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Alieva A, Di Costanzo A, Gazzotti M, Reutova O, Usova E, Bakaleiko V, Arca M, D'Erasmo L, Pellegatta F, Galimberti F, Olmastroni E, Catapano AL, Casula M. Genetic heterogeneity of familial hypercholesterolaemia in two populations from two different countries. Eur J Intern Med 2024; 123:65-71. [PMID: 38245461 DOI: 10.1016/j.ejim.2024.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/11/2024] [Accepted: 01/15/2024] [Indexed: 01/22/2024]
Abstract
BACKGROUND Familial hypercholesterolemia (FH) is a genetically determined monogenic disorder of predominantly autosomal dominant inheritance. A number of studies on differences in the genetic profile of patients with FH have demonstrated the importance of a more substantive evaluation of genetic features. The aim of this study was to evaluate the genetic profile of patients with clinical FH among Italian and Russian patients. METHODS We included 144 Italian and 79 Russian FH patients; clinical diagnosis was based on the same criteria. Patients were divided in: positive to genetic test (one causative variant), inconclusive (only variants of uncertain clinical significance [VUS]), and negative (with likely benign/benign variants, heterozygous variants in LDLRAP1 gene, or without causative variants). RESULTS The genetic test was positive in 76.4 % of the Italian patients and in 49.4 % of the Russian patients. The presence of VUS alone was detected in 7.6 % and in 19.0 % (p < 0.001), respectively. Among patients with positive genetic diagnosis, pre-treatment LDL-C levels were higher in the Russian cohort (353.5 ± 111.3 vs. 302.7 ± 52.1 mg/dL, p = 0.009), as well as the percentage of treated patients (53.8 % vs. 14.5 %, p < 0.001) and the prevalence of premature coronary heart disease (12.8 % vs. 3.6 %, p = 0.039). Among patients carrying only VUS, mean pre-treatment LDL-C levels were similar between the cohorts (299.5 ± 68.1 vs. 295.3 ± 46.8 mg/dL, p = 0.863). Among pathogenic/likely pathogenic variants and VUS, only 5 % and 4 % was shared between the two cohorts, respectively. CONCLUSION The genetic background of patients clinically diagnosed with FH in two different countries is characterized by high variability.
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Affiliation(s)
- Asiiat Alieva
- Almazov National Medical Research Centre, Saint Petersburg, Russia.
| | - Alessia Di Costanzo
- Department of Translational and Precision Medicine, Sapienza University of Rome, Rome, Italy
| | | | - Olga Reutova
- Almazov National Medical Research Centre, Saint Petersburg, Russia
| | - Elena Usova
- Almazov National Medical Research Centre, Saint Petersburg, Russia
| | | | - Marcello Arca
- Department of Translational and Precision Medicine, Sapienza University of Rome, Rome, Italy
| | - Laura D'Erasmo
- Department of Translational and Precision Medicine, Sapienza University of Rome, Rome, Italy
| | | | | | - Elena Olmastroni
- IRCCS MultiMedica, Sesto San Giovanni, Milan, Italy; Epidemiology and Preventive Pharmacology Service (SEFAP), Department of Pharmacological and Biomolecular Sciences (DisFeB), University of Milan, Milan, Italy
| | - Alberico L Catapano
- IRCCS MultiMedica, Sesto San Giovanni, Milan, Italy; Epidemiology and Preventive Pharmacology Service (SEFAP), Department of Pharmacological and Biomolecular Sciences (DisFeB), University of Milan, Milan, Italy
| | - Manuela Casula
- IRCCS MultiMedica, Sesto San Giovanni, Milan, Italy; Epidemiology and Preventive Pharmacology Service (SEFAP), Department of Pharmacological and Biomolecular Sciences (DisFeB), University of Milan, Milan, Italy
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Dharmayat KI, Vallejo-Vaz AJ, Stevens CA, Brandts JM, Lyons AR, Groselj U, Abifadel M, Aguilar-Salinas CA, Alhabib K, Alkhnifsawi M, Almahmeed W, Alnouri F, Alonso R, Al-Rasadi K, Ashavaid TF, Banach M, Béliard S, Binder C, Bourbon M, Chlebus K, Corral P, Cruz D, Descamps OS, Drogari E, Durst R, Ezhov MV, Genest J, Harada-Shiba M, Holven KB, Humphries SE, Khovidhunkit W, Lalic K, Laufs U, Liberopoulos E, Roeters van Lennep J, Lima-Martinez MM, Lin J, Maher V, März W, Miserez AR, Mitchenko O, Nawawi H, Panayiotou AG, Paragh G, Postadzhiyan A, Reda A, Reiner Ž, Reyes X, Sadiq F, Sahebkar A, Schunkert H, Shek AB, Stroes E, Su TC, Subramaniam T, Susekov A, Vázquez Cárdenas A, Huong Truong T, Tselepis AD, Vohnout B, Wang L, Yamashita S, Al-Sarraf A, Al-Sayed N, Davletov K, Dwiputra B, Gaita D, Kayikcioglu M, Latkovskis G, Marais AD, Thushara Matthias A, Mirrakhimov E, Nordestgaard BG, Petrulioniene Z, Pojskic B, Sadoh W, Tilney M, Tomlinson B, Tybjærg-Hansen A, Viigimaa M, Catapano AL, Freiberger T, Hovingh GK, Mata P, Soran H, Raal F, Watts GF, Schreier L, Bañares V, Greber-Platzer S, Baumgartner-Kaut M, de Gier C, Dieplinger H, Höllerl F, Innerhofer R, Karall D, Lischka J, Ludvik B, Mäser M, Scholl-Bürgi S, Thajer A, Toplak H, Demeure F, Mertens A, Balligand JL, Stephenne X, Sokal E, Petrov I, Goudev A, Nikolov F, Tisheva S, Yotov Y, Tzvetkov I, Hegele RA, Gaudet D, Brunham L, Ruel I, McCrindle B, Cuevas A, Perica D, Symeonides P, Trogkanis E, Kostis A, Ioannou A, Mouzarou A, Georgiou A, Stylianou A, Miltiadous G, Iacovides P, Deltas C, Vrablik M, Urbanova Z, Jesina P, Tichy L, Hyanek J, Dvorakova J, Cepova J, Sykora J, Buresova K, Pipek M, Pistkova E, Bartkova I, S|ulakova A, Toukalkova L, Spenerova M, Maly J, Benn M, Bendary A, Elbahry A, Ferrières J, Ferrieres D, Peretti N, Bruckert E, Gallo A, Valero R, Mourre F, Aouchiche K, Reynaud R, Tounian P, Lemale J, Boccara F, Moulin P, Charrières S, Di Filippo M, Cariou B, Paillard F, Dourmap C, Pradignac A, Verges B, Simoneau I, Farnier M, Cottin Y, Yelnik C, Hankard R, Schiele F, Durlach V, Sultan A, Carrié A, Rabès JP, Sanin V, Schmieder RS, Ates S, Rizos CV, Skoumas I, Tziomalos K, Rallidis L, Kotsis V, Doumas M, Skalidis E, Kolovou G, Kolovou V, Garoufi A, Koutagiar I, Polychronopoulos G, Kiouri E, Antza C, Zacharis E, Attilakos A, Sfikas G, Koumaras C, Anagnostis P, Anastasiou G, Liamis G, Adamidis PS, Milionis H, Lambadiari V, Stabouli S, Filippatos T, Mollaki V, Tsaroumi A, Lamari F, Proyias P, Harangi M, Reddy LL, Shah SAV, Ponde CK, Dalal JJ, Sawhney JP, Verma IC, Hosseini S, Jamialahmadi T, Alareedh M, Shaghee F, Rhadi SH, Abduljalal M, Alfil S, Kareem H, Cohen H, Leitersdorf E, Schurr D, Shpitzen S, Arca M, Averna M, Bertolini S, Calandra S, Tarugi P, Casula M, Galimberti F, Gazzotti M, Olmastroni E, Sarzani R, Ferri C, Repetti E, Giorgino F, Suppressa P, Bossi AC, Borghi C, Muntoni S, Cipollone F, Scicali R, Pujia A, Passaro A, Berteotti M, Pecchioli V, Pisciotta L, Mandraffino G, Pellegatta F, Mombelli G, Branchi A, Fiorenza AM, Pederiva C, Werba JP, Parati G, Nascimbeni F, Iughetti L, Fortunato G, Cavallaro R, Iannuzzo G, Calabrò P, Cefalù AB, Capra ME, Zambon A, Pirro M, Sbrana F, Trenti C, Minicocci I, Federici M, Del Ben M, Buonuomo PS, Moffa S, Pipolo A, Citroni N, Guardamagna O, Lia S, Benso A, Biolo GB, Maroni L, Lupi A, Bonanni L, Rinaldi E, Zenti MG, Masuda D, Mahfouz L, Jambart S, Ayoub C, Ghaleb Y, Kasim NAM, Nor NSM, Al-Khateeb A, Kadir SHSA, Chua YA, Razman AZ, Nazli SA, Ranai NM, Latif AZA, Torres MTM, Mehta R, Martagon AJ, Ramirez GAG, Antonio-Villa NE, Vargas-Vazquez A, Elias-Lopez D, Retana GG, Encinas BR, Macıas JJC, Zazueta AR, Alvarado RM, Portano JDM, Lopez HA, Sauque-Reyna L, Gomez Herrera LG, Simental Mendia LE, Aguilar HG, Cooremans ER, Aparicio BP, Zubieta VM, Gonzalez PAC, Ferreira-Hermosillo A, Portilla NC, Dominguez GJ, Garcia AYR, Arriaga Cazares HE, Gonzalez Gonzalez JR, Mendez Valencia CV, Padilla Padilla FG, Prado RM, De los Rios Ibarra MO, Arjona Villica~na RD, Acevedo Rivera KJ, Carrera RA, Alvarez JA, Amezcua Martinez JC, Barrera Bustillo MDLR, Vargas GC, Chacon RC, Figueroa Andrade MH, Ortega AF, Alcala HG, Garcia de Leon LE, Guzman BG, Gardu~no Garcia JJ, Garnica Cuellar JC, Gomez Cruz JR, Garcia AH, Holguin Almada JR, Herrera UJ, Sobrevilla FL, Rodriguez EM, Sibaja CM, Medrano Rodriguez AB, Morales Oyervides JC, Perez Vazquez DI, Reyes Rodriguez EA, Osorio MLR, Saucedo JR, Tamayo MT, Valdez Talavera LA, Vera Arroyo LE, Zepeda Carrillo EA, Galema-Boers A, Weigman A, Bogsrud MP, Malik M, Shah S, Khan SA, Rana MA, Batool H, Starostecka E, Konopka A, Lewek J, Bielecka-Dąbrowa A, Gach A, Jóźwiak J, Pajkowski M, Romanowska-Kocejko M, Żarczyńska-Buchowiecka M, Hellmann M, Chmara M, Wasąg B, Parczewska A, Gilis-Malinowska N, Borowiec-Wolna J, Stróżyk A, Michalska-Grzonkowska A, Chlebus I, Kleinschmidt M, Wojtecka A, Zdrojewski T, Myśliwiec M, Hennig M, Medeiros AM, Alves AC, Almeida AF, Lopes A, Guerra A, Bilhoto C, Simões F, Silva F, Lobarinhas G, Gama G, Palma I, Salgado JM, Matos LD, Moura MD, Virtuoso MJ, Tavares M, Ferreira P, Pais P, Garcia P, Coelho R, Ribeiro R, Correia S, Sadykova D, Slastnikova E, Alammari D, Mawlawi HA, Alsahari A, Khudary AA, Alrowaily NL, Rajkovic N, Popovic L, Singh S, Rasulic I, Petakov A, Lalic NM, Peng FK, Vasanwala RF, Venkatesh SA, Raslova K, Fabryova L, Nociar J, Šaligova J, Potočňáková L, Kozárová M, Varga T, Kadurova M, Debreova M, Novodvorsky P, Gonova K, Klabnik A, Buganova I, Battelino T, Bizjan BJ, Debeljak M, Kovac J, Mlinaric M, Molk N, Sikonja J, Sustar U, Podkrajsek KT, Muñiz-Grijalvo O, Díaz-Díaz JL, de Andrés R, Fuentes-Jiménez F, Blom D, Miserez EB, Shipton JL, Ganokroj P, Futema M, Ramaswami U, Alieva RB, Fozilov KG, Khoshimov SU, Nizamov UI, Abdullaeva GJ, Kan LE, Abdullaev AA, Zakirova DV, Do DL, Nguyen MNT, Kim NT, Le TT, Le HA, Santos R, Ray KK. Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study. Lancet 2024; 403:55-66. [PMID: 38101429 DOI: 10.1016/s0140-6736(23)01842-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/21/2023] [Accepted: 08/29/2023] [Indexed: 12/17/2023]
