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Borg SÁ, Joensen AM, Nielsen MRS, Olsen ÁW, Lolas IBY, Okkels H, Lundbye-Christensen S, Schmidt EB, Bork CS. Possible explanations for the common clinical familial hypercholesterolemia phenotypes in the Faroe Islands. J Clin Lipidol 2023; 17:633-642. [PMID: 37482509 DOI: 10.1016/j.jacl.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 06/18/2023] [Accepted: 06/19/2023] [Indexed: 07/25/2023]
Abstract
BACKGROUND The prevalence of clinical familial hypercholesterolemia (FH) is very high in the Faroe Islands, but the possible causes are unknown. OBJECTIVES We aimed to describe potential genetic causes of FH in the Faroe Islands and to investigate whether levels of lipoprotein(a) and measures of dietary habits were associated with clinical FH in the Faroe Islands. METHODS In this case-control study, we identified potential clinical FH cases aged 18-75 years registered within a nationwide clinical laboratory database in the Faroe Islands and invited them for diagnostic evaluation according to clinical FH scoring systems. Controls were identified in the background population. Lipoprotein(a) was measured in plasma, while the fatty acid composition was determined in adipose tissue. The habitual diet of the participants was assessed using a food frequency questionnaire. Genetic testing for FH and polygenic variants was performed in a selection of clinical FH cases. RESULTS A total of 121 clinical FH cases and 123 age- and sex-matched controls were recruited. We found a very low frequency of monogenic FH (2.5%), but a high level of polygenic FH (63%) in those genetically tested (67%). High levels of plasma lipoprotein(a) were associated with high odds of clinical FH. Clinical FH cases had a lower intake of saturated fatty acids (SFAs) measured by a high fat-score and a lower content of SFAs in adipose tissue compared with controls. CONCLUSION The high prevalence of FH in the Faroe Islands may be due to polygenic causes of hypercholesterolemia and to a lesser extent other genetic factors and elevated plasma lipoprotein(a) levels.
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Affiliation(s)
- Sanna Á Borg
- Department of Medicine, National Hospital of the Faroe Islands, Tórshavn, Faroe Islands.
| | | | | | - Ása Wraae Olsen
- Department of Medicine, National Hospital of the Faroe Islands, Tórshavn, Faroe Islands
| | | | - Henrik Okkels
- Department of Molecular Diagnostics, Aalborg University Hospital, Aalborg, Denmark
| | | | - Erik Berg Schmidt
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Borg SÁ, Nielsen MRS, Søgaard P, Lundbye-Christensen S, Jóanesarson J, Zaremba T, Kollslíð R, Schmidt EB, Joensen AM, Bork CS. Familial hypercholesterolaemia: a study protocol for identification and investigation of potential causes and markers of subclinical coronary artery disease in the Faroe Islands. BMJ Open 2022; 12:e050857. [PMID: 35414540 PMCID: PMC9006835 DOI: 10.1136/bmjopen-2021-050857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
INTRODUCTION Familial hypercholesterolaemia (FH) is the most common monogenic autosomal dominant genetic disorder and is associated with a high risk of premature atherosclerotic cardiovascular disease. The prevalence of FH has been reported to be particularly high in certain founder populations. The population of the Faroe Islands is a founder population, but the prevalence of FH has never been investigated here. We aim to assess the prevalence of FH and to describe the genetic and clinical characteristics and potential causes of FH in the Faroe Islands. Furthermore, we aim to investigate whether indicators of subclinical coronary artery disease are associated with FH. METHODS AND ANALYSIS The prevalence of FH will be estimated based on an electronic nationwide laboratory database that includes all measurements of plasma lipid levels in the Faroe Islands since 2006. Subsequently, we will identify and invite subjects aged between 18 and 75 years registered with a plasma low-density lipoprotein cholesterol above 6.7 mmol/L for diagnostic evaluation. Eligible FH cases will be matched to controls on age and sex. We aim to include 120 FH cases and 120 controls.Detailed information will be collected using questionnaires and interviews, and a physical examination will be undertaken. An adipose tissue biopsy and blood samples for genetic testing, detailed lipid analyses and samples for storage in a biobank for future research will be collected. Furthermore, FH cases and controls will be invited to have a transthoracic echocardiography and a cardiac CT performed. ETHICS AND DISSEMINATION The project has been approved by the Ethical Committee and the Data Protection Agency of the Faroe Islands. The project is expected to provide important information, which will be published in international peer-reviewed journals.
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Affiliation(s)
- Sanna Á Borg
- Department of Medicine, National Hospital of the Faroe Islands, Torshavn, Faroe Islands
| | | | - Peter Søgaard
- Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark
| | - Søren Lundbye-Christensen
- Unit of Clinical Biostatistics, Aalborg University Hospital, Aalborg, Denmark
- Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark
| | - Jan Jóanesarson
- Department of Medicine, National Hospital of the Faroe Islands, Torshavn, Faroe Islands
| | - Tomas Zaremba
- Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark
| | - Rudi Kollslíð
- Department of Medicine, National Hospital of the Faroe Islands, Torshavn, Faroe Islands
| | - Erik Berg Schmidt
- Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Borg SÁ, Sørensen Bork C, Skjelbo Nielsen MR, Berg Schmidt E, Kollslíð R, Lundbye-Christensen S, Joensen AM. Lipids, lipoproteins and prevalence of familial hypercholesterolemia in the Faroe Islands - Results from a nationwide laboratory database. ATHEROSCLEROSIS PLUS 2022; 48:55-59. [PMID: 36644563 PMCID: PMC9833255 DOI: 10.1016/j.athplu.2022.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/12/2022] [Accepted: 03/18/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND AND AIMS Familial hypercholesterolemia (FH) is one of the most common hereditary disorders. The population of the Faroe Islands was established by few founders, and genetic drift may have influenced lipid levels. The aim of this study was to describe the lipid distribution by providing age and sex-specific lipid values and to investigate the prevalence of FH in the Faroe Islands. METHODS We used an electronic nationwide laboratory database that included lipid measurements obtained in the Faroe Islands between January 2006 and September 2020. Percentiles of lipid levels were calculated using quantile regression. The prevalence of FH was estimated according to the Make Early Diagnosis Prevent Early Death (MEDPED) diagnostic criteria and according to the LDL-C cut-off levels included in the Dutch Lipid Clinic Network (DLCN) criteria using generalized linear models with robust variance. RESULTS According to the MEDPED age-specific cut-offs for LDL-C, a total of 216 subjects met the criteria for definite FH among 30,711 individuals corresponding to a prevalence of 0.70% (1:142). According to the LDL-C cut-offs included in the DLCN criteria, a total of 3,823 (1:8) subjects could be classified as having possible FH, and 10 (1:3,071) subjects could be classified as probable FH corresponding to a prevalence of 12.4% and 0.03%, respectively. Also, we found significant differences in lipid levels according to sex and age groups. CONCLUSION The Faroe Islands might represent a founder population with a prevalence of possible FH as high as 1 in 8. Further investigation of genetic and clinical characteristics of FH in the Faroe Islands is needed.
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Affiliation(s)
- Sanna á Borg
- Department of Medicine, National Hospital of the Faroe Islands, Faroe Islands
| | | | | | | | - Rudi Kollslíð
- Department of Medicine, National Hospital of the Faroe Islands, Faroe Islands
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Establishing the Mutational Spectrum of Hungarian Patients with Familial Hypercholesterolemia. Genes (Basel) 2022; 13:genes13010153. [PMID: 35052492 PMCID: PMC8775528 DOI: 10.3390/genes13010153] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/11/2022] [Accepted: 01/11/2022] [Indexed: 02/05/2023] Open
Abstract
Familial hypercholesterolemia (FH) is one of the most common autosomal, dominantly inherited diseases affecting cholesterol metabolism, which, in the absence of treatment, leads to the development of cardiovascular complications. The disease is still underdiagnosed, even though an early diagnosis would be of great importance for the patient to receive proper treatment and to prevent further complications. No studies are available describing the genetic background of Hungarian FH patients. In this work, we present the clinical and molecular data of 44 unrelated individuals with suspected FH. Sequencing of five FH-causing genes (LDLR, APOB, PCSK9, LDLRAP1 and STAP1) has been performed by next-generation sequencing (NGS). In cases where a copy number variation (CNV) has been detected by NGS, confirmation by multiplex ligation-dependent probe amplification (MLPA) has also been performed. We identified 47 causal or potentially causal (including variants of uncertain significance) LDLR and APOB variants in 44 index patients. The most common variant in the APOB gene was the c.10580G>A p.(Arg3527Gln) missense alteration, this being in accordance with literature data. Several missense variants in the LDLR gene were detected in more than one index patient. LDLR variants in the Hungarian population largely overlap with variants detected in neighboring countries.
