1
|
Bertolini S, Pisciotta L, Fasano T, Rabacchi C, Calandra S. The study of familial hypercholesterolemia in Italy: A narrative review. ATHEROSCLEROSIS SUPP 2017; 29:1-10. [DOI: 10.1016/j.atherosclerosissup.2017.07.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
2
|
Mollaki V, Drogari E. Genetic causes of monogenic familial hypercholesterolemia in the Greek population: Lessons, mistakes, and the way forward. J Clin Lipidol 2016; 10:748-756. [DOI: 10.1016/j.jacl.2016.02.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 02/19/2016] [Accepted: 02/20/2016] [Indexed: 10/22/2022]
|
3
|
Mollaki V, Progias P, Drogari E. Familial Hypercholesterolemia in Greek children and their families: genotype-to-phenotype correlations and a reconsideration of LDLR mutation spectrum. Atherosclerosis 2014; 237:798-804. [PMID: 25463123 DOI: 10.1016/j.atherosclerosis.2014.09.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/10/2014] [Accepted: 09/23/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVE Familial Hypercholesterolemia (FH) is a common lipid metabolism disease, resulting in premature atherosclerosis, even from childhood. We aimed to define the genetic basis of FH in children and their families, to refine the spectrum of Low-Density Lipoprotein Receptor gene (LDLR) mutations and identify genotype-to-phenotype correlations in patients of Greek origin. METHODS LDLR was analyzed in 561 patients from 262 families, by whole-gene sequencing. RESULTS Children with identified LDLR mutations showed higher lipid levels compared to non-carriers. Molecular analysis identified a mutation in 53.4% of index cases. Twenty six LDLR mutations were identified, including 19 point mutations, 2 nonsense mutations, 3 splice site mutations and 2 small insertions. Amongst patients with common mutations, carriers of c.1646G > A and c.1285G > A showed higher lipid levels, whereas carriers of c.858C > A and c.81C > G showed a milder phenotype. CONCLUSIONS The spectrum of LDLR mutations in Greece is refined and expanded, with more patients analyzed by whole-gene sequencing. Although a quick screening method is feasible for the Greek population, whole-gene sequencing is essential to identify rare variants. Children with border line lipid levels and a family history of hypercholesterolemia should be considered for molecular diagnosis, since carriers of certain mutations show milder phenotypes and may be missed during clinical diagnosis.
Collapse
Affiliation(s)
- Vasiliki Mollaki
- Unit of Metabolic Diseases, Choremio Research Laboratory, 1st Department of Paediatrics, University of Athens Medical School, "Aghia Sophia" Children's Hospital, Greece.
| | - Pavlos Progias
- Unit of Metabolic Diseases, Choremio Research Laboratory, 1st Department of Paediatrics, University of Athens Medical School, "Aghia Sophia" Children's Hospital, Greece
| | - Euridiki Drogari
- Unit of Metabolic Diseases, Choremio Research Laboratory, 1st Department of Paediatrics, University of Athens Medical School, "Aghia Sophia" Children's Hospital, Greece
| |
Collapse
|
4
|
Mollaki V, Progias P, Drogari E. NovelLDLRVariants in Patients with Familial Hypercholesterolemia:In SilicoAnalysis as a Tool to Predict Pathogenic Variants in Children and Their Families. Ann Hum Genet 2013; 77:426-34. [DOI: 10.1111/ahg.12032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 05/13/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Vasiliki Mollaki
- 1st Department of Pediatrics, Laboratory of Metabolic Diseases, Choremio Research Laboratory; University of Athens Medical School, “Aghia Sophia” Children's Hospital; Athens Greece
| | - Pavlos Progias
- 1st Department of Pediatrics, Laboratory of Metabolic Diseases, Choremio Research Laboratory; University of Athens Medical School, “Aghia Sophia” Children's Hospital; Athens Greece
| | - Euridiki Drogari
- 1st Department of Pediatrics, Laboratory of Metabolic Diseases, Choremio Research Laboratory; University of Athens Medical School, “Aghia Sophia” Children's Hospital; Athens Greece
| |
Collapse
|
5
|
Ahmed W, Whittall R, Riaz M, Ajmal M, Sadeque A, Ayub H, Qamar R, Humphries SE. The genetic spectrum of familial hypercholesterolemia in Pakistan. Clin Chim Acta 2013; 421:219-25. [PMID: 23535506 PMCID: PMC3701840 DOI: 10.1016/j.cca.2013.03.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 03/13/2013] [Indexed: 12/28/2022]