Abstract
BACKGROUND Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. METHODS For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. FINDINGS Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. INTERPRETATION Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life. FUNDING Pfizer, Amgen, Merck Sharp & Dohme, Sanofi-Aventis, Daiichi Sankyo, and Regeneron.
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Larrea-Sebal A, Jebari-Benslaiman S, Galicia-Garcia U, Jose-Urteaga AS, Uribe KB, Benito-Vicente A, Martín C. Predictive Modeling and Structure Analysis of Genetic Variants in Familial Hypercholesterolemia: Implications for Diagnosis and Protein Interaction Studies. Curr Atheroscler Rep 2023; 25:839-859. [PMID: 37847331 PMCID: PMC10618353 DOI: 10.1007/s11883-023-01154-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2023] [Indexed: 10/18/2023]
Abstract
PURPOSE OF REVIEW Familial hypercholesterolemia (FH) is a hereditary condition characterized by elevated levels of low-density lipoprotein cholesterol (LDL-C), which increases the risk of cardiovascular disease if left untreated. This review aims to discuss the role of bioinformatics tools in evaluating the pathogenicity of missense variants associated with FH. Specifically, it highlights the use of predictive models based on protein sequence, structure, evolutionary conservation, and other relevant features in identifying genetic variants within LDLR, APOB, and PCSK9 genes that contribute to FH. RECENT FINDINGS In recent years, various bioinformatics tools have emerged as valuable resources for analyzing missense variants in FH-related genes. Tools such as REVEL, Varity, and CADD use diverse computational approaches to predict the impact of genetic variants on protein function. These tools consider factors such as sequence conservation, structural alterations, and receptor binding to aid in interpreting the pathogenicity of identified missense variants. While these predictive models offer valuable insights, the accuracy of predictions can vary, especially for proteins with unique characteristics that might not be well represented in the databases used for training. This review emphasizes the significance of utilizing bioinformatics tools for assessing the pathogenicity of FH-associated missense variants. Despite their contributions, a definitive diagnosis of a genetic variant necessitates functional validation through in vitro characterization or cascade screening. This step ensures the precise identification of FH-related variants, leading to more accurate diagnoses. Integrating genetic data with reliable bioinformatics predictions and functional validation can enhance our understanding of the genetic basis of FH, enabling improved diagnosis, risk stratification, and personalized treatment for affected individuals. The comprehensive approach outlined in this review promises to advance the management of this inherited disorder, potentially leading to better health outcomes for those affected by FH.
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Affiliation(s)
- Asier Larrea-Sebal
- Department of Biochemistry and Molecular Biology, Universidad del País Vasco UPV/EHU, 48080, Bilbao, Spain
- Department of Molecular Biophysics, Biofisika Institute, University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC), 48940, Leioa, Spain
- Fundación Biofisika Bizkaia, 48940, Leioa, Spain
| | - Shifa Jebari-Benslaiman
- Department of Biochemistry and Molecular Biology, Universidad del País Vasco UPV/EHU, 48080, Bilbao, Spain
- Department of Molecular Biophysics, Biofisika Institute, University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC), 48940, Leioa, Spain
| | - Unai Galicia-Garcia
- Department of Biochemistry and Molecular Biology, Universidad del País Vasco UPV/EHU, 48080, Bilbao, Spain
- Department of Molecular Biophysics, Biofisika Institute, University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC), 48940, Leioa, Spain
| | - Ane San Jose-Urteaga
- Department of Biochemistry and Molecular Biology, Universidad del País Vasco UPV/EHU, 48080, Bilbao, Spain
| | - Kepa B Uribe
- Department of Biochemistry and Molecular Biology, Universidad del País Vasco UPV/EHU, 48080, Bilbao, Spain
| | - Asier Benito-Vicente
- Department of Biochemistry and Molecular Biology, Universidad del País Vasco UPV/EHU, 48080, Bilbao, Spain
- Department of Molecular Biophysics, Biofisika Institute, University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC), 48940, Leioa, Spain
| | - César Martín
- Department of Biochemistry and Molecular Biology, Universidad del País Vasco UPV/EHU, 48080, Bilbao, Spain.
- Department of Molecular Biophysics, Biofisika Institute, University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC), 48940, Leioa, Spain.
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Albuquerque J, Medeiros AM, Alves AC, Jannes CE, Mancina RM, Pavanello C, Chora JR, Mombelli G, Calabresi L, Pereira ADC, Krieger JE, Romeo S, Bourbon M, Antunes M. Generation and validation of a classification model to diagnose familial hypercholesterolaemia in adults. Atherosclerosis 2023; 383:117314. [PMID: 37813054 DOI: 10.1016/j.atherosclerosis.2023.117314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 09/21/2023] [Accepted: 09/22/2023] [Indexed: 10/11/2023]
Abstract
BACKGROUND AND AIMS The early diagnosis of familial hypercholesterolaemia is associated with a significant reduction in cardiovascular disease (CVD) risk. While the recent use of statistical and machine learning algorithms has shown promising results in comparison with traditional clinical criteria, when applied to screening of potential FH cases in large cohorts, most studies in this field are developed using a single cohort of patients, which may hamper the application of such algorithms to other populations. In the current study, a logistic regression (LR) based algorithm was developed combining observations from three different national FH cohorts, from Portugal, Brazil and Sweden. Independent samples from these cohorts were then used to test the model, as well as an external dataset from Italy. METHODS The area under the receiver operating characteristics (AUROC) and precision-recall (AUPRC) curves was used to assess the discriminatory ability among the different samples. Comparisons between the LR model and Dutch Lipid Clinic Network (DLCN) clinical criteria were performed by means of McNemar tests, and by the calculation of several operating characteristics. RESULTS AUROC and AUPRC values were generally higher for all testing sets when compared to the training set. Compared with DLCN criteria, a significantly higher number of correctly classified observations were identified for the Brazilian (p < 0.01), Swedish (p < 0.01), and Italian testing sets (p < 0.01). Higher accuracy (Acc), G mean and F1 score values were also observed for all testing sets. CONCLUSIONS Compared to DLCN criteria, the LR model revealed improved ability to correctly classify observations, and was able to retain a similar number of FH cases, with less false positive retention. Generalization of the LR model was very good across all testing samples, suggesting it can be an effective screening tool if applied to different populations.