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Björnsson E, Thorgeirsson G, Helgadóttir A, Thorleifsson G, Sveinbjörnsson G, Kristmundsdóttir S, Jónsson H, Jónasdóttir A, Jónasdóttir Á, Sigurðsson Á, Guðnason T, Ólafsson Í, Sigurðsson EL, Sigurðardóttir Ó, Viðarsson B, Baldvinsson M, Bjarnason R, Danielsen R, Matthíasson SE, Thórarinsson BL, Grétarsdóttir S, Steinthórsdóttir V, Halldórsson BV, Andersen K, Arnar DO, Jónsdóttir I, Guðbjartsson DF, Hólm H, Thorsteinsdóttir U, Sulem P, Stefánsson K. Large-Scale Screening for Monogenic and Clinically Defined Familial Hypercholesterolemia in Iceland. Arterioscler Thromb Vasc Biol 2021; 41:2616-2628. [PMID: 34407635 PMCID: PMC8454500 DOI: 10.1161/atvbaha.120.315904] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 08/02/2021] [Indexed: 01/07/2023]
Abstract
Objective: Familial hypercholesterolemia (FH) is traditionally defined as a monogenic disease characterized by severely elevated LDL-C (low-density lipoprotein cholesterol) levels. In practice, FH is commonly a clinical diagnosis without confirmation of a causative mutation. In this study, we sought to characterize and compare monogenic and clinically defined FH in a large sample of Icelanders. Approach and Results: We whole-genome sequenced 49 962 Icelanders and imputed the identified variants into an overall sample of 166 281 chip-genotyped Icelanders. We identified 20 FH mutations in LDLR, APOB, and PCSK9 with combined prevalence of 1 in 836. Monogenic FH was associated with severely elevated LDL-C levels and increased risk of premature coronary disease, aortic valve stenosis, and high burden of coronary atherosclerosis. We used a modified version of the Dutch Lipid Clinic Network criteria to screen for the clinical FH phenotype among living adult participants (N=79 058). Clinical FH was found in 2.2% of participants, of whom only 5.2% had monogenic FH. Mutation-negative clinical FH has a strong polygenic basis. Both individuals with monogenic FH and individuals with mutation-negative clinical FH were markedly undertreated with cholesterol-lowering medications and only a minority attained an LDL-C target of <2.6 mmol/L (<100 mg/dL; 11.0% and 24.9%, respectively) or <1.8 mmol/L (<70 mg/dL; 0.0% and 5.2%, respectively), as recommended for primary prevention by European Society of Cardiology/European Atherosclerosis Society cholesterol guidelines. Conclusions: Clinically defined FH is a relatively common phenotype that is explained by monogenic FH in only a minority of cases. Both monogenic and clinical FH confer high cardiovascular risk but are markedly undertreated.
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Affiliation(s)
- Eythór Björnsson
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
- Faculty of Medicine, University of Iceland, Reykjavík (E.B., E.L.S., R.B., K.A., D.O.A., I.J., U.T., K.S.)
- Department of Internal Medicine (E.B.), Landspítali-The National University Hospital of Iceland, Reykjavík
| | - Guðmundur Thorgeirsson
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
- Division of Cardiology, Department of Internal Medicine (G. Thorgeirsson, R.D., K.A., D.O.A.), Landspítali-The National University Hospital of Iceland, Reykjavík
| | - Anna Helgadóttir
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Guðmar Thorleifsson
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Garðar Sveinbjörnsson
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Snaedís Kristmundsdóttir
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Hákon Jónsson
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Aðalbjörg Jónasdóttir
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Áslaug Jónasdóttir
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Ásgeir Sigurðsson
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | | | - Ísleifur Ólafsson
- Department of Clinical Biochemistry (I.O.), Landspítali-The National University Hospital of Iceland, Reykjavík
| | - Emil L. Sigurðsson
- Faculty of Medicine, University of Iceland, Reykjavík (E.B., E.L.S., R.B., K.A., D.O.A., I.J., U.T., K.S.)
- Development Centre for the Primary Care, Reykjavík, Iceland (E.L.S.)
| | | | - Brynjar Viðarsson
- Department of Hematology (B.V.), Landspítali-The National University Hospital of Iceland, Reykjavík
- The Laboratory in Mjódd, Reykjavík, Iceland (B.V.)
| | | | - Ragnar Bjarnason
- Faculty of Medicine, University of Iceland, Reykjavík (E.B., E.L.S., R.B., K.A., D.O.A., I.J., U.T., K.S.)
- Children’s Medical Center (R.B.), Landspítali-The National University Hospital of Iceland, Reykjavík
| | - Ragnar Danielsen
- Division of Cardiology, Department of Internal Medicine (G. Thorgeirsson, R.D., K.A., D.O.A.), Landspítali-The National University Hospital of Iceland, Reykjavík
| | | | - Björn L. Thórarinsson
- Department of Neurology (B.L.T.), Landspítali-The National University Hospital of Iceland, Reykjavík
| | - Sólveig Grétarsdóttir
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Valgerður Steinthórsdóttir
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Bjarni V. Halldórsson
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Karl Andersen
- Faculty of Medicine, University of Iceland, Reykjavík (E.B., E.L.S., R.B., K.A., D.O.A., I.J., U.T., K.S.)
- Division of Cardiology, Department of Internal Medicine (G. Thorgeirsson, R.D., K.A., D.O.A.), Landspítali-The National University Hospital of Iceland, Reykjavík
| | - Davíð O. Arnar
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
- Faculty of Medicine, University of Iceland, Reykjavík (E.B., E.L.S., R.B., K.A., D.O.A., I.J., U.T., K.S.)
- Division of Cardiology, Department of Internal Medicine (G. Thorgeirsson, R.D., K.A., D.O.A.), Landspítali-The National University Hospital of Iceland, Reykjavík
| | - Ingileif Jónsdóttir
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
- Faculty of Medicine, University of Iceland, Reykjavík (E.B., E.L.S., R.B., K.A., D.O.A., I.J., U.T., K.S.)
| | - Daníel F. Guðbjartsson
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
- School of Engineering and Natural Sciences, University of Iceland, Reykjavík (D.F.G.)
| | - Hilma Hólm
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Unnur Thorsteinsdóttir
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
- Faculty of Medicine, University of Iceland, Reykjavík (E.B., E.L.S., R.B., K.A., D.O.A., I.J., U.T., K.S.)
| | - Patrick Sulem
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
| | - Kári Stefánsson
- deCODE genetics/Amgen, Inc, Reykjavík, Iceland (E.B., G. Thorgeirsson, A.H., G. Thorleifsson, G.S., S.K., H.J., Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, A.S., S.G., V.S., B.V.H., D.O.A., I.J., D.F.G., H.H., U.T., P.S., K.S.)
- Faculty of Medicine, University of Iceland, Reykjavík (E.B., E.L.S., R.B., K.A., D.O.A., I.J., U.T., K.S.)
