can be taken to identify genes contributing to the disease phenotype in complex genetic disorders either by studying the disease in the human situation or by using animal models. Recent reports have shown that a combination of genetic linkage studies, association studies, and differential gene expression studies provides a useful tool for the genetic dissection of complex diseases. Therefore, the genetic strategies that will be used to dissect the genetic background of FCHL are reviewed.
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Affiliation(s)
- P M Eurlings
- Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands
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25
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Breslow JL. Genetics of lipoprotein abnormalities associated with coronary artery disease susceptibility. Annu Rev Genet 2001; 34:233-254. [PMID: 11092828 DOI: 10.1146/annurev.genet.34.1.233] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Coronary heart disease is a complex genetic disease with many genes involved, environmental influences, and important gene-environment interactions. This review discusses the genetic basis of the principal lipoprotein abnormalities associated with coronary heart disease susceptibility in the general population. Individual sections discuss genes regulating LDL cholesterol, HDL cholesterol, and triglyceride levels. A section is included on the effects of the common apo E genetic variation on lipoprotein levels, as well as sections on the genetic regulation of lipoprotein(a) levels, genes regulating the inverse relationship between triglyceride-rich lipoproteins and HDL cholesterol levels, and our current understanding of the genetic basis of familial combined hyperlipidemia. It is clear that the field has progressed, with early studies focused mainly on the association of candidate gene RFLPs with phenotypes, later studies of candidate genes in both parametric and nonparametric linkage studies, and now more and more studies combining linkage analysis with genome scans to identify new loci that influence lipoprotein phenotypes. The future should provide us with the capability to perform reasonable genetic profiling for lipoprotein abnormalities associated with coronary heart disease susceptibility.
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Affiliation(s)
- J L Breslow
- Laboratory of Biochemical Genetics and Metabolism, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
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26
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van Greevenbroek MM, van der Kallen CJ, Geurts JM, Janssen RG, Buurman WA, de Bruin TW. Soluble receptors for tumor necrosis factor-alpha (TNF-R p55 and TNF-R p75) in familial combined hyperlipidemia. Atherosclerosis 2000; 153:1-8. [PMID: 11058695 DOI: 10.1016/s0021-9150(00)00375-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We investigated the potential role of the 75 kD receptor for tumor necrosis factor-alpha (TNF-alpha) (TNFRSF1B, located on chromosome 1 band p36.2) as a modifier gene in familial combined hyperlipidemia (FCH), based on previous linkage and association data. Age-corrected values for the soluble (s) extracellular domain of TNF-R p75 were lower in 156 well-characterized hyperlipidemic (HL) FCH relatives than in 168 normolipidemic (NL) relatives (P<0.01). Plasma concentrations of the soluble domain of the 55 kD receptor (sTNF-R p55, the other TNF-alpha receptor) did not differ between HL and NL relatives. In conditional logistic regression analysis, plasma sTNF-R p75 concentration was the only non-lipid variable that contributed significantly to prediction of affected FCH status (regression coefficient=-0.413, P=0.01). The present findings have potentially important diagnostic and therapeutic implications in FCH.
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Affiliation(s)
- M M van Greevenbroek
- Laboratory for Molecular Metabolism and Endocrinology/UNS 50, Department of Internal Medicine, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, PO Box 616, 6200 MD, Maastricht, The Netherlands.
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27
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Escolà-Gil JC, Julve J, Marzal-Casacuberta À, Ordóñez-Llanos J, González-Sastre F, Blanco-Vaca F. Expression of human apolipoprotein A-II in apolipoprotein E-deficient mice induces features of familial combined hyperlipidemia. J Lipid Res 2000. [DOI: 10.1016/s0022-2275(20)33441-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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28
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Peelman F, Vandekerckhove J, Rosseneu M. Structure and function of lecithin cholesterol acyl transferase: new insights from structural predictions and animal models. Curr Opin Lipidol 2000; 11:155-60. [PMID: 10787177 DOI: 10.1097/00041433-200004000-00008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The enzyme lecithin cholesterol acyl transferase is responsible for the synthesis of most of the cholesteryl esters in plasma, and therefore plays a key role in lipoprotein metabolism. The relationship between the structure and function of lecithin cholesterol acyl transferase has been extensively studied in the past years, and new data appeared in 1999 documenting the substrate specificity and physiological role of lecithin cholesterol acyl transferase. The discovery of natural mutants, together with the proposal of a three-dimensional model for the enzyme, has provided new tools to unravel the function of specific residues of lecithin cholesterol acyl transferase. The use of transgenic animals and the production of knock-out lecithin cholesterol acyl transferase mice has further contributed to the understanding of the lecithin cholesterol acyl transferase 'in vivo' function. Evidence for a protective role of lecithin cholesterol acyl transferase against the development of atherosclerosis through the hydrolysis of oxidized lipids was recently proposed. Lecithin cholesterol acyl transferase patterns in several pathologies were further clarified. These newer developments are reviewed here.
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Affiliation(s)
- F Peelman
- Department of Biochemistry, Faculty of Medicine, Universiteit Gent, Belgium
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29
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Aouizerat BE, Allayee H, Cantor RM, Davis RC, Lanning CD, Wen PZ, Dallinga-Thie GM, de Bruin TW, Rotter JI, Lusis AJ. A genome scan for familial combined hyperlipidemia reveals evidence of linkage with a locus on chromosome 11. Am J Hum Genet 1999; 65:397-412. [PMID: 10417282 PMCID: PMC1377938 DOI: 10.1086/302490] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Familial combined hyperlipidemia (FCHL) is a common familial lipid disorder characterized by a variable pattern of elevated levels of plasma cholesterol and/or triglycerides. It is present in 10%-20% of patients with premature coronary heart disease. The genetic etiology of the disease, including the number of genes involved and the magnitude of their effects, is unknown. Using a subset of 35 Dutch families ascertained for FCHL, we screened the genome, with a panel of 399 genetic markers, for chromosomal regions linked to genes contributing to FCHL. The results were analyzed by use of parametric-linkage methods in a two-stage study design. Four loci, on chromosomes 2p, 11p, 16q, and 19q, exhibited suggestive evidence for linkage with FCHL (LOD scores of 1.3-2.6). Markers within each of these regions were then examined in the original sample and in additional Dutch families with FCHL. The locus on chromosome 2 failed to show evidence for linkage, and the loci on chromosome 16q and 19q yielded only equivocal or suggestive evidence for linkage. However, one locus, near marker D11S1324 on the short arm of human chromosome 11, continued to show evidence for linkage with FCHL, in the second stage of this design. This region does not contain any strong candidate genes. These results provide evidence for a candidate chromosomal region for FCHL and support the concept that FCHL is complex and heterogeneous.
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Affiliation(s)
- B E Aouizerat
- Departments of 1Microbiology and Molecular Genetics, Medicine, Human Genetics, Molecular Biology Institute, University of California, UCLA School of Medicine Los Angeles, CA 90095-1679, USA
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