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Affiliation(s)
- João Albuquerque
- Departamento de Biomedicina, Unidade de Bioquímica, Faculdade de Medicina, Universidade do Porto, 4200-319, Porto, Portugal; Centro de Estatística e Aplicações, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal; Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016, Lisboa, Portugal.
| | - Ana Margarida Medeiros
- Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016, Lisboa, Portugal; Instituto de Biossistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Ana Catarina Alves
- Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016, Lisboa, Portugal; Instituto de Biossistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Cinthia Elim Jannes
- Laboratório de Genética e Cardiologia Molecular, Instituto do Coração, São Paulo, Brazil
| | - Rosellina M Mancina
- Sahlgrenska Academy, Institute of Medicine, Department of Molecular and Clinical Medicine, Wallenberg Laboratory, University of Gothenburg, Sweden
| | - Chiara Pavanello
- Centro Grossi Paoletti, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milano, Italy
| | - Joana Rita Chora
- Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016, Lisboa, Portugal; Instituto de Biossistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Giuliana Mombelli
- Centro Dislipidemie, ASST Grande Ospedale Metropolitano Niguarda, 20162, Milano, Italy
| | - Laura Calabresi
- Centro Grossi Paoletti, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milano, Italy
| | | | - José Eduardo Krieger
- Laboratório de Genética e Cardiologia Molecular, Instituto do Coração, São Paulo, Brazil
| | - Stefano Romeo
- Sahlgrenska Academy, Institute of Medicine, Department of Molecular and Clinical Medicine, Wallenberg Laboratory, University of Gothenburg, Sweden; Cardiology Department, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Clinical and Surgical Sciences, Nutrition Unit, University Magna Graecia, Catanzaro, Italy
| | - Mafalda Bourbon
- Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016, Lisboa, Portugal; Instituto de Biossistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Marília Antunes
- Centro de Estatística e Aplicações, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal; Departamento de Estatística e Investigação Operacional, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
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Albuquerque J, Medeiros AM, Alves AC, Bourbon M, Antunes M. Comparative study on the performance of different classification algorithms, combined with pre- and post-processing techniques to handle imbalanced data, in the diagnosis of adult patients with familial hypercholesterolemia. PLoS One 2022; 17:e0269713. [PMID: 35749402 PMCID: PMC9231719 DOI: 10.1371/journal.pone.0269713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 05/26/2022] [Indexed: 11/27/2022] Open
Abstract
Familial Hypercholesterolemia (FH) is an inherited disorder of cholesterol metabolism. Current criteria for FH diagnosis, like Simon Broome (SB) criteria, lead to high false positive rates. The aim of this work was to explore alternative classification procedures for FH diagnosis, based on different biological and biochemical indicators. For this purpose, logistic regression (LR), naive Bayes classifier (NB), random forest (RF) and extreme gradient boosting (XGB) algorithms were combined with Synthetic Minority Oversampling Technique (SMOTE), or threshold adjustment by maximizing Youden index (YI), and compared. Data was tested through a 10 × 10 repeated k-fold cross validation design. The LR model presented an overall better performance, as assessed by the areas under the receiver operating characteristics (AUROC) and precision-recall (AUPRC) curves, and several operating characteristics (OC), regardless of the strategy to cope with class imbalance. When adopting either data processing technique, significantly higher accuracy (Acc), G-mean and F1 score values were found for all classification algorithms, compared to SB criteria (p < 0.01), revealing a more balanced predictive ability for both classes, and higher effectiveness in classifying FH patients. Adjustment of the cut-off values through pre or post-processing methods revealed a considerable gain in sensitivity (Sens) values (p < 0.01). Although the performance of pre and post-processing strategies was similar, SMOTE does not cause model’s parameters to loose interpretability. These results suggest a LR model combined with SMOTE can be an optimal approach to be used as a widespread screening tool.
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Affiliation(s)
- João Albuquerque
- Departamento de Biomedicina, Unidade de Bioquímica, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
- Centro de Estatística e Aplicações, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
- Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal
- * E-mail:
| | - Ana Margarida Medeiros
- Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal
- Instituto de Biossistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Ana Catarina Alves
- Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal
- Instituto de Biossistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Mafalda Bourbon
- Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal
- Instituto de Biossistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Marília Antunes
- Centro de Estatística e Aplicações, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
- Departamento de Estatística e Investigação Operacional, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
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6
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Graça R, Alves AC, Zimon M, Pepperkok R, Bourbon M. Functional profiling of LDLR variants: important evidence for variant classification. J Clin Lipidol 2022; 16:516-524. [DOI: 10.1016/j.jacl.2022.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 04/20/2022] [Accepted: 04/25/2022] [Indexed: 10/18/2022]
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7
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Albuquerque J, Medeiros AM, Alves AC, Bourbon M, Antunes M. Performance comparison of different classification algorithms applied to the diagnosis of familial hypercholesterolemia in paediatric subjects. Sci Rep 2022; 12:1164. [PMID: 35064162 PMCID: PMC8782861 DOI: 10.1038/s41598-022-05063-8] [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] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 12/28/2021] [Indexed: 12/03/2022] Open
Abstract
Familial Hypercholesterolemia (FH) is an inherited disorder of lipid metabolism, characterized by increased low density lipoprotein cholesterol (LDLc) levels. The main purpose of the current work was to explore alternative classification methods to traditional clinical criteria for FH diagnosis, based on several biochemical and biological indicators. Logistic regression (LR), decision tree (DT), random forest (RF) and naive Bayes (NB) algorithms were developed for this purpose, and thresholds were optimized by maximization of Youden index (YI). All models presented similar accuracy (Acc), specificity (Spec) and positive predictive values (PPV). Sensitivity (Sens) and G-mean values were significantly higher in LR and RF models, compared to the DT. When compared to Simon Broome (SB) biochemical criteria for FH diagnosis, all models presented significantly higher Acc, Spec and G-mean values (p < 0.01), and lower negative predictive value (NPV, p < 0.05). Moreover, LR and RF models presented comparable Sens values. Adjustment of the cut-off point by maximizing YI significantly increased Sens values, with no significant loss in Acc. The obtained results suggest such classification algorithms can be a viable alternative to be used as a widespread screening method. An online application has been developed to assess the performance of the LR model in a wider population.
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Affiliation(s)
- João Albuquerque
- Departamento de Biomedicina, Unidade de Bioquímica, Faculdade de Medicina, Universidade do Porto, 4200-319, Porto, Portugal.
- Centro de Estatística e Aplicações, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.
| | - Ana Margarida Medeiros
- Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016, Lisboa, Portugal
- Instituto de Biossistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Ana Catarina Alves
- Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016, Lisboa, Portugal
- Instituto de Biossistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Mafalda Bourbon
- Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016, Lisboa, Portugal
- Instituto de Biossistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Marília Antunes
- Centro de Estatística e Aplicações, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
- Departamento de Estatística e Investigação Operacional, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
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8
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Hu H, Shu T, Ma J, Chen R, Wang J, Wang S, Lin S, Chen X. Two Novel Disease-Causing Mutations in the LDLR of Familial Hypercholesterolemia. Front Genet 2022; 12:762587. [PMID: 34970301 PMCID: PMC8712701 DOI: 10.3389/fgene.2021.762587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 11/10/2021] [Indexed: 12/03/2022] Open
Abstract
As an autosomal dominant disorder, familial hypercholesterolemia (FH) is mainly caused by pathogenic mutations in lipid metabolism-related genes. The aim of this study is to investigate the genetic mutations in FH patients and verify their pathogenicity. First of all, a pedigree investigation was conducted in one family diagnosed with FH using the Dutch Lipid Clinic Network criteria. The high-throughput sequencing was performed on three family members to explore genetic mutations. The effects of low-density lipoprotein receptor (LDLR) variants on their expression levels and activity were further validated by silico analysis and functional studies. The results revealed that LDLC levels of the proband and his daughter were abnormally elevated. The whole-exome sequencing and Sanger sequencing were used to confirm that there were two LDLR missense mutations (LDLR c.226 G > C, c.1003 G > T) in this family. Bioinformatic analysis (Mutationtaster) indicated that these two mutations might be disease-causing variants. In vitro experiments suggested that LDLR c.226 G > C and c.1003 G > T could attenuate the uptake of Dil-LDL by LDLR. In conclusion, the LDLR c.226 G > C and c.1003 G > T variants might be pathogenic for FH by causing uptake dysfunction of the LDLR.