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6
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Bjornsson E, Gunnarsdottir K, Halldorsson GH, Sigurdsson A, Arnadottir GA, Jonsson H, Olafsdottir EF, Niehus S, Kehr B, Sveinbjörnsson G, Gudmundsdottir S, Helgadottir A, Andersen K, Thorleifsson G, Eyjolfsson GI, Olafsson I, Sigurdardottir O, Saemundsdottir J, Jonsdottir I, Magnusson OT, Masson G, Stefansson H, Gudbjartsson DF, Thorgeirsson G, Holm H, Halldorsson BV, Melsted P, Norddahl GL, Sulem P, Thorsteinsdottir U, Stefansson K. Lifelong Reduction in LDL (Low-Density Lipoprotein) Cholesterol due to a Gain-of-Function Mutation in LDLR. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2020; 14:e003029. [PMID: 33315477 DOI: 10.1161/circgen.120.003029] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Loss-of-function mutations in the LDL (low-density lipoprotein) receptor gene (LDLR) cause elevated levels of LDL cholesterol and premature cardiovascular disease. To date, a gain-of-function mutation in LDLR with a large effect on LDL cholesterol levels has not been described. Here, we searched for sequence variants in LDLR that have a large effect on LDL cholesterol levels. METHODS We analyzed whole-genome sequencing data from 43 202 Icelanders. Single-nucleotide polymorphisms and structural variants including deletions, insertions, and duplications were genotyped using whole-genome sequencing-based data. LDL cholesterol associations were carried out in a sample of >100 000 Icelanders with genetic information (imputed or whole-genome sequencing). Molecular analyses were performed using RNA sequencing and protein expression assays in Epstein-Barr virus-transformed lymphocytes. RESULTS We discovered a 2.5-kb deletion (del2.5) overlapping the 3' untranslated region of LDLR in 7 heterozygous carriers from a single family. Mean level of LDL cholesterol was 74% lower in del2.5 carriers than in 101 851 noncarriers, a difference of 2.48 mmol/L (96 mg/dL; P=8.4×10-8). Del2.5 results in production of an alternative mRNA isoform with a truncated 3' untranslated region. The truncation leads to a loss of target sites for microRNAs known to repress translation of LDLR. In Epstein-Barr virus-transformed lymphocytes derived from del2.5 carriers, expression of alternative mRNA isoform was 1.84-fold higher than the wild-type isoform (P=0.0013), and there was 1.79-fold higher surface expression of the LDL receptor than in noncarriers (P=0.0086). We did not find a highly penetrant detrimental impact of lifelong very low levels of LDL cholesterol due to del2.5 on health of the carriers. CONCLUSIONS Del2.5 is the first reported gain-of-function mutation in LDLR causing a large reduction in LDL cholesterol. These data point to a role for alternative polyadenylation of LDLR mRNA as a potent regulator of LDL receptor expression in humans.
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Affiliation(s)
- Eythor Bjornsson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland.,Faculty of Medicine (E.B., K.A., I.J., U.T., K.S.), University of Iceland.,Department of Internal Medicine (E.B., E.F.O.), Division of Cardiology, Department of Internal Medicine (K.A., G. Thorgeirsson), Landspítali - The National University Hospital of Iceland, Reykjavík
| | - Kristbjorg Gunnarsdottir
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Gisli H Halldorsson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Asgeir Sigurdsson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Gudny A Arnadottir
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Hakon Jonsson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Eva F Olafsdottir
- Department of Internal Medicine (E.B., E.F.O.), Division of Cardiology, Department of Internal Medicine (K.A., G. Thorgeirsson), Landspítali - The National University Hospital of Iceland, Reykjavík
| | - Sebastian Niehus
- Berlin Institute of Health (S.N., B.K.), Humboldt-Universität zu Berlin & Berlin Institute of Health, Berlin, Germany.,Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin (S.N., B.K.), Humboldt-Universität zu Berlin & Berlin Institute of Health, Berlin, Germany
| | - Birte Kehr
- Berlin Institute of Health (S.N., B.K.), Humboldt-Universität zu Berlin & Berlin Institute of Health, Berlin, Germany.,Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin (S.N., B.K.), Humboldt-Universität zu Berlin & Berlin Institute of Health, Berlin, Germany
| | - Gardar Sveinbjörnsson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Steinunn Gudmundsdottir
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Anna Helgadottir
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Karl Andersen
- Faculty of Medicine (E.B., K.A., I.J., U.T., K.S.), University of Iceland.,Department of Internal Medicine (E.B., E.F.O.), Division of Cardiology, Department of Internal Medicine (K.A., G. Thorgeirsson), Landspítali - The National University Hospital of Iceland, Reykjavík
| | - Gudmar Thorleifsson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland.,Department of Internal Medicine (E.B., E.F.O.), Division of Cardiology, Department of Internal Medicine (K.A., G. Thorgeirsson), Landspítali - The National University Hospital of Iceland, Reykjavík
| | | | - Isleifur Olafsson
- Department of Clinical Biochemistry (I.O.), Landspítali - The National University Hospital of Iceland, Reykjavík
| | | | - Jona Saemundsdottir
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Ingileif Jonsdottir
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland.,Faculty of Medicine (E.B., K.A., I.J., U.T., K.S.), University of Iceland
| | - Olafur Th Magnusson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Gisli Masson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Hreinn Stefansson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Daniel F Gudbjartsson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland.,School of Engineering and Natural Sciences (D.F.G., P.M.), University of Iceland
| | - Gudmundur Thorgeirsson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland.,Department of Internal Medicine (E.B., E.F.O.), Division of Cardiology, Department of Internal Medicine (K.A., G. Thorgeirsson), Landspítali - The National University Hospital of Iceland, Reykjavík
| | - Hilma Holm
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Bjarni V Halldorsson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland.,School of Science and Engineering, Reykjavík University, Iceland (B.V.H.)
| | - Pall Melsted
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland.,School of Engineering and Natural Sciences (D.F.G., P.M.), University of Iceland
| | - Gudmundur L Norddahl
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Patrick Sulem
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland
| | - Unnur Thorsteinsdottir
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland.,Faculty of Medicine (E.B., K.A., I.J., U.T., K.S.), University of Iceland
| | - Kari Stefansson
- deCODE genetics/Amgen, Inc (E.B., K.G., G.H.H., A.S., G.A.A., H.J., G.S., S.G., A.H., G. Thorleifsson, J.S., I.J., O.T.M., G.M., H.S., D.F.G., G. Thorgeirsson, H.H., B.V.H., P.M., G.L.N., P.S., U.T., K.S.), University of Iceland.,Faculty of Medicine (E.B., K.A., I.J., U.T., K.S.), University of Iceland
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7
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Kellogg G, Thorsson B, Cai Y, Wisotzkey R, Pollock A, Akana M, Fox R, Jansen M, Gudmundsson EF, Patel B, Chang C, Jaremko M, Puig O, Gudnason V, Emilsson V. Molecular screening of familial hypercholesterolemia in Icelanders. Scandinavian Journal of Clinical and Laboratory Investigation 2020; 80:508-514. [DOI: 10.1080/00365513.2020.1795919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
| | | | - Ying Cai
- Phosphorus Diagnostics, New York, NY, USA
| | | | | | | | | | | | | | | | | | | | - Oscar Puig
- Phosphorus Diagnostics, New York, NY, USA
| | - Vilmundur Gudnason
- Icelandic Heart Association, Kopavogur, Iceland
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Valur Emilsson
- Icelandic Heart Association, Kopavogur, Iceland
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland
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8
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Jin W, Zhang Q, Wang B, Pan L, Qin H, Yang D, Zhou X, Du Y, Lin L, Kutryk MJ. Cascade screening for familial hypercholesterolemia-identification of the C308Y mutation in multiple family members and relatives for the first time in mainland China. BMC MEDICAL GENETICS 2019; 20:173. [PMID: 31706281 PMCID: PMC6842482 DOI: 10.1186/s12881-019-0901-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 10/09/2019] [Indexed: 12/31/2022]
Abstract
Background Familial hypercholesterolemia (FH), an autosomal dominant genetic disorder, is underdiagnosed and undertreated. The majority of FH cases are caused by low density lipoprotein receptor (LDL-R) gene mutations. The C308Y mutation in LDL-R results in approximately 70% loss of LDL-R activity, leading to the elevation of low density lipoprotein-cholesterol (LDL-C) and an increased risk of premature coronary heart disease (CHD). The aim of this study was to identify FH cases by cascade screening in family members and relatives of a 37-year old male with premature CHD and hypercholesterolemia. Methods Clinical exam, blood lipid profiling and genomic DNA sequencing of all exons of LDL-R were performed for the proband and his 14 family members and relatives. FH diagnosis was carried out using the Dutch Lipid Clinic Network (DLCN) criteria. Results Lipid profiling showed that 9 individuals, including the proband, had hypercholesterolemia. All these 9 subjects had a G > A substitution at nucleotide 986 in exon 7 resulting in the C308Y mutation as determined by DNA sequencing, and all those carrying the mutation were diagnosed as having definite FH under the DLCN criteria. However, most (7/9) did not have suggestive clinical manifestations of CHD. Conclusions The C308Y mutation was discovered in multiple family members and relatives for the first time in mainland China. Cascade screening is key for the confirmatory diagnosis of FH. Our hypothesis that the C308Y is a common variant in the population of Southern China origin warrants further validation by screening for the C308Y mutation in a large population.
