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Futema M, Taylor-Beadling A, Williams M, Humphries SE. Genetic testing for familial hypercholesterolemia-past, present, and future. J Lipid Res 2021; 62:100139. [PMID: 34666015 PMCID: PMC8572866 DOI: 10.1016/j.jlr.2021.100139] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 09/22/2021] [Accepted: 10/02/2021] [Indexed: 01/01/2023] Open
Abstract
In the early 1980s, the Nobel Prize winning cellular and molecular work of Mike Brown and Joe Goldstein led to the identification of the LDL receptor gene as the first gene where mutations cause the familial hypercholesterolemia (FH) phenotype. We now know that autosomal dominant monogenic FH can be caused by pathogenic variants of three additional genes (APOB/PCSK9/APOE) and that the plasma LDL-C concentration and risk of premature coronary heart disease differs according to the specific locus and associated molecular cause. It is now possible to use next-generation sequencing to sequence all exons of all four genes, processing 96 patient samples in one sequencing run, increasing the speed of test results, and reducing costs. This has resulted in the identification of not only many novel FH-causing variants but also some variants of unknown significance, which require further evidence to classify as pathogenic or benign. The identification of the FH-causing variant in an index case can be used as an unambiguous and rapid test for other family members. An FH-causing variant can be found in 20-40% of patients with the FH phenotype, and we now appreciate that in the majority of patients without a monogenic cause, a polygenic etiology for their phenotype is highly likely. Compared with those with a monogenic cause, these patients have significantly lower risk of future coronary heart disease. The use of these molecular genetic diagnostic methods in the characterization of FH is a prime example of the utility of precision or personalized medicine.
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Affiliation(s)
- Marta Futema
- Centre for Heart Muscle Disease, Institute of Cardiovascular Science, University College London, London, United Kingdom; Molecular and Clinical Sciences Research Institute, St George's University of London, London, United Kingdom
| | - Alison Taylor-Beadling
- Regional Molecular Genetics Laboratory, Great Ormond Street Hospital for Children, London, United Kingdom
| | | | - Steve E Humphries
- Institute of Cardiovascular Science, University College London, London, United Kingdom.
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Chiou KR, Charng MJ. Detection of common sequence variations of familial hypercholesterolemia in Taiwan using DNA mass spectrometry. J Clin Lipidol 2017; 11:386-393.e6. [DOI: 10.1016/j.jacl.2016.12.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/21/2016] [Accepted: 12/30/2016] [Indexed: 01/18/2023]
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Jeenduang N, Porntadavity S, von Nickisch-Rosenegk M, Bier FF, Promptmas C. Two-dye based arrayed primer extension for simultaneous multigene detection in lipid metabolism. Clin Chim Acta 2015; 442:36-43. [PMID: 25591965 DOI: 10.1016/j.cca.2015.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 01/08/2015] [Accepted: 01/08/2015] [Indexed: 01/24/2023]
Abstract
BACKGROUND Cardiovascular disease (CVD) is one of the major causes of death worldwide. Numerous genetic risk factors in lipid metabolism, including mutations of LDLR, APOB, and PCSK9, as well as polymorphisms of CETP and APOE, have been found to associate with CVD. METHODS In this study, a two-dye based arrayed primer extension (APEX) microarray assay for simultaneous multigene (LDLR, APOB, PCSK9, CETP, and APOE) detection was developed. The DNA templates, originating from 1 DNA sample of known genotype and 7 blind DNA samples, were amplified by uniplex PCR. RESULTS Optimized conditions for the APEX reaction were determined to include a hybridization temperature of 55°C and a DNA template size of 50-150bp. The total assay including PCR, purification, fragmentation, APEX reaction, and image analysis could be performed in 6h. In total, 48 genotypes were identified among 8 individual DNA samples by APEX analysis. CONCLUSIONS The data suggest that this APEX microarray offers a robust, fast, and versatile option for screening these genotypes in hypercholesterolemia patients.