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Affiliation(s)
- Haochang Hu
- Department of Cardiology, Ningbo First Hospital, Ningbo, China
| | - Tian Shu
- Department of Cardiology, Ningbo First Hospital, Ningbo, China
| | - Jun Ma
- Department of Medical Ultrasonics, First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Ruoyu Chen
- Department of Cardiology, Ningbo First Hospital, Ningbo, China
| | - Jian Wang
- Department of Cardiology, Ningbo First Hospital, Ningbo, China
| | | | - Shaoyi Lin
- Department of Cardiology, Ningbo First Hospital, Ningbo, China
| | - Xiaomin Chen
- Department of Cardiology, Ningbo First Hospital, Ningbo, China
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9
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Hu H, Chen R, Hu Y, Wang J, Lin S, Chen X. The LDLR c.501C>A is a disease-causing variant in familial hypercholesterolemia. Lipids Health Dis 2021; 20:101. [PMID: 34511120 PMCID: PMC8436568 DOI: 10.1186/s12944-021-01536-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/31/2021] [Indexed: 12/23/2022] Open
Abstract
Background As an autosomal dominant disorder, familial hypercholesterolemia (FH) is mainly attributed to disease-causing variants in the low-density lipoprotein receptor (LDLR) gene. The aim of this study was to explore the molecular mechanism of LDLR c.501C>A variant in FH and assess the efficacy of proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitor treatment for FH patients. Methods The whole-exome sequencing was performed on two families to identify disease-causing variants, which were verified by Sanger sequencing. The function of LDLR variant was further explored in HEK293 cells by Western Blot and confocal microscopy. Besides, the therapeutic effects of PCSK9 inhibitor treatment for two probands were assessed for 3 months. Results All members of the two families with the LDLR c.501C>A variant showed high levels of LDLC. The relationship between the clinical phenotype and LDLR variants was confirmed in the current study. Both in silico and in vitro analyses showed that LDLR c.501C>A variant decreased LDLR expression and LDL uptake. PCSK9 inhibitor treatment lowered the lipid level in proband 1 by 24.91%. However, the treatment was ineffective for proband 2. A follow-up study revealed that the PCSK9 inhibitor treatment had low ability of lipid-lowering effect in the patients. Conclusions LDLR c.501C>A variant might be pathogenic for FH. The PCSK9 inhibitor therapy is not a highly effective option for treatment of FH patients with LDLR c.501C>A variant. Supplementary Information The online version contains supplementary material available at 10.1186/s12944-021-01536-3.
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Affiliation(s)
- Haochang Hu
- School of Medicine, Ningbo University, Ningbo, Zhejiang, China.,Department of Cardiology, Ningbo First Hospital, Ningbo, Zhejiang, China
| | - Ruoyu Chen
- School of Medicine, Ningbo University, Ningbo, Zhejiang, China.,Department of Cardiology, Ningbo First Hospital, Ningbo, Zhejiang, China
| | - Yingchu Hu
- Department of Cardiology, Ningbo First Hospital, Ningbo, Zhejiang, China
| | - Jian Wang
- Department of Cardiology, Ningbo First Hospital, Ningbo, Zhejiang, China
| | - Shaoyi Lin
- School of Medicine, Ningbo University, Ningbo, Zhejiang, China. .,Department of Cardiology, Ningbo First Hospital, Ningbo, Zhejiang, China.
| | - Xiaomin Chen
- School of Medicine, Ningbo University, Ningbo, Zhejiang, China. .,Department of Cardiology, Ningbo First Hospital, Ningbo, Zhejiang, China.
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10
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Alves AC, Azevedo S, Benito-Vicente A, Graça R, Galicia-Garcia U, Barros P, Jordan P, Martin C, Bourbon M. LDLR variants functional characterization: Contribution to variant classification. Atherosclerosis 2021; 329:14-21. [PMID: 34167030 DOI: 10.1016/j.atherosclerosis.2021.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/28/2021] [Accepted: 06/02/2021] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND AIMS Familial hypercholesterolaemia (FH) is an autosomal disorder of lipid metabolism presenting with increased cardiovascular risk. LDLR mutations are the cause of disease in 90% of the cases but functional studies have only been performed for about 15% of all LDLR variants. In the Portuguese Familial Hypercholesterolemia Study (PFHS), 142 unique LDLR alterations were identified and 44 (30%) lack functional characterization. The aim of the present work is to increase evidence for variant classification by performing functional characterization of 13 LDLR missense alterations found in Portugal and in 20 other countries. METHODS Different LDLR mutants were generated by site-directed mutagenesis and expressed in CHO-ldlA7 cells lacking endogenous expression of LDLR. To determine the effects of alterations on LDLR function, cell surface expression, binding and uptake of FITC-LDL were assessed by flow cytometry and Western blot. RESULTS Of the 13 variants studied 7 were shown to affect LDLR function - expression, binding or uptake, with rates lower than 60%: p.(Cys184Tyr), p.(Gly207_Ser213del); p.(His211Asp); p.(Asp221Tyr); p.(Glu288Lys); p.(Gly592Glu) and p.(Asp601Val)). The remaining 6 variants do not alter the LDLR function. CONCLUSIONS These studies contributed to an update of these variants classification: from the 9 variants classified as variants of unknown significance, 7 have reached now a final classification and 3 variants have improved classification from likely pathogenic to pathogenic. In Portugal, an additional 55 patients received an FH definite diagnosis thanks to these studies. Since only likely pathogenic and pathogenic variants are clinically actionable, this work shows the importance of functional studies for variant classification.
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Affiliation(s)
- Ana Catarina Alves
- Unidade de I&D, Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal; BioISI - Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Sílvia Azevedo
- Unidade de I&D, Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal
| | - Asier Benito-Vicente
- Biofisika Institute (UPV/EHU, CSIC) and Departamento de Bioquímica y Biología Molecular, Universidad Del País Vasco, Apdo. 644, 48080, Bilbao, Spain
| | - Rafael Graça
- Unidade de I&D, Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal; BioISI - Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Unai Galicia-Garcia
- Biofisika Institute (UPV/EHU, CSIC) and Departamento de Bioquímica y Biología Molecular, Universidad Del País Vasco, Apdo. 644, 48080, Bilbao, Spain; Department of Molecular Biophysics, Fundación Biofísica Bizkaia, 48940, Leioa, Spain
| | - Patrícia Barros
- BioISI - Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal; Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal
| | - Peter Jordan
- BioISI - Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal; Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal
| | - Cesar Martin
- Biofisika Institute (UPV/EHU, CSIC) and Departamento de Bioquímica y Biología Molecular, Universidad Del País Vasco, Apdo. 644, 48080, Bilbao, Spain
| | - Mafalda Bourbon
- Unidade de I&D, Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal; BioISI - Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal.
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11
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Mariano C, Alves AC, Medeiros AM, Chora JR, Antunes M, Futema M, Humphries SE, Bourbon M. The familial hypercholesterolaemia phenotype: Monogenic familial hypercholesterolaemia, polygenic hypercholesterolaemia and other causes. Clin Genet 2021; 97:457-466. [PMID: 31893465 DOI: 10.1111/cge.13697] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/22/2019] [Accepted: 11/29/2019] [Indexed: 12/13/2022]
Abstract
Familial hypercholesterolaemia (FH) is a monogenic disorder characterised by high low-density lipoprotein cholesterol (LDL-C) concentrations and increased cardiovascular risk. However, in clinically defined FH cohorts worldwide, an FH-causing variant is only found in 40%-50% of the cases. The aim of this work was to characterise the genetic cause of the FH phenotype in Portuguese clinical FH patients. Between 1999 and 2017, 731 index patients (311 children and 420 adults) who met the Simon Broome diagnostic criteria had been referred to our laboratory. LDLR, APOB, PCSK9, APOE, LIPA, LDLRAP1, ABCG5/8 genes were analysed by polymerase chain reaction amplification and Sanger sequencing. The 6-SNP LDL-C genetic risk score (GRS) for polygenic hypercholesterolaemia was validated in the Portuguese population and cases with a GRS over the 25th percentile were considered to have a high likelihood of polygenic hypercholesterolaemia. An FH-causing mutation was found in 39% of patients (94% in LDLR, 5% APOB and 1% PCSK9), while at least 29% have polygenic hypercholesterolaemia and 1% have other lipid disorders. A genetic cause for the FH phenotype was found in 503 patients (69%). All known causes of the FH phenotype should be investigated in FH cohorts to ensure accurate diagnosis and appropriate management.