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Affiliation(s)
- Weirong Jin
- Shanghai Human Genome Center, Shanghai, China
| | - Qiuwang Zhang
- Division of Cardiology, Keenan Research Center for Biomedical Science, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Bei Wang
- Department of Cardiology, the Third People's Hospital of Hainan Province, 1154 Jiefang Road, Sanya, 572000, Hainan Province, China
| | - Lili Pan
- Department of Cardiology, the Third People's Hospital of Hainan Province, 1154 Jiefang Road, Sanya, 572000, Hainan Province, China
| | - Hongyou Qin
- Shanghai Human Genome Center, Shanghai, China
| | - Daying Yang
- Department of Cardiology, the Third People's Hospital of Hainan Province, 1154 Jiefang Road, Sanya, 572000, Hainan Province, China
| | - Xiangqun Zhou
- Department of Cardiology, the Third People's Hospital of Hainan Province, 1154 Jiefang Road, Sanya, 572000, Hainan Province, China
| | - Yongcai Du
- Department of Cardiology, the Third People's Hospital of Hainan Province, 1154 Jiefang Road, Sanya, 572000, Hainan Province, China
| | - Ling Lin
- Department of Cardiology, the Third People's Hospital of Hainan Province, 1154 Jiefang Road, Sanya, 572000, Hainan Province, China.
| | - Michael J Kutryk
- Division of Cardiology, Keenan Research Center for Biomedical Science, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
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9
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Sun D, Zhou BY, Li S, Sun NL, Hua Q, Wu SL, Cao YS, Guo YL, Wu NQ, Zhu CG, Gao Y, Cui CJ, Liu G, Li JJ. Genetic basis of index patients with familial hypercholesterolemia in Chinese population: mutation spectrum and genotype-phenotype correlation. Lipids Health Dis 2018; 17:252. [PMID: 30400955 PMCID: PMC6220500 DOI: 10.1186/s12944-018-0900-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 10/24/2018] [Indexed: 11/18/2022] Open
Abstract
Background Although there have been many reports in the genetics of familial hypercholesterolemia (FH) worldwide, studies in regard of Chinese population are lacking. In this multi-center study, we aim to characterize the genetic spectrum of FH in Chinese population, and examine the genotype-phenotype correlations in detail. Methods A total of 285 unrelated index cases from China with clinical FH were consecutively recruited. Next-generation sequencing and bioinformatics tools were used for mutation detection of LDLR, APOB and PCSK9 genes and genetic analysis. Results Overall, the detection rate is 51.9% (148/285) in the unrelated index cases with a total of 119 risk variants identified including 84 in the LDLR gene, 31 in APOB and 4 in PCSK9 gene. Twenty-eight variants were found in more than one individual and LDLR c.1448G > A (p. W483X) was most frequent one detected in 9 patients. Besides, we found 8 (7 LDLR and 1 APOB) novel variants referred as “pathogenic (or likely pathogenic) variants” according to in silico analysis. In the phenotype analysis, patients with LDLR null mutation had significantly higher LDL cholesterol level than LDLR defective and APOB/PCSK9 mutation carriers and those with no mutations (p < 0.001). Furthermore, 13 double heterozygotes, 16 compound heterozygotes and 5 true LDLR homozygotes were identified and the true LDLR homozygotes had the most severe phenotypes. Conclusions The present study confirmed the heterogeneity of FH genetics in the largest Chinese cohort, which could replenish the knowledge of mutation spectrum and contribute to early screening and disease management.
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Affiliation(s)
- Di Sun
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Bing-Yang Zhou
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Sha Li
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Ning-Ling Sun
- Department of Cardiology, Peking University People's Hospital, Beijing, 100044, China
| | - Qi Hua
- Department of Cardiology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
| | - Shu-Lin Wu
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, 510080, China
| | - Yun-Shan Cao
- Department of Cardiology, Gansu Provincial People's Hospital, Lanzhou, 730000, Gansu, China
| | - Yuan-Lin Guo
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Na-Qiong Wu
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Cheng-Gang Zhu
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Ying Gao
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Chuan-Jue Cui
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Geng Liu
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Jian-Jun Li
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China.
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10
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Paththinige CS, Rajapakse JRDK, Constantine GR, Sem KP, Singaraja RR, Jayasekara RW, Dissanayake VHW. Spectrum of low-density lipoprotein receptor (LDLR) mutations in a cohort of Sri Lankan patients with familial hypercholesterolemia - a preliminary report. Lipids Health Dis 2018; 17:100. [PMID: 29720182 PMCID: PMC5932885 DOI: 10.1186/s12944-018-0763-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 04/26/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hypercholesterolemia is a major determinant of cardiovascular disease-associated morbidity and mortality. Mutations in the LDL-receptor (LDLR) gene are implicated in the majority of the cases with familial hypercholesterolemia (FH). However, the spectrum of mutations in the LDLR gene in Sri Lankan patients has not been investigated. The objective of this study was to report the frequency and spectrum of variants in LDLR in a cohort of Sri Lankan patients with FH. METHODS A series of consecutive patients with FH, diagnosed according to Modified Simon Broome criteria or Dutch Lipid Clinic Network criteria at the University Medical Unit, Colombo, were recruited. Clinical data was recorded. DNA was extracted from peripheral blood samples. The LDLR gene was screened for genetic variants by Sanger sequencing. RESULTS A total of 27 patients [13 (48%) males, 14 (52%) females; age range 24-73 years] were tested. Clinical features found among these 27 patients were: xanthelasma in 5 (18.5%), corneal arcus in 1 (3.7%), coronary artery disease (CAD) in 10 (37%), and a family history of hypercholesterolemia and/or CAD in 24 (88.9%) patients. In the entire cohort, mean total cholesterol was 356.8 mg/dl (±66.4) and mean LDL-cholesterol was 250.3 mg/dl (±67.7). Sanger sequencing of the 27 patients resulted in the identification of known pathogenic missense mutations in 5 (18.5%) patients. Four were heterozygotes for 1 mutation each. They were c.682G > C in 2 patients, c.1720C > A in 1 patient, and c.1855 T > A in 1 patient. One patient with severe FH phenotypes was a compound heterozygote for one known mutation, c.2289G > T, and another missense variant, c.1670C > G (p.Thr557Ser), with unknown functional impact. This latter variant has not been reported in any other population previously. CONCLUSIONS The frequency of known mutations in the LDLR gene in this cohort of patients was markedly low compared to frequencies reported in other populations. This highlights the likelihood of a complex, polygenic inheritance of FH in Sri Lankan patients, indicating the need for a comprehensive genetic evaluation that includes the screening for mutations in other genes that cause FH, such as APOB, PCSK9, and LDLRAP1.
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Affiliation(s)
- C S Paththinige
- Human Genetics Unit, Faculty of Medicine, University of Colombo, Kynsey Road, Colombo, 00800, Sri Lanka. .,Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Anuradhapura, Sri Lanka.
| | - J R D K Rajapakse
- Human Genetics Unit, Faculty of Medicine, University of Colombo, Kynsey Road, Colombo, 00800, Sri Lanka
| | - G R Constantine
- Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | - K P Sem
- Translational Laboratory in Genetic Medicine, Agency for Science Technology and Research, National University of Singapore, Singapore, Singapore
| | - R R Singaraja
- Translational Laboratory in Genetic Medicine, Agency for Science Technology and Research, National University of Singapore, Singapore, Singapore
| | - R W Jayasekara
- Human Genetics Unit, Faculty of Medicine, University of Colombo, Kynsey Road, Colombo, 00800, Sri Lanka
| | - V H W Dissanayake
- Human Genetics Unit, Faculty of Medicine, University of Colombo, Kynsey Road, Colombo, 00800, Sri Lanka
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11
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Alallaf F, H.Nazar FA, Alnefaie M, Almaymuni A, Rashidi OM, Alhabib K, Alnouri F, Alama MN, Athar M, Awan Z. The Spectrum of Familial Hypercholesterolemia (FH) in Saudi Arabia: Prime Time for Patient FH Registry. Open Cardiovasc Med J 2017; 11:66-75. [PMID: 28868092 PMCID: PMC5564019 DOI: 10.2174/1874192401711010066] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 04/27/2017] [Accepted: 05/17/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Familial hypercholesterolemia (FH) is a life-threatening inherited condition. Untreated patients have the risk to develop raised plasma levels of cholesterol, atherosclerosis and cardiovascular disease (CVD). If diagnosed and treated early in life, the pathological consequences due to atherosclerosis could be avoided and patients with FH can have an anticipated normal life. Mounting evidence suggests that FH is underdiagnosed and undertreated in all populations. The underlying molecular basis of FH is the presence of mutations in one or more genes in the low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB) or proprotein convertase subtilisin/kexin 9 (PCSK9). However, their prevalence is largely unknown in Saudi Arabia but given the high rates of consanguinity, the prevalence appears to be higher. Furthermore, the high prevalence of obesity and diabetes mellitus in Saudi Arabia increases the vascular disease burden in FH cases by adding additional CVD risk factors. OBJECTIVE This article explores the spectrum of FH-causing mutations in the highly consanguineous Saudi community, the need for establishing the Saudi FH registry, the challenges in creating gene databases, and cascade screening. CONCLUSION The establishment of FH registry and genetic testing should raise awareness not only among healthcare professionals, but the general population as well. It also helps to provide the best treatment regimen in a cost effective manner to this under-recognised population of FH patients.
