1
|
Establishing the Mutational Spectrum of Hungarian Patients with Familial Hypercholesterolemia. Genes (Basel) 2022; 13:genes13010153. [PMID: 35052492 PMCID: PMC8775528 DOI: 10.3390/genes13010153] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/11/2022] [Accepted: 01/11/2022] [Indexed: 02/05/2023] Open
Abstract
Familial hypercholesterolemia (FH) is one of the most common autosomal, dominantly inherited diseases affecting cholesterol metabolism, which, in the absence of treatment, leads to the development of cardiovascular complications. The disease is still underdiagnosed, even though an early diagnosis would be of great importance for the patient to receive proper treatment and to prevent further complications. No studies are available describing the genetic background of Hungarian FH patients. In this work, we present the clinical and molecular data of 44 unrelated individuals with suspected FH. Sequencing of five FH-causing genes (LDLR, APOB, PCSK9, LDLRAP1 and STAP1) has been performed by next-generation sequencing (NGS). In cases where a copy number variation (CNV) has been detected by NGS, confirmation by multiplex ligation-dependent probe amplification (MLPA) has also been performed. We identified 47 causal or potentially causal (including variants of uncertain significance) LDLR and APOB variants in 44 index patients. The most common variant in the APOB gene was the c.10580G>A p.(Arg3527Gln) missense alteration, this being in accordance with literature data. Several missense variants in the LDLR gene were detected in more than one index patient. LDLR variants in the Hungarian population largely overlap with variants detected in neighboring countries.
Collapse
|
2
|
Smyth N, Ramsay M, Raal FJ. Population specific genetic heterogeneity of familial hypercholesterolemia in South Africa. Curr Opin Lipidol 2018; 29:72-79. [PMID: 29369830 DOI: 10.1097/mol.0000000000000488] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW To describe the prevalence and population-specific genetic heterogeneity of familial hypercholesterolemia in South Africa. RECENT FINDINGS This review highlights the paucity of data on familial hypercholesterolemia in South Africa, and the urgent need to uncover the mutation profiles in lipid-associated genes, causing an increase in LDL-cholesterol in the different ethnic groups. Case reports and small studies have shown that familial hypercholesterolemia, although apparently uncommon, is present in black Africans. SUMMARY Local founder effects have led to an increased prevalence of familial hypercholesterolemia in several South African populations: Afrikaner founder mutations (c.681 C>G, c.1285 G>A, c.523 G>A), Ashkenazi founder mutation (c.654_656del) and possible Indian founder mutation (c.2054 C>T). Preliminary data in black Africans with elevated LDL-cholesterol identified a possible common mutation, c.137_142del. The South African multiethnic society and well described founder effects emphasize the need for differential approaches to diagnosis and management of familial hypercholesterolemia. Studies involving larger cohorts and inclusive of different ethnicities are paramount to establishing an accurate prevalence of familial hypercholesterolemia in black Africans, not only in South Africa but in the Sub-Saharan African region. It is clear that the estimated world prevalence of one in 250 cannot be generally applied across African populations.
Collapse
Affiliation(s)
| | | | - Frederick J Raal
- Department of Medicine, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
| |
Collapse
|
3
|
Fairoozy RH, Futema M, Vakili R, Abbaszadegan MR, Hosseini S, Aminzadeh M, Zaeri H, Mobini M, Humphries SE, Sahebkar A. The Genetic Spectrum of Familial Hypercholesterolemia (FH) in the Iranian Population. Sci Rep 2017; 7:17087. [PMID: 29213121 PMCID: PMC5719081 DOI: 10.1038/s41598-017-17181-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/15/2017] [Indexed: 12/16/2022] Open
Abstract
Familial hypercholesterolemia (FH) is an autosomal dominant disorder associated with premature cardiovascular disease (CVD). Mutations in the LDLR, APOB, and PCSK9 genes are known to cause FH. In this study, we analysed the genetic spectrum of the disease in subjects from the Iranian population with a clinical diagnosis of FH. Samples were collected from 16 children and family members from five different cities of Iran. Probands were screened for mutations in the LDLR, APOB, and PCSK9 genes using next generation sequencing, with results confirmed by Sanger sequencing. The likely pathology of identified variants was examined using in silico tools. Of the probands, 14 had a clinical diagnosis of homozygous FH and two of heterozygous FH. No mutations were found in either APOB or PCSK9, but nine probands were homozygous for seven different LDLR mutations, with p.(Trp577Arg) occurring in three and p.Val806Glyfs*11 occurring in two patients. Two mutations were novel: p.(Leu479Gln) and p.(Glu668*). Seven probands with a clinical diagnosis of FH were mutation negative. This pilot study, integrating clinical and molecular-based techniques, begins to elucidate the FH heterogeneity and the mutation spectrum in the Iranian population. Such information is important for future disease management and cost savings.