Abstract
Background Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by mutations in the genes coding for the low density lipoprotein receptor (LDLR), proprotein convertase subtilisin/kexin type-9 (PCSK9) or apo-lipoprotein B-100 (APOB). The aim of the present work was to determine the genetic basis of dyslipidemia in 11 unrelated Pakistani families. Methods High resolution melting (HRM), sequencing and restriction fragment length polymorphism (RFLP). Results Probands were screened for the promoter and all coding regions, including intron/exon boundaries, of LDLR and PCSK9 and part of exon 26 of APOB including p.(R3527Q). Two families were identified with previously unreported LDLR mutations (c.1019_1020delinsTG, p.(C340L) and c.1634G>A, p.(G545E)). Both probands had tendon xanthomas or xanthelasma and/or a history of cardiovascular disease. Co-segregation with hypercholesterolemia was demonstrated in both families. In silico studies predicted these variations to be damaging. In two families, novel PCSK9 variations were identified (exon2; c.314G > A, p.(R105Q) and exon3; c.464C>T, p.(P155L)). In silico studies suggested both were likely to be damaging, and family members carrying the p.(105Q) allele had lower total cholesterol levels, suggesting this is a loss-of-function mutation. For c.464C>T p.(P155L) the small number of relatives available precluded any strong inference. Conclusion This report brings to seven the number of different LDLR mutations reported in FH patients from Pakistan and, as expected in this heterogeneous population, no common LDLR mutation has been identified. We examined the LDLR/PCSK9 genes in patients with FH from Pakistan. Two novel LDLR mutations both showed co-segregation with hypercholesterolemia. Two novel PCSK9 variations were found one of which was a loss of function mutation. This brings to 7 the number of molecular causes of FH in patients from Pakistan.
Collapse
Affiliation(s)
- Waqas Ahmed
- COMSATS Institute of Information Technology, Islamabad, Pakistan
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Pećin I, Whittall R, Futema M, Sertić J, Reiner Ž, Leigh SEA, Humphries SE. Mutation detection in Croatian patients with Familial Hypercholesterolemia. Ann Hum Genet 2012; 77:22-30. [DOI: 10.1111/j.1469-1809.2012.00735.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 08/25/2012] [Indexed: 02/03/2023]
Affiliation(s)
- Ivan Pećin
- Department of Internal Medicine; University Hospital Center Zagreb; Croatia
| | - Ros Whittall
- Centre for Cardiovascular Genetics; British Heart Foundation Laboratories, The Rayne Building; Royal Free and University College London Medical School; London; WC1E 6JJ; UK
| | - Marta Futema
- Centre for Cardiovascular Genetics; British Heart Foundation Laboratories, The Rayne Building; Royal Free and University College London Medical School; London; WC1E 6JJ; UK
| | - Jadranka Sertić
- Center for Clinical and Laboratory Diagnostics; University Hospital Center Zagreb; Croatia
| | - Željko Reiner
- Department of Internal Medicine; University Hospital Center Zagreb; Croatia
| | - Sarah E. A. Leigh
- Centre for Cardiovascular Genetics; British Heart Foundation Laboratories, The Rayne Building; Royal Free and University College London Medical School; London; WC1E 6JJ; UK
| | - Steve E. Humphries
- Centre for Cardiovascular Genetics; British Heart Foundation Laboratories, The Rayne Building; Royal Free and University College London Medical School; London; WC1E 6JJ; UK
| |
Collapse
|
7
|
Chiou KR, Charng MJ. Common mutations of familial hypercholesterolemia patients in Taiwan: Characteristics and implications of migrations from southeast China. Gene 2012; 498:100-6. [DOI: 10.1016/j.gene.2012.01.092] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2011] [Accepted: 01/29/2012] [Indexed: 10/14/2022]
|
8
|
Diakou M, Miltiadous G, Xenophontos SL, Manoli P, Cariolou MA, Elisaf M. Spectrum of LDLR gene mutations, including a novel mutation causing familial hypercholesterolaemia, in North-western Greece. Eur J Intern Med 2011; 22:e55-9. [PMID: 21925044 DOI: 10.1016/j.ejim.2011.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 11/30/2010] [Accepted: 01/10/2011] [Indexed: 11/23/2022]