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Affiliation(s)
- Faisal Alallaf
- Department of Medical Genetics, Faculty of Medicine, Umm Al-Qura University, Mekkah. Saudi Arabia
| | - Fatima Amanullah H.Nazar
- Department of Biology, Genomic and Biotechnology Section, Faculty of Science, King Abdulaziz University, Jeddah. Saudi Arabia
| | - Majed Alnefaie
- Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah. Saudi Arabia
| | - Adel Almaymuni
- Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah. Saudi Arabia
| | - Omran Mohammed Rashidi
- Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah. Saudi Arabia
| | - Khalid Alhabib
- Interventional Cardiology, King Fahad Cardiac Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Fahad Alnouri
- Cardiovascular Prevention and Rehabilitation Unit, Prince Sultan Cardiac Centre, Riyadh, Saudi Arabia
| | - Mohamed-Nabil Alama
- Adult interventional cardiology, Cardiology unit, King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia
| | - Mohammad Athar
- Department of Science and Technology, Umm Al-Qura University, Mekkah, Saudi Arabia
| | - Zuhier Awan
- Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah. Saudi Arabia
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TICHÝ L, FAJKUSOVÁ L, ZAPLETALOVÁ P, SCHWARZOVÁ L, VRABLÍK M, FREIBERGER T. Molecular Genetic Background of an Autosomal Dominant Hypercholesterolemia in the Czech Republic. Physiol Res 2017; 66:S47-S54. [DOI: 10.33549/physiolres.933587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Autosomal dominant hypercholesterolemia (ADH), more known as familial hypercholesterolemia (FH), is a lipid metabolism disorder characterized by an elevation in low-density lipoprotein cholesterol (LDL-C) and increased risk for cardiovascular disease. In this study, we assessed a spectrum of mutations causing ADH in 3914 unrelated Czech patients with clinical diagnosis of hypercholesterolemia. Samples have been collected within the framework of the MedPed project running in the Czech Republic since 1998. So far we have found 432 patients (11.0 %) with the APOB gene mutation p.(Arg3527Gln) and 864 patients (22.1 %) with the LDLR gene mutation. In 864 probands carrying the LDLR gene mutation, 182 unique allelic variants were detected. We have identified 14 patients homozygous for mutations in the LDLR or APOB genes. We performed function analyses of p.(Leu15Pro) and p.(Gly20Arg) sequence variations.
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Affiliation(s)
| | | | | | | | | | - T. FREIBERGER
- Centre for Cardiovascular Surgery and Transplantation, Brno, Czech Republic
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13
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GABČOVÁ D, VOHNOUT B, STANÍKOVÁ D, HUČKOVÁ M, KADUROVÁ M, DEBREOVÁ M, KOZÁROVÁ M, FÁBRYOVÁ Ľ, SLOVAK FH STUDY GROUP, STANÍK J, KLIMEŠ I, RAŠLOVÁ K, GAŠPERIKOVÁ D. The Molecular Genetic Background of Familial Hypercholesterolemia: Data From the Slovak Nation-Wide Survey. Physiol Res 2017; 66:75-84. [DOI: 10.33549/physiolres.933348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Familial hypercholesterolemia (FH) is most frequently caused by LDLR or APOB mutations. Therefore, the aim of our study was to examine the genetic background of Slovak patients suspected of FH. Patients with clinical suspicion of FH (235 unrelated probands and 124 family relatives) were recruited throughout Slovakia during the years 2011-2015. The order of DNA analyses in probands was as follows: 1. APOB mutation p.Arg3527Gln by real-time PCR method, 2. direct sequencing of the LDLR gene 3. MLPA analysis of the LDLR gene. We have identified 14 probands and 2 relatives with an APOB mutation p.Arg3527Gln, and 89 probands and 75 relatives with 54 different LDLR mutations. Nine of LDLR mutations were novel (i.e. p.Asp90Glu, c.314-2A>G, p.Asp136Tyr, p.Ser177Pro, p.Lys225_Glu228delinsCysLys, p.Gly478Glu, p.Gly675Trpfs*42, p.Leu680Pro, p.Thr832Argfs*3). This is the first study on molecular genetics of FH in Slovakia encompassing the analysis of whole LDLR gene. Genetic etiology of FH was confirmed in 103 probands (43.8 %). Out of them, 86.4 % of probands carried the LDLR gene mutation and remaining 13.6 % probands carried the p.Arg3527Gln APOB mutation.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - D. GAŠPERIKOVÁ
- DIABGENE Laboratory, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
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14
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Variants with large effects on blood lipids and the role of cholesterol and triglycerides in coronary disease. Nat Genet 2016; 48:634-9. [PMID: 27135400 DOI: 10.1038/ng.3561] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 04/06/2016] [Indexed: 11/08/2022]
Abstract
Sequence variants affecting blood lipids and coronary artery disease (CAD) may enhance understanding of the atherogenicity of lipid fractions. Using a large resource of whole-genome sequence data, we examined rare and low-frequency variants for association with non-HDL cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides in up to 119,146 Icelanders. We discovered 13 variants with large effects (within ANGPTL3, APOB, ABCA1, NR1H3, APOA1, LIPC, CETP, LDLR, and APOC1) and replicated 14 variants. Five variants within PCSK9, APOA1, ANGPTL4, and LDLR associate with CAD (33,090 cases and 236,254 controls). We used genetic risk scores for the lipid fractions to examine their causal relationship with CAD. The non-HDL cholesterol genetic risk score associates most strongly with CAD (P = 2.7 × 10(-28)), and no other genetic risk score associates with CAD after accounting for non-HDL cholesterol. The genetic risk score for non-HDL cholesterol confers CAD risk beyond that of LDL cholesterol (P = 5.5 × 10(-8)), suggesting that targeting atherogenic remnant cholesterol may reduce cardiovascular risk.
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15
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Klančar G, Grošelj U, Kovač J, Bratanič N, Bratina N, Trebušak Podkrajšek K, Battelino T. Universal Screening for Familial Hypercholesterolemia in Children. J Am Coll Cardiol 2015; 66:1250-1257. [PMID: 26361156 DOI: 10.1016/j.jacc.2015.07.017] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/08/2015] [Accepted: 07/02/2015] [Indexed: 01/06/2023]
Abstract
BACKGROUND Individuals with familial hypercholesterolemia (FH) who are untreated have up to 100-fold elevated risk for cardiovascular complications compared with those who are unaffected. Data for identification of FH with a universal screening for hypercholesterolemia in children are lacking. OBJECTIVES This study sought genetic identification of FH from a cohort of children with elevated serum total cholesterol (TC) concentration, detected in a national universal screening for hypercholesterolemia. METHODS Slovenian children born between 1989 and 2009 (n = 272) with TC >6 mmol/l (231.7 mg/dl) or >5 mmol/l (193.1 mg/dl) plus a family history positive for premature cardiovascular complications, identified in a national universal screening for hypercholesterolemia at 5 years of age were genotyped for variants in LDLR, PCSK9, APOB, and APOE. RESULTS Of the referred children, 57.0% carried disease-causing variants for FH: 38.6% in LDLR, 18.4% in APOB, and none in PCSK9. Nine novel disease-causing variants were identified, 8 in LDLR, and 1 in APOB. Of the remaining participants, 43.6% carried the APOE E4 isoform. Estimated detection rate of FH in the universal screening program from 2009 to 2013 was 53.6% (95% confidence interval [CI]: 34.5% to 72.8%), peaking in 2013 with an upper estimated detection rate of 96.3%. Variants in LDLR, APOB, or the APOE E4 isoform occurred in 48.6%, 60.0%, and 76.5%, respectively, of patients with a family history negative for cardiovascular complications. CONCLUSIONS Most participants who were referred from a national database of universal screening results for hypercholesterolemia had genetically confirmed FH. Data for family history may not suffice for reliable identification of patients through selective and cascade screening.