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Affiliation(s)
- Nutjaree Jeenduang
- School of Allied Health Science and Public Health, Walailak University, Nakhon Si Thammarat 80161, Thailand; Department of Nanobiotechnology and Nanomedicine, Fraunhofer Institute for Biomedical Engineering (IBMT), Potsdam-Golm 14476, Germany
| | - Sureerut Porntadavity
- Department of Clinical Chemistry, Faculty of Medical Technology, Mahidol University, Nakhon Pathom 73170, Thailand
| | - Markus von Nickisch-Rosenegk
- Department of Nanobiotechnology and Nanomedicine, Fraunhofer Institute for Biomedical Engineering (IBMT), Potsdam-Golm 14476, Germany
| | - Frank F Bier
- Department of Nanobiotechnology and Nanomedicine, Fraunhofer Institute for Biomedical Engineering (IBMT), Potsdam-Golm 14476, Germany
| | - Chamras Promptmas
- Department of Biomedical Engineering, Faculty of Engineering, Mahidol University, Nakhon Pathom 73170, Thailand.
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Faiz F, Nguyen LT, van Bockxmeer FM, Hooper AJ. Genetic screening to improve the diagnosis of familial hypercholesterolemia. ACTA ACUST UNITED AC 2014. [DOI: 10.2217/clp.14.32] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Khamis A, Palmen J, Lench N, Taylor A, Badmus E, Leigh S, Humphries SE. Functional analysis of four LDLR 5'UTR and promoter variants in patients with familial hypercholesterolaemia. Eur J Hum Genet 2014; 23:790-5. [PMID: 25248394 PMCID: PMC4277481 DOI: 10.1038/ejhg.2014.199] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 06/26/2014] [Accepted: 07/09/2014] [Indexed: 11/09/2022] Open
Abstract
Familial hypercholesterolaemia (FH) is an autosomal dominant inherited disease characterised by increased low-density lipoprotein cholesterol (LDL-C) levels. The functionality of four novel variants within the LDLR 5'UTR and promoter located at c.-13A>G, c.-101T>C, c.-121T>C and c.-215A>G was investigated using in silico and in vitro assays, and a systemic bioinformatics analysis of all 36 reported promoter variants are presented. Bioinformatic tools predicted that all four variants occurred in sites likely to bind transcription factors and that binding was altered by the variant allele. Luciferase assay was performed for all the variants. Compared with wild type, the c.-101T>C and c.-121T>C variants showed significantly lower mean (±SD) luciferase activity (64 ± 8 and 72 ± 8%, all P<0.001), suggesting that these variants are causal of the FH phenotype. No significant effect on gene expression was seen for the c.-13A>G or c.-215A>G variants (96 ± 15 and 100 ± 12%), suggesting these variants are not FH causing. Similar results were seen for the c.-101T>C and c.-121T>C variants in lipid-depleted serum. However, a significant reduction in luciferase activity was seen in the c.-215A>G variant in lipid-depleted serum. Electrophoretic-mobility shift assays identified allele-specific binding of liver (hepatoma) nuclear proteins to c.-121T>C and suggestive differential binding to c.-101T>C but no binding to c.-215A>G. These data highlight the importance of in vitro testing of reported LDLR promoter variants to establish their role in FH. The functional assays performed suggest that the c.-101T>C and c.-121T>C variants are pathogenic, whereas c.-13A>G variant is benign, and the status of c.-215A>G remains unclear.
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Affiliation(s)
- Amna Khamis
- Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Institute Cardiovascular Science, University College London Medicine School, London, UK
| | - Jutta Palmen
- Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Institute Cardiovascular Science, University College London Medicine School, London, UK
| | - Nick Lench
- NE Thames Regional Genetics Service, Great Ormond Street Hospital, London, UK
| | - Alison Taylor
- NE Thames Regional Genetics Service, Great Ormond Street Hospital, London, UK
| | - Ebele Badmus
- Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Institute Cardiovascular Science, University College London Medicine School, London, UK
| | - Sarah Leigh
- Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Institute Cardiovascular Science, University College London Medicine School, London, UK
| | - Steve E Humphries
- Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Institute Cardiovascular Science, University College London Medicine School, London, UK
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Fahed AC, Bitar FF, Khalaf RI, Moubarak EM, Azar ST, Nemer GM. The Lebanese allele at the LDLR in normocholesterolemic people merits reconsideration of genotype phenotype correlations in familial hypercholesterolemia. Endocrine 2012; 42:445-8. [PMID: 22487947 DOI: 10.1007/s12020-012-9669-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Accepted: 03/31/2012] [Indexed: 11/26/2022]
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Abstract
Familial hypercholesterolaemia (FH) is an autosomal dominant disorder characterised by increased plasma concentrations of low density lipoprotein (LDL) cholesterol leading to atherosclerosis and premature coronary heart disease (CHD) and death. The clinical diagnosis of FH is based on a personal and family history, physical examination findings and LDL-cholesterol concentrations. FH is primarily caused by mutations in the LDL-receptor gene (LDLR), and less frequently by mutations in genes for APOB and the more recently identified PCSK9. Lifestyle modification and pharmacotherapy can delay or prevent the onset of CHD in FH. It is estimated that only 20% of cases have been diagnosed in Australia and that the majority are inadequately treated. Screening options for FH include population screening (of children or adults), targeted screening of patients with premature CHD and their relatives, or opportunistic screening such as flagging laboratory lipid reports. Cascade screening, a form of targeted screening, is an ethically acceptable, cost-effective strategy for the identification of FH. However, for screening to be successful, medical practitioners need to be aware of the signs and diagnosis of FH and the benefits of early treatment.