Abstract
BACKGROUND Familial Hypercholesterolaemia (FH) is a clinical syndrome characterised by elevated serum low-density lipoprotein (LDL) cholesterol, by tendon xanthomata and clinical manifestations of ischaemic heart disease in early life. Typically, it results from mutations in the low-density lipoprotein receptor (LDLR) gene. Furthermore, there are 3 additional genetic disorders that cause clinical syndromes that mimic FH. These are: 1) familial ligand-defective apolipoprotein (apo)-B (FLDH), 2) familial hypercholesterolaemia type 3 (FH3) and 3) autosomal recessive hypercholesterolaemia (ARH). The aim of this study was to elaborate the impact of the above genetic disorders in Greek patients with a clinical diagnosis of FH. METHODS In this study, we assessed the contribution of the LDLR, Apo B, ARH and PCSK9 genes in the expression of FH in North-western Greece. Two hundred and fifty-four (254) probands with a clinical diagnosis of FH were included in the study. RESULTS One hundred and sixty-nine (169) patients had one of the following LDLR gene mutations: 81T>G, 1775G>A, 517T>C, 858C>A, 1352T>C, 1285G>A, 761A>C, 1195G>A, 1646G>A and a deletion mutation g.387-410del24 in exon 4. We sequenced the Apo B, ARH and PCSK9 genes in 40, randomly selected patients, from the 85 patients with no identified LDLR gene defects. In these 40, randomly selected patients, with the exception of benign single nucleotide polymorphisms, no functional mutations were identified for all the above mentioned sequenced genes. CONCLUSION Our results reveal substantial genetic heterogeneity for FH in North-western Greece with at least ten LDLR gene mutations present in the study population. One of these mutations although quite rare is reported here for the first time in the scientific literature. The detection of these mutations is important as they may be used to design multiplex detection assays for large scale population screening programmes to facilitate primary and secondary prevention of cardiovascular disease in the region. Finally, ARH, Apo B and PCSK9 gene defects were excluded from causing FH in a subgroup of the study population indicating that other yet unrecognized genes may be involved in causing the clinical feature of FH, and/or that large scale deletions/duplications evaded the applied mutation detection techniques of this study.
Collapse
Affiliation(s)
- Maria Diakou
- Department of Internal medicine, Medical School, University of Ioannina, Ioannina, Greece
| | | | | | | | | | | |
Collapse
|
9
|
Diakou M, Miltiadous G, Xenophontos S, Cariolou M, Heta N, Korita I, Bulo A, Refatllari E, Bairaktari E, Elisaf M. Characterization of low density lipoprotein receptor (LDLR) gene mutations in Albania. Arch Med Sci 2010; 6:198-200. [PMID: 22371747 PMCID: PMC3281340 DOI: 10.5114/aoms.2010.13894] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 08/02/2009] [Accepted: 08/11/2009] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION Familial hypercholesterolaemia (FH) is a clinical syndrome characterised by elevated serum total cholesterol (TCHOL) levels due to an increase in low-density lipoprotein (LDL) cholesterol, by tendon xanthomata and clinical manifestations of ischaemic heart disease in early life. Typically, it results from mutations in the low-density lipoprotein receptor (LDLR) gene. So far, more than 800 mutations have been reported for the LDLR gene and account for FH. The nature of LDLR gene mutations varies among different ethnicities. Until now no mutations of LDLR have been reported in the Albanian population. MATERIAL AND METHODS We assessed the contribution of the LDLR gene mutations as causes of FH in an Albanian population. Fifty probands with a clinical diagnosis of FH were included. We analysed all the exons and the promoter of the LDLR gene by using restriction isotyping or direct sequencing. RESULTS Twenty-one patients were heterozygous for the 1646G>A mutation (FH Genoa) in exon 11 and 9 patients were heterozygous for the 81T>C mutation in exon 2 of the LDLR gene. CONCLUSIONS This report describes two LDLR gene mutations accounting for FH in Albania (1646G>A, 81T>C).