Collapse
Affiliation(s)
- R H Fairoozy
- Cardiovascular Genetics, Institute of Cardiovascular Science, University College London, London, United Kingdom.,Molecular Diagnostic Unit, Clinical Laboratory Department, King Abdullah Medical city in Makkah, Makkah, Saudi Arabia
| | - M Futema
- Centre for Cardiology in the Young, Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - R Vakili
- Department of Pediatric Endocrinology and Metabolism, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - M R Abbaszadegan
- Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - S Hosseini
- Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - M Aminzadeh
- Diabetes Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - H Zaeri
- Neonatal and Children Health Research Centre, Golestan University of Medical Sciences, Gorgan, Iran
| | - M Mobini
- School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - S E Humphries
- Cardiovascular Genetics, Institute of Cardiovascular Science, University College London, London, United Kingdom.
| | - A Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.,School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| |
Collapse
|
4
|
Setia N, Saxena R, Arora A, Verma IC. Spectrum of mutations in homozygous familial hypercholesterolemia in India, with four novel mutations. Atherosclerosis 2016; 255:31-36. [PMID: 27816806 DOI: 10.1016/j.atherosclerosis.2016.10.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 10/10/2016] [Accepted: 10/13/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND AIMS Homozygous familial hypercholesterolemia (FH) is a rare but serious, inherited disorder of lipid metabolism characterized by very high total and LDL cholesterol levels from birth. It presents as cutaneous and tendon xanthomas since childhood, with or without cardiac involvement. FH is commonly caused by mutations in three genes, i.e. LDL receptor (LDLR), apolipoprotein B (ApoB) and PCSK9. We aimed to determine the spectrum of mutations in cases of homozygous FH in Asian Indians and evaluate if there was any similarity to the mutations observed in Caucasians. METHODS Sixteen homozygous FH subjects from eleven families were analyzed for mutations by Sanger sequencing. Large rearrangements in LDLR gene were evaluated by multiplex ligation probe dependent amplification (MLPA) technique. RESULTS Ten mutations were observed in LDLR gene, of which four mutations were novel. No mutation was detected in ApoB gene and common PCSK9 mutation (p.D374Y). Fourteen cases had homozygous mutations; one had compound heterozygous mutation, while no mutation was detected in one clinically homozygous case. We report an interesting "Triple hit" case with features of homozygous FH. CONCLUSIONS The spectrum of mutations in the Asian Indian population is quite heterogeneous. Of the mutations identified, 40% were novel. No mutation was observed in exons 3, 9 and 14 of LDLR gene, which are considered to be hot spots in studies done on Asian Indians in South Africa. Early detection followed by aggressive therapy, and cascade screening of extended families has been initiated to reduce the morbidity and mortality in these patients.
Collapse
Affiliation(s)
- Nitika Setia
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, 110060, India.
| | - Renu Saxena
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, 110060, India
| | - Anjali Arora
- Hyperlipidemia Prevention Clinic, Department of Cardiology, Sir Ganga Ram Hospital, New Delhi, 110060, India
| | - Ishwar C Verma
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, 110060, India
| |
Collapse
|
5
|
Use of targeted exome sequencing in genetic diagnosis of Chinese familial hypercholesterolemia. PLoS One 2014; 9:e94697. [PMID: 24722143 PMCID: PMC3983231 DOI: 10.1371/journal.pone.0094697] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 03/18/2014] [Indexed: 12/23/2022] Open
Abstract
Familial hypercholesterolemia is an autosomal dominant inherited disease characterized by elevated plasma low-density lipoprotein cholesterol (LDL-C). It is mainly caused by mutations of the low-density lipoprotein receptor (LDLR) gene. Currently, the methods of whole genome sequencing or whole exome sequencing for screening mutations in familial hypercholesterolemia are not applicable in China due to high cost. We performed targeted exome sequencing of 167 genes implicated in the homozygous phenotype of a proband pedigree to identify candidate mutations, validated them in the family of the proband, studied the functions of the mutant protein, and followed up serum lipid levels after treatment. We discovered that exon 9 c.1268 T>C and exon 8 c.1129 T>G compound heterozygous mutations in the LDLR gene in the proband derived from the mother and father, respectively, in which the mutation of c.1129 T>G has not been reported previously. The mutant LDL-R protein had 57% and 52% binding and internalization functions, respectively, compared with that of the wild type. After 6 months of therapy, the LDL-C level of the proband decreased by more than 50% and the LDL-C of the other family members with heterozygous mutation also reduced to normal. Targeted exome sequencing is an effective method for screening mutation genes in familial hypercholesterolemia. The exon 8 and 9 mutations of the LDLR gene were pedigree mutations. The functions of the mutant LDL-R protein were decreased significantly compared with that of the wild type. Simvastatin plus ezetimibe was proven safe and effective in this preschool-age child.