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Fahed AC, Safa RM, Haddad FF, Bitar FF, Andary RR, Arabi MT, Azar ST, Nemer G. Homozygous familial hypercholesterolemia in Lebanon: a genotype/phenotype correlation. Mol Genet Metab 2011; 102:181-8. [PMID: 21145767 DOI: 10.1016/j.ymgme.2010.11.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 11/05/2010] [Indexed: 11/28/2022]
Abstract
Familial hypercholesterolemia (FH) is an inherited disease characterized by the deposition of LDL in tissues causing premature atherosclerosis. Many genes are implicated in FH resulting in a large variability in the phenotype. DNA sequencing of the LDLR gene was done for forty patients clinically diagnosed with homozygous FH and forty family members variably affected. Patients underwent noninvasive heart and vascular studies. Statistical and pedigree analyses were used to correlate the different genotypes with the phenotypes. The prevalence of homozygosity at the Lebanese allele (2043C>A) is 45%. However, 27.5% of the patients have no mutations at all in the LDLR gene, and 27.5% are either heterozygous for the 2043C>A mutation, heterozygous for a mutation in another exon of the LDLR gene, or combined heterozygous for two different mutations. We confirm previous reports on the higher prevalence of FH in Lebanon. Our results do, however contradict previous reports on an assumed higher prevalence among the Christian Lebanese. Mutations in the LDLR especially combined heterozygosity can cause a severe phenotype similar to the homozygous mutation in the Lebanese allele. This information is particularly important in targeting the more prevalent heterozygotes in the general population with early diagnosis and intervention.
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Affiliation(s)
- Akl C Fahed
- Department of Biochemistry, American University of Beirut, Bliss Street, Beirut, Lebanon
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Taylor A, Wang D, Patel K, Whittall R, Wood G, Farrer M, Neely RDG, Fairgrieve S, Nair D, Barbir M, Jones JL, Egan S, Everdale R, Lolin Y, Hughes E, Cooper JA, Hadfield SG, Norbury G, Humphries SE. Mutation detection rate and spectrum in familial hypercholesterolaemia patients in the UK pilot cascade project. Clin Genet 2010; 77:572-80. [PMID: 20236128 DOI: 10.1111/j.1399-0004.2009.01356.x] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Cascade testing using DNA-mutation information is now recommended in the UK for patients with familial hypercholesterolaemia (FH). We compared the detection rate and mutation spectrum in FH patients with a clinical diagnosis of definite (DFH) and possible (PFH) FH. Six hundred and thirty-five probands from six UK centres were tested for 18 low-density lipoprotein receptor gene (LDLR) mutations, APOB p.Arg3527Gln and PCSK9 p.Asp374Tyr using a commercial amplification refractory mutation system (ARMS) kit. Samples with no mutation detected were screened in all exons by single strand conformation polymorphism analysis (SSCP)/denaturing high performance liquid chromatography electrophoresis (dHPLC)/direct-sequencing, followed by multiplex ligation-dependent probe amplification (MLPA) to detect deletions and duplications in LDLR.The detection rate was significantly higher in the 190 DFH patients compared to the 394 PFH patients (56.3% and 28.4%, p > 0.00001). Fifty-one patients had inadequate information to determine PFH/DFH status, and in this group the detection rate was similar to the PFH group (25.5%, p = 0.63 vs PFH). Overall, 232 patients had detected mutations (107 different; 6.9% not previously reported). The ARMS kit detected 100 (44%) and the MLPA kit 11 (4.7%). Twenty-eight (12%) of the patients had the APOB p.Arg3527Gln and four (1.7%) had the PCSK9 p.Asp374Tyr mutation. Of the 296 relatives tested from 100 families, a mutation was identified in 56.1%. In 31 patients of Indian/Asian origin 10 mutations (two previously unreported) were identified. The utility of the ARMS kit was confirmed, but sequencing is still required in a comprehensive diagnostic service for FH. Even in subjects with a low clinical suspicion of FH, and in those of Indian origin, mutation testing has an acceptable detection rate.