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Affiliation(s)
- Cibelle Mariano
- Cardiovascular Research Group, Research and Development Unit, Department of Health Promotion and Chronic Diseases, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal.,Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, University of Lisbon, Lisbon, Portugal
| | - Ana Catarina Alves
- Cardiovascular Research Group, Research and Development Unit, Department of Health Promotion and Chronic Diseases, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal.,Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, University of Lisbon, Lisbon, Portugal
| | - Ana Margarida Medeiros
- Cardiovascular Research Group, Research and Development Unit, Department of Health Promotion and Chronic Diseases, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal.,Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, University of Lisbon, Lisbon, Portugal
| | - Joana Rita Chora
- Cardiovascular Research Group, Research and Development Unit, Department of Health Promotion and Chronic Diseases, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal.,Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, University of Lisbon, Lisbon, Portugal
| | - Marília Antunes
- Department of Statistics and Operations Research, Faculty of Sciences, University of Lisbon, Lisbon, Portugal.,Centre of Statistics and its Applications - CEAUL, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | - Marta Futema
- Centre for Heart Muscle Disease, Institute of Cardiovascular Sciences, University College London, London, UK
| | - Steve E Humphries
- Centre for Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, UK
| | - Mafalda Bourbon
- Cardiovascular Research Group, Research and Development Unit, Department of Health Promotion and Chronic Diseases, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal.,Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, University of Lisbon, Lisbon, Portugal
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12
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Oommen D, Kizhakkedath P, Jawabri AA, Varghese DS, Ali BR. Proteostasis Regulation in the Endoplasmic Reticulum: An Emerging Theme in the Molecular Pathology and Therapeutic Management of Familial Hypercholesterolemia. Front Genet 2020; 11:570355. [PMID: 33173538 PMCID: PMC7538668 DOI: 10.3389/fgene.2020.570355] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 08/31/2020] [Indexed: 02/05/2023] Open
Abstract
Familial hypercholesterolemia (FH) is an autosomal genetic disease characterized by high serum low-density lipoprotein (LDL) content leading to premature coronary artery disease. The main genetic and molecular causes of FH are mutations in low-density lipoprotein receptor gene (LDLR) resulting in the non-clearance of LDL from the blood by hepatocytes and consequently the formation of plaques. LDLR is synthesized and glycosylated in the endoplasmic reticulum (ER) and then transported to the plasma membrane via Golgi. It is estimated that more than 50% of reported FH-causing mutations in LDLR result in misfolded proteins that are transport-defective and hence retained in ER. ER accumulation of misfolded proteins causes ER-stress and activates unfolded protein response (UPR). UPR aids protein folding, blocks further protein synthesis, and eliminates misfolded proteins via ER-associated degradation (ERAD) to alleviate ER stress. Various studies demonstrated that ER-retained LDLR mutants are subjected to ERAD. Interestingly, chemical chaperones and genetic or pharmacological inhibition of ERAD have been reported to rescue the transport defective mutant LDLR alleles from ERAD and restore their ER-Golgi transport resulting in the expression of functional plasma membrane LDLR. This suggests the possibility of pharmacological modulation of proteostasis in the ER as a therapeutic strategy for FH. In this review, we picture a detailed analysis of UPR and the ERAD processes activated by ER-retained LDLR mutants associated with FH. In addition, we discuss and critically evaluate the potential role of chemical chaperones and ERAD modulators in the therapeutic management of FH.
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Affiliation(s)
- Deepu Oommen
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Praseetha Kizhakkedath
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Aseel A Jawabri
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Divya Saro Varghese
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Bassam R Ali
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.,Department of Pathology, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.,Zayed Center for Health Sciences, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
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13
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Dušková L, Nohelová L, Loja T, Fialová J, Zapletalová P, Réblová K, Tichý L, Freiberger T, Fajkusová L. Low Density Lipoprotein Receptor Variants in the Beta-Propeller Subdomain and Their Functional Impact. Front Genet 2020; 11:691. [PMID: 32695144 PMCID: PMC7339958 DOI: 10.3389/fgene.2020.00691] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 06/05/2020] [Indexed: 12/12/2022] Open
Abstract
Background: Pathogenic variants in the low density lipoprotein receptor gene are associated with familial hypercholesterolemia. Some of these variants can result in incorrect folding of the LDLR protein, which is then accumulated inside the cell and cannot fulfill its function to internalize LDL particles. We analyzed the functional impact of 10 LDLR variants localized in the beta-propeller of epidermal growth factor precursor homology domain. The experimental part of the work was complemented by a structural analysis on the basis of 3D LDLR protein structure. Methods: T-Rex Chinese hamster ovary cells transfected with the human LDLR gene were used for live cell imaging microscopy, flow cytometry, and qRT-PCR analysis. Results: Our results showed that the analyzed LDLR protein variants can be divided into three groups. (1) The variants buried inside the 3D protein structure expressing proteins accumulated in the endoplasmic reticulum (ER) with no or reduced plasma membrane localization and LDL particle internalization, and associated with an increased gene expression of ER-resident chaperones. (2) The variants localized on the surface of 3D protein structure with slightly reduced LDLR plasma membrane localization and LDL particle internalization, and associated with no increased mRNA level of ER-resident chaperones. (3) The variants localized on the surface of the 3D protein structure but expressing proteins with cell responses similar to the group 1. Conclusion: All analyzed LDLR variants have been evaluated as pathogenic but with different effects on protein localization and function, and expression of genes associated with ER stress.
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Affiliation(s)
- Lucie Dušková
- Centre of Molecular Biology and Gene Therapy, University Hospital Brno, Brno, Czechia
| | - Lucie Nohelová
- Centre of Molecular Biology and Gene Therapy, University Hospital Brno, Brno, Czechia
| | - Tomáš Loja
- Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Jana Fialová
- Centre of Molecular Biology and Gene Therapy, University Hospital Brno, Brno, Czechia.,Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Petra Zapletalová
- Centre of Molecular Biology and Gene Therapy, University Hospital Brno, Brno, Czechia
| | - Kamila Réblová
- Centre of Molecular Biology and Gene Therapy, University Hospital Brno, Brno, Czechia.,Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Lukáš Tichý
- Centre of Molecular Biology and Gene Therapy, University Hospital Brno, Brno, Czechia
| | - Tomáš Freiberger
- Centre for Cardiovascular Surgery and Transplantation, Brno, Czechia.,Medical Faculty, Masaryk University, Brno, Czechia
| | - Lenka Fajkusová
- Centre of Molecular Biology and Gene Therapy, University Hospital Brno, Brno, Czechia.,Medical Faculty, Masaryk University, Brno, Czechia.,Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research (NCBR), Faculty of Science, Masaryk University, Brno, Czechia
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14
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Mutation type classification and pathogenicity assignment of sixteen missense variants located in the EGF-precursor homology domain of the LDLR. Sci Rep 2020; 10:1727. [PMID: 32015373 PMCID: PMC6997160 DOI: 10.1038/s41598-020-58734-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 01/21/2020] [Indexed: 12/21/2022] Open
Abstract
The primary genetic cause of familial hypercholesterolemia (FH) is related to mutations in the LDLR gene encoding the Low-density Lipoprotein Receptor. LDLR structure is organized in 5 different domains, including an EGF-precursor homology domain that plays a pivotal role in lipoprotein release and receptor recycling. Mutations in this domain constitute 51.7% of the total missense variants described in LDLR. The aim of the present work was to analyse how clinically significant variants in the EGF-precursor homology domain impact LDLR. The activity of sixteen LDLR variants was functionally characterized by determining LDLR expression by Western blot and LDLR expression, LDL binding capacity and uptake, and LDLR recycling activity by flow cytometry in transfected CHO-ldlA7 cells. Of the analysed variants, we found six non-pathogenic LDLR variants and ten pathogenic variants distributed as follow: three class 3 variants; four class 2 variants; and three class 5 variants. These results can be incorporated into clinical management of patients by helping guide the appropriate level of treatment intensity depending on the extent of loss of LDLR activity. This data can also contribute to cascade-screening for pathogenic FH variants.
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15
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Page MM, Bell DA, Watts GF. Widening the spectrum of genetic testing in familial hypercholesterolaemia: Will it translate into better patient and population outcomes? Clin Genet 2019; 97:543-555. [PMID: 31833051 DOI: 10.1111/cge.13685] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/25/2019] [Accepted: 12/03/2019] [Indexed: 12/14/2022]
Abstract
Familial hypercholesterolaemia (FH) is caused by pathogenic variants in LDLR, APOB or PCSK9. Impaired low-density lipoprotein (LDL) receptor function leads to decreased LDL catabolism and premature atherosclerotic cardiovascular disease (ASCVD). Thousands of LDLR variants are known, but assignation of pathogenicity requires accurate phenotyping, family studies and assessment of LDL receptor function. Precise, genetic diagnosis of FH using targeted next generation sequencing allows for optimal treatment, distinguishing FH from pathogenically distinct disorders requiring different treatment. Polygenic hypercholesterolaemia resulting from an accumulation of LDL cholesterol-raising single nucleotide polymorphisms (SNPs) could also be suspected by this approach. Similarly, ASCVD risk could be estimated by broader sequencing of cholesterol and non-cholesterol-related genes. Both of these areas require further research. The clinical management of FH, focusing on the primary or secondary prevention of ASCVD, has been boosted by PCSK9 inhibitor therapy. The efficacy of PCSK9 inhibitors in homozygous FH may be partly predicted by the LDLR variants. While expanded genetic testing in FH is clinically useful in providing an accurate diagnosis and enabling cost-effective testing of relatives, further research is needed to establish its value in improving clinical outcomes.