Collapse
Affiliation(s)
- Maria Diakou
- Department of Internal Medicine, Medical School, University of Ioannina, Ioannina, Greece
- Molecular Genetics Dept. B-DNA Identification Laboratory, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - George Miltiadous
- Department of Internal Medicine, Medical School, University of Ioannina, Ioannina, Greece
- Molecular Genetics Dept. B-DNA Identification Laboratory, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Stavroula Xenophontos
- Molecular Genetics Dept. B-DNA Identification Laboratory, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Marios Cariolou
- Molecular Genetics Dept. B-DNA Identification Laboratory, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Nevila Heta
- University Hospital Centre “Mother Teresa”, School of Medicine, Rr Kavajes, Tirana, Albania
| | - Irena Korita
- University Hospital Centre “Mother Teresa”, School of Medicine, Rr Kavajes, Tirana, Albania
| | - Anyla Bulo
- University Hospital Centre “Mother Teresa”, School of Medicine, Rr Kavajes, Tirana, Albania
| | - Etleva Refatllari
- University Hospital Centre “Mother Teresa”, School of Medicine, Rr Kavajes, Tirana, Albania
| | - Eleni Bairaktari
- University Hospital Centre “Mother Teresa”, School of Medicine, Rr Kavajes, Tirana, Albania
| | - Moses Elisaf
- Department of Internal Medicine, Medical School, University of Ioannina, Ioannina, Greece
| |
Collapse
|
10
|
Whittall RA, Scartezini M, Li K, Hubbart C, Reiner Z, Abraha A, Neil HAW, Dedoussis G, Humphries SE. Development of a high-resolution melting method for mutation detection in familial hypercholesterolaemia patients. Ann Clin Biochem 2009; 47:44-55. [DOI: 10.1258/acb.2009.009076] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Aims Current screening methods, such as single strand conformational polymorphism (SSCP) and denaturing high performance liquid chromatography (dHPLC) that are used for detecting mutations in familial hypercholesterolaemia (FH) subjects are time consuming, costly and only 80–90% sensitive. Here we have tested high-resolution melt (HRM) analysis for mutation detection using the Rotor-Gene6000 realtime rotary analyser. Methods and subjects Polymerase chain reaction and melt conditions (HRM) for 23 fragments of the LDL-receptor gene, a region of exon 26 in the APOB gene (including p.R3527Q) and exon 7 of the PCSK9 gene (including p.D374Y) were optimized. Two double stranded DNA saturating dyes, LC-Green and Syto9, were compared for sensitivity. Eighty-two samples with known mutations were used as positive controls. Twenty-eight Greek FH heterozygous patients and two homozygous patients from the UK and Croatia were screened. Results HRM was able to identify all the positive control mutations tested, with similar results with either dye. Eight different variations were found in 17 of the 28 Greek FH patients for an overall detection rate of 61%: c.41delT (1), p.W165X (1), p.C173R (3), p.S286R (2), p.V429M (4), p.G549D (4), p.V613I (1), and a previously unreported mutation p.F694V (1) which is predicted to be FH-causing by functional algorithms. Mutations were found in both the homozygous patients; p.Q92X (Croatia) and p.Y489C (UK); both patients were homozygous for their respective mutations. Conclusions HRM is a sensitive, robust technique that could significantly reduce the time and cost of screening for mutations in a clinical setting.