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Affiliation(s)
- Gašper Klančar
- Department of Pediatric Endocrinology, Diabetes and Metabolic Diseases, University Children's Hospital, UMC Ljubljana, Ljubljana, Slovenia; Unit of Special Laboratory Diagnostics, University Children's Hospital, UMC Ljubljana, Ljubljana, Slovenia
| | - Urh Grošelj
- Department of Pediatric Endocrinology, Diabetes and Metabolic Diseases, University Children's Hospital, UMC Ljubljana, Ljubljana, Slovenia
| | - Jernej Kovač
- Unit of Special Laboratory Diagnostics, University Children's Hospital, UMC Ljubljana, Ljubljana, Slovenia
| | - Nevenka Bratanič
- Department of Pediatric Endocrinology, Diabetes and Metabolic Diseases, University Children's Hospital, UMC Ljubljana, Ljubljana, Slovenia
| | - Nataša Bratina
- Department of Pediatric Endocrinology, Diabetes and Metabolic Diseases, University Children's Hospital, UMC Ljubljana, Ljubljana, Slovenia
| | - Katarina Trebušak Podkrajšek
- Unit of Special Laboratory Diagnostics, University Children's Hospital, UMC Ljubljana, Ljubljana, Slovenia; Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Tadej Battelino
- Department of Pediatric Endocrinology, Diabetes and Metabolic Diseases, University Children's Hospital, UMC Ljubljana, Ljubljana, Slovenia; Department of Pediatrics, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
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16
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Gretarsdottir S, Helgason H, Helgadottir A, Sigurdsson A, Thorleifsson G, Magnusdottir A, Oddsson A, Steinthorsdottir V, Rafnar T, de Graaf J, Daneshpour MS, Hedayati M, Azizi F, Grarup N, Jørgensen T, Vestergaard H, Hansen T, Eyjolfsson G, Sigurdardottir O, Olafsson I, Kiemeney LA, Pedersen O, Sulem P, Thorgeirsson G, Gudbjartsson DF, Holm H, Thorsteinsdottir U, Stefansson K. A Splice Region Variant in LDLR Lowers Non-high Density Lipoprotein Cholesterol and Protects against Coronary Artery Disease. PLoS Genet 2015; 11:e1005379. [PMID: 26327206 PMCID: PMC4556698 DOI: 10.1371/journal.pgen.1005379] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 06/22/2015] [Indexed: 01/08/2023] Open
Abstract
Through high coverage whole-genome sequencing and imputation of the identified variants into a large fraction of the Icelandic population, we found four independent signals in the low density lipoprotein receptor gene (LDLR) that associate with levels of non-high density lipoprotein cholesterol (non-HDL-C) and coronary artery disease (CAD). Two signals are novel with respect to association with non-HDL-C and are represented by non-coding low frequency variants (between 2–4% frequency), the splice region variant rs72658867-A in intron 14 and rs17248748-T in intron one. These two novel associations were replicated in three additional populations. Both variants lower non-HDL-C levels (rs72658867-A, non-HDL-C effect = -0.44 mmol/l, Padj = 1.1 × 10−80 and rs17248748-T, non-HDL-C effect = -0.13 mmol/l, Padj = 1.3 × 10−12) and confer protection against CAD (rs72658867-A, OR = 0.76 and Padj = 2.7 × 10−8 and rs17248748-T, OR = 0.92 and Padj = 0.022). The LDLR splice region variant, rs72658867-A, located at position +5 in intron 14 (NM_000527:c.2140+5G>A), causes retention of intron 14 during transcription and is expected to produce a truncated LDL receptor lacking domains essential for function of the receptor. About half of the transcripts generated from chromosomes carrying rs72658867-A are characterized by this retention of the intron. The same variant also increases LDLR mRNA expression, however, the wild type transcripts do not exceed levels in non-carriers. This demonstrates that sequence variants that disrupt the LDL receptor can lower non-HDL-C and protect against CAD. Cholesterol levels in the bloodstream, in particular elevated low-density lipoprotein cholesterol (LDL-C), are strong risk factors for cardiovascular disease, and LDL-C reduction reduces mortality in people at risk. One of the major determinants of plasma LDL-C levels is the low density lipoprotein receptor (LDLR) that acts as a scavenger for cholesterol rich lipoprotein particles. Mutations that disrupt the function of the LDLR or lead to reduction in the number of LDLR usually result in elevated LDL-C in blood. In the current study, we identified, through whole-genome sequencing and imputation into a large fraction of the Icelandic population, four LDLR gene variants that affect non-HDL-C levels (that includes cholesterol in LDL and other pro-atherogenic lipoproteins) and risk of coronary artery disease (CAD). Two variants are known and two are novel. One of them, a splice region variant in intron 14 (rs72658867-A), affects normal splicing and is predicted to generate a truncated LDLR, lacking domains essential for receptor function. Despite this, rs72658867-A lowers non-HDL-C substantially and protects against CAD in the general population, demonstrating that variants that disrupt the LDLR can result in lower cholesterol levels.
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Affiliation(s)
| | - Hannes Helgason
- deCODE Genetics/Amgen, Inc., Reykjavik, Iceland
- School of Engineering and Natural Sciences, University of Iceland, Reykjavik, Iceland
| | - Anna Helgadottir
- deCODE Genetics/Amgen, Inc., Reykjavik, Iceland
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | | | | | | | | | | | | | - Jacqueline de Graaf
- Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands
| | - Maryam S. Daneshpour
- Cellular and Molecular Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran
| | - Mehdi Hedayati
- Cellular and Molecular Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran
| | - Fereidoun Azizi
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran
| | - Niels Grarup
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Torben Jørgensen
- Research Centre for Prevention and Health, The Capital Region of Denmark, Copenhagen, Denmark
- Faculty of Medicine, University of Aalborg, Aalborg, Denmark
- Institute of Public Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Vestergaard
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Torben Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | | | | | - Isleifur Olafsson
- Department of Clinical Biochemistry, Landspitali, National University Hospital, Reykjavik, Iceland
| | - Lambertus A. Kiemeney
- Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands
| | - Oluf Pedersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Gudmundur Thorgeirsson
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland
- Division of Cardiology, Department of Internal Medicine, Landspitali, National University Hospital of Iceland, Reykjavik, Iceland
| | - Daniel F. Gudbjartsson
- deCODE Genetics/Amgen, Inc., Reykjavik, Iceland
- School of Engineering and Natural Sciences, University of Iceland, Reykjavik, Iceland
| | - Hilma Holm
- deCODE Genetics/Amgen, Inc., Reykjavik, Iceland
- Division of Cardiology, Department of Internal Medicine, Landspitali, National University Hospital of Iceland, Reykjavik, Iceland
| | - Unnur Thorsteinsdottir
- deCODE Genetics/Amgen, Inc., Reykjavik, Iceland
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland
- * E-mail: (UT); (KS)
| | - Kari Stefansson
- deCODE Genetics/Amgen, Inc., Reykjavik, Iceland
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland
- * E-mail: (UT); (KS)
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17
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Screening for Familial Hypercholesterolaemia: Universal or Cascade? A Critique of Current FH Recognition Strategies. CURRENT CARDIOVASCULAR RISK REPORTS 2015. [DOI: 10.1007/s12170-014-0434-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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18
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Al-Rasadi K, Al-Waili K, Al-Zidi WAM, Al-Abri AR, Al-Hinai AT, Al-Sabti HA, Al-Tobi S, Al-Zakwani I, Al-Zadjali F, Al-Hashmi K, Banerjee Y. Low-density lipoprotein receptor gene mutation analysis and structure-function correlation in an Omani arab family with familial hypercholesterolemia. Angiology 2013; 65:911-8. [PMID: 24249837 DOI: 10.1177/0003319713510059] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Familial hypercholesterolemia (FH) is an autosomal dominant disorder typified by elevated low-density lipoprotein cholesterol (LDL-C) levels caused by mutations in the LDL receptor (LDLR), apolipoprotein B (ApoB), or proprotein convertase subtilisin/kexin type 9 (PCSK9) genes. Previously, we reported a novel mutation in the exon-3 of LDLR gene, observed in a 9-year-old Omani Arab female. Here, we investigated the mode of inheritance of this mutation and confirmed that FH in this family is due to mutation only in the LDLR and not PCSK9 and ApoB genes. Further, the effect of the mutation has been appraised in silico on the tertiary structure of LDLR. A model of the mutant LDLR has been constructed using the coordinates of the wild-type LDLR extracellular domain. Based on the model, we present a mechanistic justification behind the observed detrimental effect of the mutation on LDL-C levels.