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Affiliation(s)
- Michael M Page
- School of Medicine, Faculty of Medicine and Health Sciences, The University of Western Australia, Perth, Australia.,Department of Clinical Biochemistry, Western Diagnostic Pathology, Perth, Australia
| | - Damon A Bell
- School of Medicine, Faculty of Medicine and Health Sciences, The University of Western Australia, Perth, Australia.,Department of Clinical Biochemistry, PathWest Fiona Stanley Hospital and Royal Perth Hospital, Perth, Australia.,Lipid Disorders Clinic, Department of Cardiology, Royal Perth Hospital, Perth, Australia.,Department of Clinical Biochemistry, Clinipath Pathology, Perth, Australia
| | - Gerald F Watts
- School of Medicine, Faculty of Medicine and Health Sciences, The University of Western Australia, Perth, Australia.,Lipid Disorders Clinic, Department of Cardiology, Royal Perth Hospital, Perth, Australia
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16
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Gomez A, Colombo R, Pontoglio A, Helman L, Kaeser L, Giunta G, Parolin ML, Toscanini U, Cuniberti L. Functional analysis of six uncharacterised mutations in LDLR gene. Atherosclerosis 2019; 291:44-51. [PMID: 31689621 DOI: 10.1016/j.atherosclerosis.2019.10.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 01/12/2023]
Abstract
BACKGROUND AND AIMS Familial hypercholesterolemia (FH) is a primary hyperlipemia. It is an autosomal dominant genetic disorder of lipoproteins metabolism mainly caused by mutations in the low density lipoprotein receptor gene (LDLR). We aimed to investigate the functional impact on the low density lipoprotein receptor (LDLR) activity of six uncharacterised variants located in the coding region of the LDLR gene, namely c.428G > T, c.640T > C, c.1708C > T, c.1736A > T, c.1981C > G and c.2114C > G (NM_000527.4) and to attempt to define their clinical status. METHODS Functional studies were carried out using site-directed mutagenesis techniques and expression of LDLR protein in vitro. Results were correlated with clinical data and in silico analyses in order to assess the physiopathological role of these variants. RESULTS This work provides functional information about 6 uncharacterised mutations in LDLR. CONCLUSIONS The six variants studied here appeared to affect the LDLR function in vitro to different degrees, ranging from receptors with normal to slightly reduced activity to receptors exhibiting less than 10% of the wild-type activity. According to these studies and The American College of Medical Genetics and Genomics (ACMG) Standards and Guidelines, two variants could be classified as "Likely Benign" (p.(Ala705Gly) and p.(Leu570Phe)), three variants as "Pathogenic" (p.(Asp579Val), p.(Cys143Phe) and p.(Trp214Arg)) and one variant as "Likely Pathogenic" (p.(Pro661Ala)).
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Affiliation(s)
- Andrea Gomez
- Favaloro University, Lipids and Atherosclerosis Laboratory - IMETTyB - CONICET, Buenos Aires, Argentina; PRICAI-Favaloro Foundation, Buenos Aires, Argentina.
| | - Roberto Colombo
- Niguarda Ca' Granda Metropolitan Hospital, Center for the Study of Rare Hereditary Diseases, Milan, Italy; Faculty of Medicine Catholic University of the Sacred Heart, IRCCS "Agostino Gemelli" University Hospital, Rome, Italy
| | - Alessandro Pontoglio
- Niguarda Ca' Granda Metropolitan Hospital, Center for the Study of Rare Hereditary Diseases, Milan, Italy
| | - Lorena Helman
- Favaloro Foundation University Hospital, Metabolic Unit Service, Buenos Aires, Argentina
| | | | - Gustavo Giunta
- Favaloro University, Lipids and Atherosclerosis Laboratory - IMETTyB - CONICET, Buenos Aires, Argentina; Favaloro Foundation University Hospital, Metabolic Unit Service, Buenos Aires, Argentina
| | - Maria L Parolin
- Instituto de Diversidad y Evolución Austral. CCT Centpat-CONICET, Puerto Madryn, Argentina
| | | | - Luis Cuniberti
- Favaloro University, Lipids and Atherosclerosis Laboratory - IMETTyB - CONICET, Buenos Aires, Argentina
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17
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Banerjee P, Chan KC, Tarabocchia M, Benito-Vicente A, Alves AC, Uribe KB, Bourbon M, Skiba PJ, Pordy R, Gipe DA, Gaudet D, Martin C. Functional Analysis of LDLR (Low-Density Lipoprotein Receptor) Variants in Patient Lymphocytes to Assess the Effect of Evinacumab in Homozygous Familial Hypercholesterolemia Patients With a Spectrum of LDLR Activity. Arterioscler Thromb Vasc Biol 2019; 39:2248-2260. [PMID: 31578082 PMCID: PMC6818983 DOI: 10.1161/atvbaha.119.313051] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Supplemental Digital Content is available in the text. Homozygous familial hypercholesterolemia is a rare disease usually caused by LDLR (low-density lipoprotein receptor) mutations. Homozygous familial hypercholesterolemia is characterized by markedly elevated LDL-C (low-density lipoprotein cholesterol) levels and an extremely high risk of premature atherosclerotic cardiovascular disease. A phase 2, proof-of-concept study (NCT02265952) demonstrated that evinacumab, a fully human monoclonal antibody to ANGPTL3 (angiopoietin-like 3 protein), reduced LDL-C levels in 9 patients with genotypically confirmed homozygous familial hypercholesterolemia and was well tolerated. The aim of this study was to analyze the effects of evinacumab on LDLR activity in lymphocytes purified from patients in the proof-of-concept study.
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Affiliation(s)
- Poulabi Banerjee
- From Regeneron Pharmaceuticals, Inc, Tarrytown, NY (P.B., K-C.C., M.T., P.J.S., R.P., D.A.G.)
| | - Kuo-Chen Chan
- From Regeneron Pharmaceuticals, Inc, Tarrytown, NY (P.B., K-C.C., M.T., P.J.S., R.P., D.A.G.)
| | - Michel Tarabocchia
- From Regeneron Pharmaceuticals, Inc, Tarrytown, NY (P.B., K-C.C., M.T., P.J.S., R.P., D.A.G.)
| | - Asier Benito-Vicente
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, UPV/EHU, Spain (A.B-V., K.B.U, C.M.)
| | - Ana C Alves
- Unidade de I&D, Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal (A.C.A., M.B.)
| | - Kepa B Uribe
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, UPV/EHU, Spain (A.B-V., K.B.U, C.M.)
| | - Mafalda Bourbon
- Unidade de I&D, Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal (A.C.A., M.B.)
| | - Paul J Skiba
- From Regeneron Pharmaceuticals, Inc, Tarrytown, NY (P.B., K-C.C., M.T., P.J.S., R.P., D.A.G.)
| | - Robert Pordy
- From Regeneron Pharmaceuticals, Inc, Tarrytown, NY (P.B., K-C.C., M.T., P.J.S., R.P., D.A.G.)
| | - Daniel A Gipe
- From Regeneron Pharmaceuticals, Inc, Tarrytown, NY (P.B., K-C.C., M.T., P.J.S., R.P., D.A.G.)
| | - Daniel Gaudet
- Clinical Lipidology and Rare Lipid Disorders Unit, Department of Medicine, Université de Montréal Community Gene Medicine Center, Lipid Clinic Chicoutimi Hospital and ECOGENE-21 Clinical and Translational Research Center, Chicoutimi, Quebec, Canada (D.G.)
| | - Cesar Martin
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, UPV/EHU, Spain (A.B-V., K.B.U, C.M.)
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18
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Cao YX, Sun D, Liu HH, Jin JL, Li S, Guo YL, Wu NQ, Zhu CG, Gao Y, Dong QT, Liu G, Dong Q, Li JJ. A Novel Modified System of Simplified Chinese Criteria for Familial Hypercholesterolemia (SCCFH). Mol Diagn Ther 2019; 23:547-553. [PMID: 31172370 DOI: 10.1007/s40291-019-00405-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND OBJECTIVE The most significant clinical implication of familial hypercholesterolemia (FH) is early-onset coronary artery disease (CAD), highlighting the importance of a definitive diagnosis being available. Unfortunately, the existing algorithms are complex and it is often difficult to obtain information on the patient's family history. Hence, we aimed to establish a novel system of Simplified Chinese Criteria for FH (SCCFH). METHODS We recruited 12,921 participants undergoing routine blood collection from November 2011 to June 2018. Clinical characteristics, laboratory examination, and genetic testing were obtained. FH was diagnosed based on the Simon Broome (SB) criteria, Dutch Lipid Clinic Network (DLCN) criteria, and SCCFH. The sensitivity, specificity, and agreement of SCCFH to these existing criteria were investigated. RESULTS Of 12,921 participants reviewed, the prevalence of definite FH was 223 (1.73%), 202 (1.56%), and 205 (1.59%) based on the DLCN, SB, and SCCFH approaches, respectively. Compared with the DLCN and SB criteria, the SCCFH showed high sensitivity (91.9% and 100%), high specificity (100% and 99.9%), and good agreement (κ = 0.958 and 0.993). Similar results were found in several relevant clinical subgroups. CONCLUSIONS The SCCFH system is comparable to the existing criteria with high levels of sensitivity and specificity, and is easier to use clinically. Further larger prospective studies are needed to evaluate the feasibility and reliability of this system.