Collapse
Affiliation(s)
- R A Whittall
- Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Royal Free and University College London Medical School, London WC1E 6JJ, UK
| | - M Scartezini
- Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Royal Free and University College London Medical School, London WC1E 6JJ, UK
- Department of Medical Pathology, Federal University of Paraná, Curitiba–Paraná, 80210–170, Brazil
| | - KaWah Li
- Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Royal Free and University College London Medical School, London WC1E 6JJ, UK
| | - C Hubbart
- Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Royal Free and University College London Medical School, London WC1E 6JJ, UK
| | - Z Reiner
- Department of Internal Medicine, University Hospital Center Zagreb, Zagreb 1000, Croatia
| | - A Abraha
- Department of Clinical Biochemistry, Stoke Mandeville Hospital, Aylesbury HP21 8AL, UK
| | - H A W Neil
- Division Public Health & Primary Health Care, University of Oxford, Oxford OX3 7LF, UK
| | - G Dedoussis
- Department of Dietetics-Nutrition, Harokopio University, Athens 17671, Greece
| | - S E Humphries
- Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Royal Free and University College London Medical School, London WC1E 6JJ, UK
| |
Collapse
|
11
|
Biros E, Karan M, Golledge J. Genetic variation and atherosclerosis. Curr Genomics 2008; 9:29-42. [PMID: 19424482 PMCID: PMC2674308 DOI: 10.2174/138920208783884856] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 02/22/2008] [Accepted: 02/22/2008] [Indexed: 01/06/2023] Open
Abstract
A family history of atherosclerosis is independently associated with an increased incidence of cardiovascular events. The genetic factors underlying the importance of inheritance in atherosclerosis are starting to be understood. Genetic variation, such as mutations or common polymorphisms has been shown to be involved in modulation of a range of risk factors, such as plasma lipoprotein levels, inflammation and vascular calcification. This review presents examples of present studies of the role of genetic polymorphism in atherosclerosis.
Collapse
Affiliation(s)
| | | | - Jonathan Golledge
- Vascular Biology Unit, School of Medicine, James Cook University, Townsville, QLD 4811, Australia
| |
Collapse
|
12
|
Glynou K, Laios E, Drogari E, Tsaoussis V. Development of a universal chemiluminometric genotyping method for high-throughput detection of 7 LDLR gene mutations in Greek population. Clin Biochem 2008; 41:335-42. [PMID: 18206115 DOI: 10.1016/j.clinbiochem.2007.12.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 12/12/2007] [Accepted: 12/12/2007] [Indexed: 02/03/2023]
Abstract
OBJECTIVES Familial hypercholesterolemia (FH) is caused by mutations in the LDL receptor (LDLR) gene. We report the application of a universal method with high allele discrimination properties to the simultaneous genotyping of 7 LDLR mutations in Greeks, in dry-reagent format. DESIGN AND METHODS We genotyped mutations C858A, C939A, G1285A, T1352C, G1646A, G1775A, C/T81G. Unpurified amplicons from a multiplex PCR that produced fragments encompassing all 7 mutations were subjected to probe extension reactions in the presence of fluorescein-modified dCTP, and a microtiter well-based assay of extension products with a peroxidase-antifluorescein conjugate and a chemiluminogenic substrate. We used lyophilized dry reagents and assigned genotypes by the signal ratio of normal-to-mutant-specific probe. RESULTS We standardized the method and optimised all steps for specificity. The method was validated by genotyping blindly 119 (833 genotypings). Results were fully concordant with other methods used as standards. CONCLUSIONS This method is accurate, simple, rapid and robust. The microtiter well format allows genotyping of a large number of samples in parallel for several mutations.
Collapse
|
13
|
Laios E, Drogari E. Analysis of LDLR mutations in familial hypercholesterolemia patients in Greece by use of the NanoChip® Microelectronic Array Technology. Clin Chim Acta 2006; 374:93-9. [PMID: 16828076 DOI: 10.1016/j.cca.2006.05.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 05/26/2006] [Accepted: 05/26/2006] [Indexed: 01/24/2023]
Abstract
BACKGROUND Three mutations in the low density lipoprotein receptor (LDLR) gene account for 49% of familial hypercholesterolemia (FH) cases in Greece. METHODS We used the microelectronic array technology of the NanoChip Molecular Biology Workstation to develop a multiplex method to analyze these single-nucleotide polymorphisms (SNPs). Primer pairs amplified the region encompassing each SNP. The biotinylated PCR amplicon was electronically addressed to streptavidin-coated microarray sites. Allele-specific fluorescently labeled oligonucleotide reporters were designed and used for detection of wild-type and SNP sequences. Genotypes were compared to PCR-restriction fragment length polymorphism (PCR-RFLP). RESULTS We developed three monoplex assays (1 SNP/site) and an optimized multiplex assay (3SNPs/site). We performed 92 Greece II, 100 Genoa, and 98 Afrikaner-2 NanoChip monoplex assays (addressed to duplicate sites and analyzed separately). Of the 580 monoplex genotypings (290 samples), 579 agreed with RFLP. Duplicate sites of one sample were not in agreement with each other. Of the 580 multiplex genotypings, 576 agreed with the monoplex results. Duplicate sites of three samples were not in agreement with each other, indicating requirement for repetition upon which discrepancies were resolved. CONCLUSIONS The multiplex assay detects common LDLR mutations in Greek FH patients and can be extended to accommodate additional mutations.