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Affiliation(s)
- A Taylor
- Great Ormond Street Hospital for Children, London, UK
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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.
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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
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Taylor A, Martin B, Wang D, Patel K, Humphries SE, Norbury G. Multiplex ligation-dependent probe amplification analysis to screen for deletions and duplications of the LDLR gene in patients with familial hypercholesterolaemia. Clin Genet 2009; 76:69-75. [PMID: 19538517 DOI: 10.1111/j.1399-0004.2009.01168.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The most common genetic defect in patients with autosomal dominant hypercholesterolaemia is a mutation of the low-density lipoprotein receptor (LDLR) gene. An estimate of the frequency of major rearrangements has been limited by the availability of an effective analytical method and testing of large cohorts. We present data from a cohort of 611 patients referred with suspected heterozygous familial hypercholesterolaemia (FH) from five UK lipid clinics, who were initially screened for point mutations in LDLR and the common APOB and PCSK9 mutations. The 377 cases in whom no mutation was found were then screened for large rearrangements by multiplex ligation-dependent probe amplification (MLPA) analysis. A rearrangement was identified in 19 patients. This represents 7.5% of the total detected mutations of the cohort. Of these, the majority of mutations (12/19) were deletions of more than one exon, two were duplications of more than one exon and five were single exon deletions that need interpreting with care. Five rearrangements (26%) are previously unreported. We conclude that MLPA analysis is a simple and rapid method for detecting large rearrangements and should be included in diagnostic genetic testing for FH.
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Affiliation(s)
- A Taylor
- Regional Molecular Genetics Laboratory, Great Ormond Street Hospital for Children, London WC1N 3JH, UK
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12
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Laurie AD, George PM. Evaluation of high-resolution melting analysis for screening the LDL receptor gene. Clin Biochem 2009; 42:528-35. [DOI: 10.1016/j.clinbiochem.2008.11.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 10/28/2008] [Accepted: 11/28/2008] [Indexed: 01/08/2023]
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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.
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Camilot M, Teofoli F, Vincenzi M, Federici F, Perlini S, Tatò L. Implementation of a Congenital Hypothyroidism Newborn Screening Procedure with Mutation Detection on Genomic DNA Extracted from Blood Spots: The Experience of the Italian Northeastern Reference Center. ACTA ACUST UNITED AC 2007; 11:387-90. [DOI: 10.1089/gte.2007.0033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Marta Camilot
- Department of Mother and Child, Biology-Genetics, Division of Paediatrics, University of Verona, Verona, Italy
| | - Francesca Teofoli
- Department of Mother and Child, Biology-Genetics, Division of Paediatrics, University of Verona, Verona, Italy
| | - Monica Vincenzi
- Department of Mother and Child, Biology-Genetics, Division of Paediatrics, University of Verona, Verona, Italy
| | - Francesca Federici
- Department of Mother and Child, Biology-Genetics, Division of Paediatrics, University of Verona, Verona, Italy
| | - Silvia Perlini
- Department of Mother and Child, Biology-Genetics, Division of Paediatrics, University of Verona, Verona, Italy
| | - Luciano Tatò
- Department of Mother and Child, Biology-Genetics, Division of Paediatrics, University of Verona, Verona, Italy
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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.
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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.
