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Lanktree MB, Anand SS, Yusuf S, Hegele RA. Comprehensive Analysis of Genomic Variation in the
LPA
Locus and Its Relationship to Plasma Lipoprotein(a) in South Asians, Chinese, and European Caucasians. ACTA ACUST UNITED AC 2010; 3:39-46. [DOI: 10.1161/circgenetics.109.907642] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Functional copy number variation in the apolipoprotein(a) gene (
LPA
) underlies a variable number of protein kringle domains repeated in tandem in the lipoprotein(a) [Lp(a)] particle. Genomic analysis of
LPA
, including both single-nucleotide polymorphisms (SNPs) and kringle IV type 2 (KIV-2) copy number, has yet to be performed.
Methods and Results—
First, we genotyped 49 SNPs within 100 kb of
LPA
in a multiethnic sample comprising South Asians (n=330), Chinese (n=304), and European Caucasians (n=272). Second, using quantitative polymerase chain reaction, we estimated the KIV-2 copy number in each sample. European Caucasians had the lowest KIV-2 copy number but displayed the strongest correlation between KIV-2 copy number and plasma Lp(a) concentration (
r
s
=−0.31,
P
=4.2�10
−7
). SNP rs10455872, only prevalent in European Caucasians, was strongly associated with both plasma Lp(a) concentration (
P
=4.2�10
−29
) and KIV-2 copy number (
P
=7.2�10
−5
).
LPA
SNP rs6415084, within the same haplotype block as the KIV-2 variation, was significantly associated with both Lp(a) concentration and KIV-2 copy number in the same direction in all 3 ethnicities [Lp(a),
P
=5.3�10
−7
; KIV-2,
P
=2.6�10
−4
]. SNPs and KIV-2 copy number together explain a larger proportion of variation in plasma Lp(a) concentrations in European Caucasians (36%) than in Chinese (27%) or South Asians (21%).
Conclusions—
LPA
SNPs are in linkage disequilibrium with KIV-2 copy number, but KIV-2 copy number explains an increment in plasma Lp(a) variation over SNPs alone. Thus, both SNPs and KIV-2 copy number should be included in future genetic epidemiology studies of Lp(a).
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Affiliation(s)
- Matthew B. Lanktree
- From the Departments of Medicine and Biochemistry (M.B.L., R.A.H.), Robarts Research Institute and Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada; Population Health Research Institute (S.S.A., S.Y.), Hamilton Health Sciences, and Departments of Medicine and Clinical Epidemiology (S.S.A., S.Y.), McMaster University, Hamilton, Ontario, Canada
| | - Sonia S. Anand
- From the Departments of Medicine and Biochemistry (M.B.L., R.A.H.), Robarts Research Institute and Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada; Population Health Research Institute (S.S.A., S.Y.), Hamilton Health Sciences, and Departments of Medicine and Clinical Epidemiology (S.S.A., S.Y.), McMaster University, Hamilton, Ontario, Canada
| | - Salim Yusuf
- From the Departments of Medicine and Biochemistry (M.B.L., R.A.H.), Robarts Research Institute and Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada; Population Health Research Institute (S.S.A., S.Y.), Hamilton Health Sciences, and Departments of Medicine and Clinical Epidemiology (S.S.A., S.Y.), McMaster University, Hamilton, Ontario, Canada
| | - Robert A. Hegele
- From the Departments of Medicine and Biochemistry (M.B.L., R.A.H.), Robarts Research Institute and Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada; Population Health Research Institute (S.S.A., S.Y.), Hamilton Health Sciences, and Departments of Medicine and Clinical Epidemiology (S.S.A., S.Y.), McMaster University, Hamilton, Ontario, Canada
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Cardoso-Saldaña G, De La Peña-Díaz A, Zamora-González J, Gomez-Ortega R, Posadas-Romero C, Izaguirre-Avila R, Malvido-Miranda E, Morales-Anduaga ME, Angles-Cano E. Ethnicity and lipoprotein(a) polymorphism in Native Mexican populations. Ann Hum Biol 2006; 33:202-12. [PMID: 16684693 PMCID: PMC1940268 DOI: 10.1080/03014460500520006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND Lp(a) is a lipoparticle of unknown function mainly present in primates and humans. It consists of a low-density lipoprotein and apo(a), a polymorphic glycoprotein. Apo(a) shares sequence homology and fibrin binding with plasminogen, inhibiting its fibrinolytic properties. Lp(a) is considered a link between atherosclerosis and thrombosis. Marked inter-ethnic differences in Lp(a) concentration related to the genetic polymorphism of apo(a) have been reported in several populations. AIM The study examined the structural and functional features of Lp(a) in three Native Mexican populations (Mayos, Mazahuas and Mayas) and in Mestizo subjects. METHODS We determined the plasma concentration of Lp(a) by immunonephelometry, apo(a) isoforms by Western blot, Lp(a) fibrin binding by immuno-enzymatic assay and short tandem repeat (STR) polymorphic marker genetic analysis by capillary electrophoresis. RESULTS Mestizos presented the less skewed distribution and the highest median Lp(a) concentration (13.25 mg dL(-1)) relative to Mazahuas (8.2 mg dL(-1)), Mayas (8.25 mg dL(-1)) and Mayos (6.5 mg dL(-1)). Phenotype distribution was different in Mayas and Mazahuas as compared with the Mestizo group. The higher Lp(a) fibrin-binding capacity was found in the Maya population. There was an inverse relationship between the size of apo(a) polymorphs and both Lp(a) levels and Lp(a) fibrin binding. CONCLUSION There is evidence of significative differences in Lp(a) plasma concentration and phenotype distribution in the Native Mexican and the Mestizo group.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Eduardo Angles-Cano
- Hémostase, bio-ingénierie et remodelage cardiovasculaires
INSERM : U698Université Denis Diderot - Paris VIIChu Xavier Bichat
46, Rue Henri Huchard
75877 PARIS CEDEX 18,FR
- * Correspondence should be adressed to: Eduardo Angles-Cano
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