Collapse
Affiliation(s)
- Eleftheria Laios
- Unit on Metabolic Diseases, Choremio Research Laboratory, University of Athens, 1st Department of Pediatrics, Aghia Sophia Children's Hospital, Athens 11527, Greece.
| | | |
Collapse
|
14
|
Dedoussis GVZ, Skoumas J, Pitsavos C, Choumerianou DM, Genschel J, Schmidt H, Stefanadis C. FH clinical phenotype in Greek patients with LDL-R defective vs. negative mutations. Eur J Clin Invest 2004; 34:402-9. [PMID: 15200491 DOI: 10.1111/j.1365-2362.2004.01351.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Familial hypercholesterolaemia (FH) is caused by mutations in the low-density lipoprotein receptor gene and the gene encoding apolipoprotein B-100, affecting one in 500 individuals. METHODS One hundred and eighty-three Greek FH patients were screened for mutations on the LDLR and ApoB genes. RESULTS We identified mutations in 67 probands and 11 relatives. Sixteen mutations located in eight different exons and the promoter of the LDLR were discovered. Among them 10 were missense mutations (C6W, S265R, A370T, Q363P, D365E, V408M, A410T, A517T, G528D, G571E), two were nonsense mutations (Q363X and C660X), three were splice defects (2140 + 5G-->A and 2140 + 9C-->T, 1706 - 10G-->A), and one was a nucleotide substitution (- 45delT) on the promoter. None of the subjects carried any apoB mutation. The detection rate of mutations in this study was 43%. From the above mutations, A410T, A519T and the splice site defects 2140 + 9C-->T were detected for the first time in the Greek population. Among them V408M, G528D, C6W and S265R account for 73% of heterozygous FH probands. V408M mutation is more common in Central West, while C6W is more common in Central East. Separating the patients into two groups (receptor defective and receptor negative) we found that the receptor negative group had higher levels of total cholesterol, low-density lipoprotein cholesterol and higher prevalence of tendon xanthomas compared with the receptor-defective group. DISCUSSION The homogenous molecular basis of familial hypercholesterolaemia in Greece facilitates the application of a DNA diagnostic strategy based on the origin of the patient. The early mutation analysis would add valuable information on the severity of the disease.
Collapse
Affiliation(s)
- G V Z Dedoussis
- Laboratory of Molecular Biology, Department of Science of Dietetics-Nutrition, Harokopio University of Athens, Athens, Greece.
| | | | | | | | | | | | | |
Collapse
|
15
|
Abstract
Familial hypercholesterolemia (FH) is a clinical definition for a remarkable increase of cholesterol serum concentration, presence of xanthomas, and an autosomal dominant trait of either increased serum cholesterol or premature coronary artery disease (CAD). The identification of the low-density lipoprotein (LDL)-receptor (LDLR) as the underlying cause and its genetic characterization in FH patients revealed more insights in the trafficking of LDL, which primarily transports cholesterol to hepatic and peripheral cells. Mutations within LDLR result in hypercholesterolemia and, subsequently, cholesterol deposition in humans to a variable degree. This confirms the pathogenetic role of LDLR and also highlights the existence of additional factors in determining the phenotype. Autosomal dominant FH is caused by LDLR deficiency and defective apolipoprotein B-100 (APOB), respectively. Heterozygosity of the LDLR is relatively common (1:500). Clinical diagnosis is highly important and genetic diagnosis may be helpful, since treatment is usually effective for this otherwise fatal disease. Very recently, mutations in PCSK9 have been also shown to cause autosomal dominant hypercholesterolemia. For autosomal recessive hypercholesterolemia, mutations within the so-called ARH gene encoding a cellular adaptor protein required for LDL transport have been identified. These insights emphasize the crucial importance of LDL metabolism intra- and extracellularly in determining LDL-cholesterol serum concentration. Herein, we focus on the published European LDLR mutation data that reflect its heterogeneity and phenotypic penetrance.