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Fouchier SW, Kastelein JJP, Defesche JC. Update of the molecular basis of familial hypercholesterolemia in The Netherlands. Hum Mutat 2005; 26:550-6. [PMID: 16250003 DOI: 10.1002/humu.20256] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Autosomal-dominant hypercholesterolemia (ADH) has been identified as a major risk factor for coronary vascular disease (CVD) and is associated with mutations in the low-density lipoprotein receptor (LDLR) and the apolipoprotein B (APOB) gene. Since 1991 DNA samples from clinically diagnosed ADH patients have been routinely analyzed for the presence of LDLR and APOB gene mutations. As of 2001, 1,641 index patients (164 index patients per year) had been identified, while from 2001 onward a more sensitive, high-throughput system was used, resulting in the identification of 1,177 new index patients (average=294 index patients per year). Of these 1,177 index cases, 131 different causative genetic variants in the LDLR gene and six different causative mutations in the APOB gene were new for the Dutch population. Of these 131 mutations, 83 LDLR and four APOB gene mutations had not been reported before. The inclusion of all 2,818 index cases into the national screening program for familial hypercholesterolemia (FH) resulted in the identification of 7,079 relatives who carried a mutation that causes ADH. Screening of the LDLR and APOB genes in clinically diagnosed FH patients resulted in approximately 77% of the patients being identified as carriers of a causative mutation. The population of patients with ADH was divided into three genetically distinct groups: carriers of an LDLR mutation (FH), carriers of an APOB mutation (FDB), and non-LDLR/non-APOB patients (FH3). No differences were found with regard to untreated cholesterol levels, response to therapy, and onset of CVD. However, all groups were at an increased risk for CVD. Therefore, to ultimately identify all individuals with ADH, the identification of new genes and mutations in the genes that cause ADH is of crucial importance for the ongoing national program to identify patients with ADH by genetic cascade screening.
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Affiliation(s)
- Sigrid W Fouchier
- Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Bercovich D, Friedlander Y, Korem S, Houminer A, Hoffman A, Kleinberg L, Shochat C, Leitersdorf E, Meiner V. The association of common SNPs and haplotypes in the CETP and MDR1 genes with lipids response to fluvastatin in familial hypercholesterolemia. Atherosclerosis 2005; 185:97-107. [PMID: 16002074 DOI: 10.1016/j.atherosclerosis.2005.05.025] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2004] [Revised: 05/05/2005] [Accepted: 05/16/2005] [Indexed: 01/09/2023]
Abstract
OBJECTIVE To examine whether genetic polymorphisms in the cholesteryl-ester transfer protein (CETP) and the P-glycoprotein drug transporter (MDR1), are associated with variable lipid response to fluvastatin. METHODS Lipid levels were determined in a compliance-monitored clinical study at baseline and following 20 weeks of treatment with 40 mg dose of fluvastatin in 76 FH patients. CETP and MDR1 SNP genotyping was performed and linear regression was used to examine the associations between common SNPs and haplotypes and lipid response. RESULTS Treatment with 40 mg of fluvastatin resulted in mean low density lipoprotein cholesterol (LDL-C) reduction of 21.5%; mean triglyceride (TG) reduction of 8.3%; and a mean high-density lipoprotein cholesterol (HDL-C) increase of 13.4%. Five tagging SNPs in both genes were used to reconstruct five and six haplotypes accounting for 71.4% and 90.2% of the observed haplotypes in the CETP and MDR1 genes, respectively. CETP-H13 and MDR1-h4 were associated with an increase in LDL-C response. CETP-H5 was significantly associated with decreased TG and HDL-C response, whereas MDR1-h10 was associated with decreased TG response. A multivariate regression model indicated an independent additive effect of CETP-H5 and MDR1-h10 on the level of TG response. CONCLUSIONS CETP and MDR1 have independent effects on lipid changes following fluvastatin treatment. The results of this study may lead to an improved understanding of the genetic determinants of lipids response to treatment.
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Affiliation(s)
- Dani Bercovich
- The Laboratory for Molecular Genetics and Pharmacogenetics, Migal-Galilee Technology Center, Kiryat-Shmona, Israel
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Love DR. Limb girdle muscular dystrophy: use of dHPLC and direct sequencing to detect sarcoglycan gene mutations in a New Zealand cohort. Clin Genet 2004. [PMID: 15032976 DOI: 10.1111/j..2004.00193.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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