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Affiliation(s)
- Ye-Xuan Cao
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Di Sun
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Hui-Hui Liu
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Jing-Lu Jin
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Sha Li
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Yuan-Lin Guo
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Na-Qiong Wu
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Cheng-Gang Zhu
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Ying Gao
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Qiu-Ting Dong
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Geng Liu
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Qian Dong
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China
| | - Jian-Jun Li
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, BeiLiShi Road 167, Beijing, 100037, China.
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19
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Ma S, Sun W, Gao L, Liu S. Therapeutic targets of hypercholesterolemia: HMGCR and LDLR. Diabetes Metab Syndr Obes 2019; 12:1543-1553. [PMID: 31686875 PMCID: PMC6709517 DOI: 10.2147/dmso.s219013] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 07/25/2019] [Indexed: 12/14/2022] Open
Abstract
Cholesterol homeostasis is critical and necessary for the body's functions. Hypercholesterolemia can lead to significant clinical problems, such as cardiovascular disease (CVD). 3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) and low-density lipoprotein cholesterol receptor (LDLR) are major points of control in cholesterol homeostasis. We summarize the regulatory mechanisms of HMGCR and LDLR, which may provide insight for new drug design and development.
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Affiliation(s)
- Shizhan Ma
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan250021, People’s Republic of China
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital Affiliated to Shandong University, Jinan250021, People’s Republic of China
| | - Wenxiu Sun
- Department of Pharmacy, Taishan Vocational College of Nursing, Taian271000, People’s Republic of China
| | - Ling Gao
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan250021, People’s Republic of China
- Scientific Center, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan250021, People’s Republic of China
- Scientific Center, Shandong Provincial Hospital Affiliated to Shandong University, Jinan250021, People’s Republic of China
- Correspondence: Ling GaoScientific Center, Shandong Provincial Hospital Affiliated to Shandong University, 324 Jing 5 Road, Jinan, Shandong Province250021, People’s Republic of ChinaTel +86 531 6877 6910Email
| | - Shudong Liu
- Department of Endocrinology, Shandong Rongjun General Hospital, Jinan250013, People’s Republic of China
- Shudong LiuDepartment of Endocrinology, Shandong Rongjun General Hospital, 23 Jiefang Road, Jinan, Shandong Province250013, People’s Republic of ChinaTel +86 531 8238 2351Email
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20
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Benito-Vicente A, Siddiqi H, Uribe KB, Jebari S, Galicia-Garcia U, Larrea-Sebal A, Stef M, Ostolaza H, Palacios L, Martin C. p.(Asp47Asn) and p.(Thr62Met): non deleterious LDL receptor missense variants functionally characterized in vitro. Sci Rep 2018; 8:16614. [PMID: 30413722 PMCID: PMC6226515 DOI: 10.1038/s41598-018-34715-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 10/22/2018] [Indexed: 11/24/2022] Open
Abstract
Familial Hypercholesterolemia (FH) is a common genetic disorder caused most often by mutations in the Low Density Lipoprotein Receptor gene (LDLr) leading to high blood cholesterol levels, and ultimately to development of premature coronary heart disease. Genetic analysis and subsequent cascade screening in relatives allow diagnosis of FH at early stage, especially relevant to diagnose children. So far, more than 2300 LDLr variants have been described but only a minority of them have been functionally analysed to evaluate their pathogenicity in FH. Thus, identifying pathogenic mutations in LDLr is a long-standing challenge in the field. In this study, we investigated in vitro the activity p.(Asp47Asn) and p.(Thr62Met) LDLr variants, both in the LR1 region. We used CHO-ldlA7 transfected cells with plasmids carrying p.(Asp47Asn) or p.(Thr62Met) LDLr variants to analyse LDLr expression by FACS and immunoblotting, LDL binding and uptake was determined by FACS and analysis of mutation effects was assessed in silico. The in vitro activity assessment of p.(Asp47Asn) and p.(Thr62Met) LDLr variants shows a fully functional LDL binding and uptake activities. Therefore indicating that the three of them are non-pathogenic LDLr variants. These findings also emphasize the importance of in vitro functional LDLr activity studies to optimize the genetic diagnosis of FH avoiding the report of non-pathogenic variants and possible misdiagnose in relatives if cascade screening is carried out.
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Affiliation(s)
- A Benito-Vicente
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Apdo. 644, 48080, Bilbao, Spain
| | - H Siddiqi
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Apdo. 644, 48080, Bilbao, Spain
| | - K B Uribe
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Apdo. 644, 48080, Bilbao, Spain
| | - S Jebari
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Apdo. 644, 48080, Bilbao, Spain
| | - U Galicia-Garcia
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Apdo. 644, 48080, Bilbao, Spain
| | - A Larrea-Sebal
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Apdo. 644, 48080, Bilbao, Spain
| | - M Stef
- Progenika Biopharma, a Grifols Company, Derio, Spain
| | - H Ostolaza
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Apdo. 644, 48080, Bilbao, Spain
| | - L Palacios
- Progenika Biopharma, a Grifols Company, Derio, Spain
| | - C Martin
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Apdo. 644, 48080, Bilbao, Spain.
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Benito-Vicente A, Uribe KB, Jebari S, Galicia-Garcia U, Ostolaza H, Martin C. Familial Hypercholesterolemia: The Most Frequent Cholesterol Metabolism Disorder Caused Disease. Int J Mol Sci 2018; 19:ijms19113426. [PMID: 30388787 PMCID: PMC6275065 DOI: 10.3390/ijms19113426] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 10/21/2018] [Accepted: 10/29/2018] [Indexed: 12/18/2022] Open
Abstract
Cholesterol is an essential component of cell barrier formation and signaling transduction involved in many essential physiologic processes. For this reason, cholesterol metabolism must be tightly controlled. Cell cholesterol is mainly acquired from two sources: Dietary cholesterol, which is absorbed in the intestine and, intracellularly synthesized cholesterol that is mainly synthesized in the liver. Once acquired, both are delivered to peripheral tissues in a lipoprotein dependent mechanism. Malfunctioning of cholesterol metabolism is caused by multiple hereditary diseases, including Familial Hypercholesterolemia, Sitosterolemia Type C and Niemann-Pick Type C1. Of these, familial hypercholesterolemia (FH) is a common inherited autosomal co-dominant disorder characterized by high plasma cholesterol levels. Its frequency is estimated to be 1:200 and, if untreated, increases the risk of premature cardiovascular disease. This review aims to summarize the current knowledge on cholesterol metabolism and the relation of FH to cholesterol homeostasis with special focus on the genetics, diagnosis and treatment.
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Affiliation(s)
- Asier Benito-Vicente
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
| | - Kepa B Uribe
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
| | - Shifa Jebari
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
| | - Unai Galicia-Garcia
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
| | - Helena Ostolaza
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
| | - Cesar Martin
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
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22
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Benito-Vicente A, Uribe KB, Siddiqi H, Jebari S, Galicia-Garcia U, Larrea-Sebal A, Cenarro A, Stef M, Ostolaza H, Civeira F, Palacios L, Martin C. Replacement of cysteine at position 46 in the first cysteine-rich repeat of the LDL receptor impairs apolipoprotein recognition. PLoS One 2018; 13:e0204771. [PMID: 30332439 PMCID: PMC6192581 DOI: 10.1371/journal.pone.0204771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 09/13/2018] [Indexed: 11/18/2022] Open
Abstract
Background and aims Pathogenic mutations in the Low Density Lipoprotein Receptor gene (LDLR) cause Familial Hypercholesterolemia (FH), one of the most common genetic disorders with a prevalence as high as 1 in 200 in some populations. FH is an autosomal dominant disorder of lipoprotein metabolism characterized by high blood cholesterol levels, deposits of cholesterol in peripheral tissues such as tendon xanthomas and accelerated atherosclerosis. To date, 2500 LDLR variants have been identified in the LDLR gene; however, only a minority of them have been experimentally characterized and proven to be pathogenic. Here we investigated the role of Cys46 located in the first repeat of the LDL receptor binding domain in recognition of apolipoproteins. Methods Activity of the p.(Cys46Gly) LDLR variant was assessed by immunoblotting and flow cytometry in CHO-ldlA7 expressing the receptor variant. Affinity of p.(Cys46Gly) for LDL and VLDL was determined by solid-phase immunoassays and in silico analysis was used to predict mutation effects. Results and conclusion Functional characterization of p.(Cys46Gly) LDLR variant showed impaired LDL and VLDL binding and uptake activity. Consistent with this, solid-phase immunoassays showed the p.(Cys46Gly) LDLR variant has decreased binding affinity for apolipoproteins. These results indicate the important role of Cys46 in LDL receptor activity and highlight the role of LR1 in LDLr activity modulation. This study reinforces the significance of in vitro functional characterization of LDL receptor activity in developing an accurate approach to FH genetic diagnosis. This is of particular importance because it enables clinicians to tailor personalized treatments for patients’ mutation profile.