Collapse
Affiliation(s)
- George V Z Dedoussis
- Department of Science Dietetics-Nutrition, Harokopio University of Athens, Athens, Greece
| | | | | |
Collapse
|
16
|
Bertolini S, Cantafora A, Averna M, Cortese C, Motti C, Martini S, Pes G, Postiglione A, Stefanutti C, Blotta I, Pisciotta L, Rolleri M, Langheim S, Ghisellini M, Rabbone I, Calandra S. Clinical expression of familial hypercholesterolemia in clusters of mutations of the LDL receptor gene that cause a receptor-defective or receptor-negative phenotype. Arterioscler Thromb Vasc Biol 2000; 20:E41-52. [PMID: 10978268 DOI: 10.1161/01.atv.20.9.e41] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Seventy-one mutations of the low density lipoprotein (LDL) receptor gene were identified in 282 unrelated Italian familial hypercholesterolemia (FH) heterozygotes. By extending genotype analysis to families of the index cases, we identified 12 mutation clusters and localized them in specific areas of Italy. To evaluate the impact of these mutations on the clinical expression of FH, the clusters were separated into 2 groups: receptor-defective and receptor-negative, according to the LDL receptor defect caused by each mutation. These 2 groups were comparable in terms of the patients' age, sex distribution, body mass index, arterial hypertension, and smoking status. In receptor-negative subjects, LDL cholesterol was higher (+18%) and high density lipoprotein cholesterol lower (-5%) than the values found in receptor-defective subjects. The prevalence of tendon xanthomas and coronary artery disease (CAD) was 2-fold higher in receptor-negative subjects. In patients >30 years of age in both groups, the presence of CAD was related to age, arterial hypertension, previous smoking, and LDL cholesterol level. Independent contributors to CAD in the receptor-defective subjects were male sex, arterial hypertension, and LDL cholesterol level; in the receptor-negative subjects, the first 2 variables were strong predictors of CAD, whereas the LDL cholesterol level had a lower impact than in receptor-defective subjects. Overall, in receptor-negative subjects, the risk of CAD was 2.6-fold that of receptor-defective subjects. Wide interindividual variability in LDL cholesterol levels was found in each cluster. Apolipoprotein E genotype analysis showed a lowering effect of the epsilon2 allele and a raising effect of the epsilon4 allele on the LDL cholesterol level in both groups; however, the apolipoprotein E genotype accounted for only 4% of the variation in LDL cholesterol. Haplotype analysis showed that all families of the major clusters shared the same intragenic haplotype cosegregating with the mutation, thus suggesting the presence of common ancestors.
Collapse
Affiliation(s)
- S Bertolini
- Department of Internal Medicine, University of Genoa, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Jensen HK, Jensen LG, Meinertz H, Hansen PS, Gregersen N, Faergeman O. Spectrum of LDL receptor gene mutations in Denmark: implications for molecular diagnostic strategy in heterozygous familial hypercholesterolemia. Atherosclerosis 1999; 146:337-44. [PMID: 10532689 DOI: 10.1016/s0021-9150(99)00158-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Heterozygous familial hypercholesterolemia (FH) is one of the most common potentially fatal single-gene diseases leading to premature coronary artery disease, but the majority of heterozygous FH patients have not been diagnosed. FH is due to mutations in the gene coding for the low-density lipoprotein (LDL) receptor, and molecular genetic diagnosis may facilitate identification of more FH subjects. The Danish spectrum of 29 different mutations, five of which account for almost half of heterozygous FH, is intermediate between that of countries such as South Africa, where three mutations cause 95% of heterozygous FH in the Afrikaners, and Germany or England, where there are many more mutations. In clinical practice, a strategy for the genetic diagnosis of heterozygous FH, tailored to the mutational spectrum of patients likely to be seen at the particular hospital/region of the country, will be more efficient than screening of the whole LDL receptor gene by techniques such as single-strand conformation polymorphism (SSCP) analysis in every heterozygous FH candidate. In Aarhus, Denmark, we have chosen to examine all heterozygous FH candidates for the five most common LDL receptor gene mutations (W23X, W66G, W556S, 313 + 1G --> A, 1846 - 1G --> A) and the apoB-3500 mutation by rapid restriction fragment analysis. Negative samples are examined for other mutations by SSCP analysis followed by DNA sequencing of the exon indicated by SSCP to contain a mutation. If no point mutation or small insertion/deletion is detected, Southern blot or Long PCR analysis is performed to look for the presence of large gene rearrangements. In conclusion, our data suggest that an efficient molecular diagnostic strategy depends on the composition of common and rare mutations in a population.