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Affiliation(s)
- Khalid Al-Rasadi
- Department of Clinical Biochemistry, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman Familial Hypercholesterolemia Study Group, Oman Society of Lipid and Atherosclerosis (OSLA), Sultan Qaboos University, Muscat, Oman
| | - Khalid Al-Waili
- Department of Clinical Biochemistry, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman Familial Hypercholesterolemia Study Group, Oman Society of Lipid and Atherosclerosis (OSLA), Sultan Qaboos University, Muscat, Oman
| | - Ward Al-Muna Al-Zidi
- Department of Clinical Biochemistry, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Abdul Rahim Al-Abri
- Department of Clinical Biochemistry, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman Familial Hypercholesterolemia Study Group, Oman Society of Lipid and Atherosclerosis (OSLA), Sultan Qaboos University, Muscat, Oman
| | - Ali T Al-Hinai
- Department of Medicine, College of Medicine & Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Hilal Ali Al-Sabti
- Department of Surgery, Cardiothoracic Surgery Division, Sultan Qaboos University Hospital, Muscat, Oman
| | - Sheikha Al-Tobi
- Department of Clinical Biochemistry, Medical Laboratory Science program, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Ibrahim Al-Zakwani
- Department of Pharmacology & Clinical Pharmacy, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Fahad Al-Zadjali
- Department of Clinical Biochemistry, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Khamis Al-Hashmi
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Yajnavalka Banerjee
- Department of Clinical Biochemistry, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman Familial Hypercholesterolemia Study Group, Oman Society of Lipid and Atherosclerosis (OSLA), Sultan Qaboos University, Muscat, Oman
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19
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Grove ML, Yu B, Cochran BJ, Haritunians T, Bis JC, Taylor KD, Hansen M, Borecki IB, Cupples LA, Fornage M, Gudnason V, Harris TB, Kathiresan S, Kraaij R, Launer LJ, Levy D, Liu Y, Mosley T, Peloso GM, Psaty BM, Rich SS, Rivadeneira F, Siscovick DS, Smith AV, Uitterlinden A, van Duijn CM, Wilson JG, O'Donnell CJ, Rotter JI, Boerwinkle E. Best practices and joint calling of the HumanExome BeadChip: the CHARGE Consortium. PLoS One 2013; 8:e68095. [PMID: 23874508 PMCID: PMC3709915 DOI: 10.1371/journal.pone.0068095] [Citation(s) in RCA: 204] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 05/25/2013] [Indexed: 12/25/2022] Open
Abstract
Genotyping arrays are a cost effective approach when typing previously-identified genetic polymorphisms in large numbers of samples. One limitation of genotyping arrays with rare variants (e.g., minor allele frequency [MAF] <0.01) is the difficulty that automated clustering algorithms have to accurately detect and assign genotype calls. Combining intensity data from large numbers of samples may increase the ability to accurately call the genotypes of rare variants. Approximately 62,000 ethnically diverse samples from eleven Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium cohorts were genotyped with the Illumina HumanExome BeadChip across seven genotyping centers. The raw data files for the samples were assembled into a single project for joint calling. To assess the quality of the joint calling, concordance of genotypes in a subset of individuals having both exome chip and exome sequence data was analyzed. After exclusion of low performing SNPs on the exome chip and non-overlap of SNPs derived from sequence data, genotypes of 185,119 variants (11,356 were monomorphic) were compared in 530 individuals that had whole exome sequence data. A total of 98,113,070 pairs of genotypes were tested and 99.77% were concordant, 0.14% had missing data, and 0.09% were discordant. We report that joint calling allows the ability to accurately genotype rare variation using array technology when large sample sizes are available and best practices are followed. The cluster file from this experiment is available at www.chargeconsortium.com/main/exomechip.
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Affiliation(s)
- Megan L Grove
- School of Public Health, Human Genetics Center, The University of Texas Health Science Center at Houston, Houston, Texas, USA.
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20
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Guardamagna O, Cagliero P, Abello F. Management of Inherited Atherogenic Dyslipidemias in Children. Ther Apher Dial 2012; 17:150-61. [DOI: 10.1111/j.1744-9987.2012.01146.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Tichý L, Freiberger T, Zapletalová P, Soška V, Ravčuková B, Fajkusová L. The molecular basis of familial hypercholesterolemia in the Czech Republic: spectrum of LDLR mutations and genotype-phenotype correlations. Atherosclerosis 2012; 223:401-8. [PMID: 22698793 DOI: 10.1016/j.atherosclerosis.2012.05.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 05/10/2012] [Accepted: 05/11/2012] [Indexed: 11/25/2022]
Abstract
BACKGROUND Familial hypercholesterolemia (FH), a major risk for coronary heart disease, is predominantly associated with mutations in the genes encoding the low-density lipoprotein receptor (LDLR) and its ligand apolipoprotein B (APOB). RESULTS In this study, we characterize the spectrum of mutations causing FH in 2239 Czech probands suspected to have FH. In this set, we found 265 patients (11.8%) with the APOB mutation p.(Arg3527Gln) and 535 patients (23.9%) with a LDLR mutation. In 535 probands carrying the LDLR mutation, 127 unique allelic variants were detected: 70.1% of these variants were DNA substitutions, 16.5% small DNA rearrangements, and 13.4% large DNA rearrangements. Fifty five variants were novel, not described in other FH populations. For lipid profile analyses, FH probands were divided into groups [patients with the LDLR mutation (LDLR+), with the APOB mutation (APOB+), and without a detected mutation (LDLR-/APOB-)], and each group into subgroups according to gender. The statistical analysis of lipid profiles was performed in 1722 probands adjusted for age in which biochemical data were obtained without FH treatment (480 LDLR+ patients, 222 APOB+ patients, and 1020 LDLR-/APOB- patients). Significant gradients in i) total cholesterol (LDLR+ patients > APOB+ patients = LDLR-/APOB- patients) ii) LDL cholesterol (LDLR+ patients > APOB+ patients = LDLR-/APOB- patients in men and LDLR+patients > APOB+ patients >LDLR-/APOB- patients in women), iii) triglycerides (LDLR-/APOB- patients > LDLR+ patients > APOB+ patients), and iv) HDL cholesterol (APOB+ patients > LDLR-/APOB- patients = LDLR+ patients) were shown. CONCLUSION Our study presents a large set of Czech patients with FH diagnosis in which DNA diagnostics was performed and which allowed statistical analysis of clinical and biochemical data.
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Affiliation(s)
- Lukáš Tichý
- Centre of Molecular Biology and Gene Therapy, University Hospital Brno, Brno, Czech Republic
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Liyanage KE, Burnett JR, Hooper AJ, van Bockxmeer FM. Familial hypercholesterolemia: epidemiology, Neolithic origins and modern geographic distribution. Crit Rev Clin Lab Sci 2011; 48:1-18. [DOI: 10.3109/10408363.2011.565585] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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23
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Miltiadous G, Xenophontos S, Bairaktari E, Ganotakis M, Cariolou M, Elisaf M. Genetic and environmental factors affecting the response to statin therapy in patients with molecularly defined familial hypercholesterolaemia. Pharmacogenet Genomics 2005; 15:219-25. [PMID: 15864114 DOI: 10.1097/01213011-200504000-00005] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Familial hypercholesterolaemia (FH) is the most common inherited metabolic disease characterized by elevated serum levels of low-density lipoprotein cholesterol (LDL-C) and ischaemic heart disease early in life. Early diagnosis and treatment are essential to prevent premature atherosclerosis in FH patients. The aim of our study was the evaluation of the effects of genetic [class of the LDL receptor (LDLR) gene mutation, apolipoprotein (apo)E, apoA-IV and cholesterol ester transfer protein gene polymorphisms] and environmental factors (age, sex, smoking habit and body mass index) on the lipid-lowering response to statin therapy in patients with molecularly defined FH. Atorvastatin 20 mg/day was prescribed in 49 patients with heterozygous FH. The lipid profile was examined before and after 12 weeks of therapy. Statin therapy resulted in a decrease of 37% and 36% in LDL-C and apoB levels, respectively. The study population was then divided into 2 groups according to the class of the LDLR mutation [patients sharing a class V mutation (the G1775A mutation, n=21) and patients sharing class II mutations (the G1646A and the C858A mutations, n=28)]. In both groups, the percentage decrement in LDL-C and apoB levels were correlated with the initial LDL-C and apoB levels, respectively. The class of the LDLR mutation affected the LDL-C and apoB-lowering response of heterozygous FH patients to statin therapy. In detail, heterozygotes sharing a class V mutation of the LDLR showed a higher percentage decrement in LDL-C and apoB levels after atorvastatin administration compared to patients sharing class II mutations (49+/-9% versus 34+/-9%, P=0.001 for LDL-C and 42+/-16% versus 35+/-20%, P=0.001 for apoB). The influence of the classes of the LDLR gene mutations on the change of LDL-C and apoB levels to atorvastatin was still significant in a multivariate analysis. None of the other genetic and environmental factors studied affected the lipid-lowering response to atorvastatin therapy in patients with heterozygous FH in a multivariate analysis. Our data indicate that the class of the LDLR gene mutation affects the LDL-C and apoB-lowering response of heterozygous FH patients to statin therapy. Specifically, patients with a class V mutation exhibit higher percentage decrease in LDL-C and apoB levels after statin therapy compared to patients sharing class II mutations.