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Affiliation(s)
- A. Benito-Vicente
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain
| | - K. B. Uribe
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain
| | - H. Siddiqi
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain
| | - S. Jebari
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain
| | - U. Galicia-Garcia
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain
| | - A. Larrea-Sebal
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain
| | - A. Cenarro
- Unidad de Lípidos and Laboratorio de Investigación Molecular, Hospital Universitario Miguel Servet, Instituto Aragonés de Ciencias de la Salud (IACS), Zaragoza, Spain
| | - M. Stef
- Progenika Biopharma, a Grifols Company, Derio, Spain
| | - H. Ostolaza
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain
| | - F. Civeira
- Unidad de Lípidos and Laboratorio de Investigación Molecular, Hospital Universitario Miguel Servet, Instituto Aragonés de Ciencias de la Salud (IACS), Zaragoza, Spain
| | - L. Palacios
- Progenika Biopharma, a Grifols Company, Derio, Spain
| | - C. Martin
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain
- * E-mail:
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24
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Validation of LDLr Activity as a Tool to Improve Genetic Diagnosis of Familial Hypercholesterolemia: A Retrospective on Functional Characterization of LDLr Variants. Int J Mol Sci 2018; 19:ijms19061676. [PMID: 29874871 PMCID: PMC6032215 DOI: 10.3390/ijms19061676] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 05/28/2018] [Accepted: 06/04/2018] [Indexed: 12/11/2022] Open
Abstract
Familial hypercholesterolemia (FH) is an autosomal dominant disorder characterized by high blood-cholesterol levels mostly caused by mutations in the low-density lipoprotein receptor (LDLr). With a prevalence as high as 1/200 in some populations, genetic screening for pathogenic LDLr mutations is a cost-effective approach in families classified as ‘definite’ or ‘probable’ FH and can help to early diagnosis. However, with over 2000 LDLr variants identified, distinguishing pathogenic mutations from benign mutations is a long-standing challenge in the field. In 1998, the World Health Organization (WHO) highlighted the importance of improving the diagnosis and prognosis of FH patients thus, identifying LDLr pathogenic variants is a longstanding challenge to provide an accurate genetic diagnosis and personalized treatments. In recent years, accessible methodologies have been developed to assess LDLr activity in vitro, providing experimental reproducibility between laboratories all over the world that ensures rigorous analysis of all functional studies. In this review we present a broad spectrum of functionally characterized missense LDLr variants identified in patients with FH, which is mandatory for a definite diagnosis of FH.
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Chora JR, Medeiros AM, Alves AC, Bourbon M. Analysis of publicly available LDLR, APOB, and PCSK9 variants associated with familial hypercholesterolemia: application of ACMG guidelines and implications for familial hypercholesterolemia diagnosis. Genet Med 2017; 20:591-598. [PMID: 29261184 DOI: 10.1038/gim.2017.151] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 07/26/2017] [Indexed: 01/15/2023] Open
Abstract
PurposeFamilial hypercholesterolemia (FH) is an autosomal disorder of lipid metabolism presenting with increased cardiovascular risk. Although more than 1,700 variants have been associated with FH, the great majority have not been functionally proved to affect the low-density lipoprotein receptor cycle. We aimed to classify all described variants associated with FH and to establish the proportion of variants that lack evidence to support their pathogenicity.MethodsWe followed American College of Medical Genetics and Genomics (ACMG) guidelines for the classification, and collected information from a variety of databases and individual reports. A worldwide overview of publicly available FH variants was also performed.ResultsA total of 2,104 unique variants were identified as being associated with FH, but only 166 variants have been proven by complete in vitro functional studies to be causative of disease. Additionally, applying the ACMG guidelines, 1,097 variants were considered pathogenic or likely pathogenic. Only seven variants were found in all five continents.ConclusionThe lack of functional evidence for about 85% of all variants found in FH patients can compromise FH diagnosis and patient prognosis. ACMG classification improves variant interpretation, but functional studies are necessary to understand the effect of about 40% of all variants reported. Nevertheless, ACMG guidelines need to be adapted to FH for a better diagnosis.
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Affiliation(s)
- Joana Rita Chora
- Unidade I&D, Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisbon, Portugal.,University of Lisboa, Faculty of Sciences, BioISI-Biosystems & Integrative Sciences Institute, Lisbon, Portugal
| | - Ana Margarida Medeiros
- Unidade I&D, Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisbon, Portugal.,University of Lisboa, Faculty of Sciences, BioISI-Biosystems & Integrative Sciences Institute, Lisbon, Portugal
| | - Ana Catarina Alves
- Unidade I&D, Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisbon, Portugal.,University of Lisboa, Faculty of Sciences, BioISI-Biosystems & Integrative Sciences Institute, Lisbon, Portugal
| | - Mafalda Bourbon
- Unidade I&D, Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisbon, Portugal.,University of Lisboa, Faculty of Sciences, BioISI-Biosystems & Integrative Sciences Institute, Lisbon, Portugal
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Bourbon M, Alves AC, Alonso R, Mata N, Aguiar P, Padró T, Mata P. Mutational analysis and genotype-phenotype relation in familial hypercholesterolemia: The SAFEHEART registry. Atherosclerosis 2017; 262:8-13. [DOI: 10.1016/j.atherosclerosis.2017.04.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 03/29/2017] [Accepted: 04/05/2017] [Indexed: 12/26/2022]
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Bourbon M, Alves AC, Sijbrands EJ. Low-density lipoprotein receptor mutational analysis in diagnosis of familial hypercholesterolemia. Curr Opin Lipidol 2017; 28:120-129. [PMID: 28169869 DOI: 10.1097/mol.0000000000000404] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
PURPOSE OF REVIEW To present up to date evidence on the pathogenicity of low-density lipoprotein receptor (LDLR) variants and to propose a strategy that is suitable for implementation in the clinical work-up of familial hypercholesterolaemia. RECENT FINDINGS More than 1800 variants have been described in the LDLR gene of patients with a clinical diagnosis of familial hypercholesterolaemia; however, less than 15% have functional evidence of pathogenicity. SUMMARY The spectrum of variants in the LDLR identified in patients with clinical familial hypercholesterolaemia is increasing as novel variants are still being reported. However, over 50% of all LDLR variants need further evidence before they can be confirmed as mutations causing disease. Even with applying the recent American College of Medical Genetics variant classification, a large number of variants are still considered variants of unknown significance. Before obtaining an undisputable confirmation of the effect on the expression and activity of the LDLR, reporting these variants as part of a clinical diagnosis to the patient holds the risk that it might need to be withdrawn in a later stage. An investment should be made to develop functional assays to characterize LDLR variants of unknown significance for a better patient diagnosis and to prevent confusion in the physician's office.
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Affiliation(s)
- Mafalda Bourbon
- aUnidade de I&D, Grupo de Investigação Cardiovascular, Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge bBioISI - Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal cDepartment of internal Medicine, Erasmus University Rotterdam, Rotterdam, the Netherlands
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Leigh S, Futema M, Whittall R, Taylor-Beadling A, Williams M, den Dunnen JT, Humphries SE. The UCL low-density lipoprotein receptor gene variant database: pathogenicity update. J Med Genet 2016; 54:217-223. [PMID: 27821657 PMCID: PMC5502305 DOI: 10.1136/jmedgenet-2016-104054] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 10/06/2016] [Indexed: 12/04/2022]
Abstract
Background Familial hypercholesterolaemia (OMIM 143890) is most frequently caused by variations in the low-density lipoprotein receptor (LDLR) gene. Predicting whether novel variants are pathogenic may not be straightforward, especially for missense and synonymous variants. In 2013, the Association of Clinical Genetic Scientists published guidelines for the classification of variants, with categories 1 and 2 representing clearly not or unlikely pathogenic, respectively, 3 representing variants of unknown significance (VUS), and 4 and 5 representing likely to be or clearly pathogenic, respectively. Here, we update the University College London (UCL) LDLR variant database according to these guidelines. Methods PubMed searches and alerts were used to identify novel LDLR variants for inclusion in the database. Standard in silico tools were used to predict potential pathogenicity. Variants were designated as class 4/5 only when the predictions from the different programs were concordant and as class 3 when predictions were discordant. Results The updated database (http://www.lovd.nl/LDLR) now includes 2925 curated variants, representing 1707 independent events. All 129 nonsense variants, 337 small frame-shifting and 117/118 large rearrangements were classified as 4 or 5. Of the 795 missense variants, 115 were in classes 1 and 2, 605 in class 4 and 75 in class 3. 111/181 intronic variants, 4/34 synonymous variants and 14/37 promoter variants were assigned to classes 4 or 5. Overall, 112 (7%) of reported variants were class 3. Conclusions This study updates the LDLR variant database and identifies a number of reported VUS where additional family and in vitro studies will be required to confirm or refute their pathogenicity.
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Affiliation(s)
- Sarah Leigh
- Centre for Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, UK
| | - Marta Futema
- Centre for Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, UK
| | - Ros Whittall
- Centre for Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, UK
| | | | - Maggie Williams
- Bristol Genetics Laboratory, Pathology Sciences, Blood Sciences and Bristol Genetics, Southmead Hospital, Bristol, UK
| | - Johan T den Dunnen
- Clinical Genetics and Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Steve E Humphries
- Centre for Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, UK
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Clinical and molecular characteristics of homozygous familial hypercholesterolemia patients: Insights from SAFEHEART registry. J Clin Lipidol 2016; 10:953-961. [DOI: 10.1016/j.jacl.2016.04.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 04/12/2016] [Accepted: 04/12/2016] [Indexed: 11/24/2022]
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