Collapse
Affiliation(s)
- H K Jensen
- Department of Medicine and Cardiology, Aarhus Amtssygehus University Hospital, Aarhus C, Denmark.
| | | | | | | | | | | |
Collapse
|
18
|
Bourbon M, Fowler AM, Sun XM, Soutar AK. Inheritance of two different alleles of the low-density lipoprotein (LDL)-receptor gene carrying the recurrent Pro664Leu mutation in a patient with homozygous familial hypercholesterolaemia. Clin Genet 1999; 56:225-31. [PMID: 10563483 DOI: 10.1034/j.1399-0004.1999.560308.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Familial hypercholesterolaemia (FH) is caused by mutations in the low-density lipoprotein (LDL)-receptor gene that result in impaired clearance of plasma LDL and increased risk of coronary heart disease. Numerous different mutations have been found in FH patients worldwide, the majority of which are infrequent in out-bred populations and account for 2% or less of patients with the disorder in large cohorts. Thus, it was surprising to find that two homozygous FH patients referred to a single hospital in the UK were both apparently homozygous for the Pro664Leu mutation. One, an Asian patient, was a true homozygote. The other, of English origin, had inherited two different alleles of the LDL-receptor gene with the same mutation from unrelated parents, as inferred from the haplotype of polymorphic markers. A third, clinically homozygous FH patient, despite being the offspring of first cousins, had inherited one 'Asian' Pro664Leu allele, but an allele with a 1-bp deletion in exon 5 from the other parent. The Pro664Leu mutation in the LDL-receptor gene has now been described in heterozygous patients of very different ethnic origin and is associated with different haplotypes, suggesting that the same base change at a CpG may have recurred as many as six times.
Collapse
Affiliation(s)
- M Bourbon
- Lipoprotein Group, MRC Clinical Sciences Centre, Hammersmith Hospital, London, UK
| | | | | | | |
Collapse
|
19
|
Page GP, Amos CI. Comparison of linkage-disequilibrium methods for localization of genes influencing quantitative traits in humans. Am J Hum Genet 1999; 64:1194-205. [PMID: 10090905 PMCID: PMC1377844 DOI: 10.1086/302331] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Linkage disequilibrium has been used to help in the identification of genes predisposing to certain qualitative diseases. Although several linkage-disequilibrium tests have been developed for localization of genes influencing quantitative traits, these tests have not been thoroughly compared with one another. In this report we compare, under a variety of conditions, several different linkage-disequilibrium tests for identification of loci affecting quantitative traits. These tests use either single individuals or parent-child trios. When we compared tests with equal samples, we found that the truncated measured allele (TMA) test was the most powerful. The trait allele frequencies, the stringency of sample ascertainment, the number of marker alleles, and the linked genetic variance affected the power, but the presence of polygenes did not. When there were more than two trait alleles at a locus in the population, power to detect disequilibrium was greatly diminished. The presence of unlinked disequilibrium (D'*) increased the false-positive error rates of disequilibrium tests involving single individuals but did not affect the error rates of tests using family trios. The increase in error rates was affected by the stringency of selection, the trait allele frequency, and the linked genetic variance but not by polygenic factors. In an equilibrium population, the TMA test is most powerful, but, when adjusted for the presence of admixture, Allison test 3 becomes the most powerful whenever D'*>.15.
Collapse
Affiliation(s)
- G P Page
- Department of Epidemiology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | | |
Collapse
|