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Affiliation(s)
- George Miltiadous
- Department of Internal Medicine, Medical School, University of Ioannina, Ioannina, Greece
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Muller PY, Miserez AR. Large heterogeneity of mutations in the gene encoding the low-density lipoprotein receptor in subjects with familial hypercholesterolaemia. ATHEROSCLEROSIS SUPP 2004; 5:1-5. [PMID: 15556092 DOI: 10.1016/j.atherosclerosissup.2004.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular genetic testing for presymptomatic identification of subjects affected by familial hypercholesterolaemia (FH) is difficult due to the heterogeneity of the mutations in the gene encoding the low-density lipoprotein receptor (LDLR) in most populations. This investigation presents a detailed analysis of comparable, country-specific prevalence data of LDLR mutations in subjects with clinically defined FH and assesses the heterogeneous mutation diversity observed in most geographic regions.
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Affiliation(s)
- Patrick Y Muller
- Department of Clinical-Biological Sciences, Cardiovascular Genetics, Institute of Biochemistry and Genetics, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland
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25
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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.
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Affiliation(s)
- George V Z Dedoussis
- Department of Science Dietetics-Nutrition, Harokopio University of Athens, Athens, Greece
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26
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Thorsson B, Sigurdsson G, Gudnason V. Systematic family screening for familial hypercholesterolemia in Iceland. Arterioscler Thromb Vasc Biol 2003; 23:335-8. [PMID: 12588780 DOI: 10.1161/01.atv.0000051874.51341.8c] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE This study compares a novel approach using systematic family screening for patients in Iceland who have familial hypercholesterolemia (FH) with conventional proband screening and assesses the sensitivity and specificity of diagnosing FH by cholesterol measurements compared with mutational testing of family members. METHODS AND RESULTS Probands with the I4T+2C mutation were traced to common ancestors. A downtracing of each family lineage was performed back to the oldest living offspring (key individuals); these individuals were recruited for cholesterol measurement and mutation testing. The sensitivity and specificity of cholesterol measurements was assessed against mutational analysis. Eleven probands clustered into 4 families. There were 364 key individuals identified among their descendants. Eighty-four percent responded, and 11% were positive for the mutation. There were 78 offspring of the positive key individuals, and 40 of those were carriers. Compared with use of the conventional first-degree relative approach, an additional 19% of FH individuals, including key individuals and their descendants, were identified. As diagnostic criteria, cholesterol measurements in the families had 95% specificity and 94% sensitivity. CONCLUSIONS Tracing FH probands to common ancestors and screening the oldest offspring in each family lineage adds considerably to the conventional method of FH screening (testing first-degree relatives). This may have relevance in other founder populations.
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Affiliation(s)
- Bolli Thorsson
- Icelandic Heart Association Research Institute, Kopavogur, Iceland
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27
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Orr� S, Pintor S, Loizedda A, Giuressi E, Murru R, Casula M, Carcassi C, Deiana L, Contu L. Familial hypercholesterolemia study in Sardinia using 6 LDLR polymorphic markers based on PCR. ACTA ACUST UNITED AC 2000. [DOI: 10.1002/(sici)1096-8628(20000306)91:1<34::aid-ajmg6>3.0.co;2-t] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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28
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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.
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Affiliation(s)
- H K Jensen
- Department of Medicine and Cardiology, Aarhus Amtssygehus University Hospital, Aarhus C, Denmark.
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29
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von Kodolitsch Y, Pyeritz RE, Rogan PK. Splice-site mutations in atherosclerosis candidate genes: relating individual information to phenotype. Circulation 1999; 100:693-9. [PMID: 10449689 DOI: 10.1161/01.cir.100.7.693] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Nucleotide variants in several genes for lipid and methionine metabolism influence the risk of premature atherosclerosis. Ten percent of single nucleotide substitutions in these genes involve mRNA splice sites. The effects of some of these changes on splicing and on phenotypic severity are not inherently obvious. METHODS AND RESULTS Using an information theory-based model, we measured the individual information content (R(i), in bits) of splice sites adjacent to 289 mutations (including 31 splice-site mutations) in the atherosclerosis candidate genes APOAII, APOB, APOCII, APOE, CBS, CETP, LCAT, LIPA, LDLR, and LPL. The predictions of information analysis were then corroborated by published mRNA analyses. The R(i) values of mutant sites were consistent with either complete (n=17) or partial (n=8) inactivation of these sites. Seven mutations were predicted to activate cryptic splice sites. Predicted inactive mutant sites were associated with either "average" or "severe" dyslipidemia and commensurate reductions in protein levels or activity, whereas mutations expected to exhibit residual splicing had average or "mild" effects on lipid and protein expression. CONCLUSIONS Information analysis of splice-junction variants in atherosclerosis candidate genes distinguishes inactive from leaky splice sites and identifies activated cryptic sites. Predicted changes in splicing were related to phenotypic severity.
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Affiliation(s)
- Y von Kodolitsch
- Department of Cardiology, University Hospital Eppendorf, Hamburg, Germany
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30
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Abstract
Recent research has focused on the rapid detection of new LDL receptor gene variants and large scale screening for known mutations. Whether the nature of the mutation in the LDL receptor gene in familial hypercholesterolaemia determines clinical variability has been examined, as well as the potential value of detecting mutation carriers for clinical practice. There is also evidence that some patients with clinical familial hypercholesterolaemia do not have detectable defects in the LDL receptor or apolipoprotein B.
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Affiliation(s)
- A K Soutar
- MRC Lipoprotein Team, Imperial College School of Medicine, Hammersmith Hospital, London, UK.
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Descamps O, Hondekijn JC, Van Acker P, Deslypere JP, Heller FR. High prevalence of a novel mutation in the exon 4 of the low-density lipoprotein receptor gene causing familial hypercholesterolemia in Belgium. Clin Genet 1997; 51:303-8. [PMID: 9212177 DOI: 10.1111/j.1399-0004.1997.tb02478.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In a cohort of 70 unrelated patients living in Southern Belgium with autosomal dominantly inherited hypercholesterolemia, 11 had a hitherto undescribed mutation in exon 4. It consisted in a C-->A mutation at nucleotide 366, resulting in a stop codon at residue Cys122. This C122X mutation is expected to cause a class I receptor defect. The biochemical and clinical data collected from the patients carrying the mutation were consistent with a severe form of familial hypercholesterolemia (FH). Some differences between generations were noted. Amongst the C122X carriers, those born after 1926 had cardiovascular complications earlier than those born before 1926. This raises the possibility that changes in environmental factors during the course of the century have had an unfavorable impact on the prognosis of the disease. The mutation was found in 16% of the suspected FH patients and less frequently (less than 3% of suspected FH) in Northern Belgium. The haplotype of the chromosomes carrying the mutation was the same in all C122X families, but extensive genealogical studies failed to reveal a common ancestor. We conclude that C122X is an old and common cause of FH in Belgium. Screening for this mutation may be useful in the diagnosis of FH in Belgium.
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Affiliation(s)
- O Descamps
- Groupe d'Etude du Métabolisme Tumoral and Department of Internal Medicine, Hopital de Jolimont, Haine Saint-Paul, Belgium.
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