Collapse
|
6
|
Ajmal M, Ahmed W, Sadeque A, Ali SHB, Bokhari SH, Ahmed N, Qamar R. Identification of a recurrent insertion mutation in the LDLR gene in a Pakistani family with autosomal dominant hypercholesterolemia. Mol Biol Rep 2010; 37:3869-75. [DOI: 10.1007/s11033-010-0043-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2009] [Accepted: 02/24/2010] [Indexed: 11/27/2022]
|
7
|
Brusgaard K, Jordan P, Hansen H, Hansen AB, Hørder M. Molecular genetic analysis of 1053 Danish individuals with clinical signs of familial hypercholesterolemia. Clin Genet 2006; 69:277-83. [PMID: 16542394 DOI: 10.1111/j.1399-0004.2006.00585.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The lipid disorder familial hypercholesterolemia (FH) predisposes to cardiovascular disease. With a prevalence of approximately one in 500 in the general Caucasian population, FH is one of the most frequent single-gene disorders. As the mutational spectra vary between populations, it is crucial to identify the mutations in a given population in order to implement a molecular genetic screening strategy. A total of 1053 referred individuals with clinical signs of FH were investigated, and mutations were identified in 425 individuals. Fifty-four different mutations were identified, of which 13 are novel. The five most frequent mutations accounted for 56.3% of all disease-causing mutations. The majority of the remaining mutations were of a private nature only encountered in single families. In this study, a reliable molecular genetic screening protocol was established, and the relevance of performing presymptomatic genetic analysis as part of a preventive strategy was documented. We have acquired knowledge of the mutational spectra in the Danish population and thus will be able to trace mutations in their relatives through our index cases.
Collapse
Affiliation(s)
- K Brusgaard
- Department of Clinical Biochemistry and Clinical Genetics, Odense University Hospital, Odense C, Denmark.
| | | | | | | | | |
Collapse
|
8
|
Muller PY, Miserez AR. Large heterogeneity of mutations in the gene encoding the low-density lipoprotein receptor in subjects with familial hypercholesterolaemia. ATHEROSCLEROSIS SUPP 2004; 5:1-5. [PMID: 15556092 DOI: 10.1016/j.atherosclerosissup.2004.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular genetic testing for presymptomatic identification of subjects affected by familial hypercholesterolaemia (FH) is difficult due to the heterogeneity of the mutations in the gene encoding the low-density lipoprotein receptor (LDLR) in most populations. This investigation presents a detailed analysis of comparable, country-specific prevalence data of LDLR mutations in subjects with clinically defined FH and assesses the heterogeneous mutation diversity observed in most geographic regions.
Collapse
Affiliation(s)
- Patrick Y Muller
- Department of Clinical-Biological Sciences, Cardiovascular Genetics, Institute of Biochemistry and Genetics, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland
| | | |
Collapse
|
9
|
Dedoussis GVZ, Skoumas J, Pitsavos C, Choumerianou DM, Genschel J, Schmidt H, Stefanadis C. FH clinical phenotype in Greek patients with LDL-R defective vs. negative mutations. Eur J Clin Invest 2004; 34:402-9. [PMID: 15200491 DOI: 10.1111/j.1365-2362.2004.01351.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Familial hypercholesterolaemia (FH) is caused by mutations in the low-density lipoprotein receptor gene and the gene encoding apolipoprotein B-100, affecting one in 500 individuals. METHODS One hundred and eighty-three Greek FH patients were screened for mutations on the LDLR and ApoB genes. RESULTS We identified mutations in 67 probands and 11 relatives. Sixteen mutations located in eight different exons and the promoter of the LDLR were discovered. Among them 10 were missense mutations (C6W, S265R, A370T, Q363P, D365E, V408M, A410T, A517T, G528D, G571E), two were nonsense mutations (Q363X and C660X), three were splice defects (2140 + 5G-->A and 2140 + 9C-->T, 1706 - 10G-->A), and one was a nucleotide substitution (- 45delT) on the promoter. None of the subjects carried any apoB mutation. The detection rate of mutations in this study was 43%. From the above mutations, A410T, A519T and the splice site defects 2140 + 9C-->T were detected for the first time in the Greek population. Among them V408M, G528D, C6W and S265R account for 73% of heterozygous FH probands. V408M mutation is more common in Central West, while C6W is more common in Central East. Separating the patients into two groups (receptor defective and receptor negative) we found that the receptor negative group had higher levels of total cholesterol, low-density lipoprotein cholesterol and higher prevalence of tendon xanthomas compared with the receptor-defective group. DISCUSSION The homogenous molecular basis of familial hypercholesterolaemia in Greece facilitates the application of a DNA diagnostic strategy based on the origin of the patient. The early mutation analysis would add valuable information on the severity of the disease.
Collapse
Affiliation(s)
- G V Z Dedoussis
- Laboratory of Molecular Biology, Department of Science of Dietetics-Nutrition, Harokopio University of Athens, Athens, Greece.
| | | | | | | | | | | | | |
Collapse
|
10
|
Lind S, Rystedt E, Eriksson M, Wiklund O, Angelin B, Eggertsen G. Genetic characterization of Swedish patients with familial hypercholesterolemia: a heterogeneous pattern of mutations in the LDL receptor gene. Atherosclerosis 2002; 163:399-407. [PMID: 12052488 DOI: 10.1016/s0021-9150(02)00038-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Familial hypercholesterolemia (FH) is an autosomal codominant disease, caused by mutations in the LDL receptor gene. To characterize the distribution of genetic aberrations in Swedish FH-patients fulfilling the clinical criteria of FH, we have investigated 150 unrelated Swedish patients for mutations in the LDL receptor gene and for the most common mutation causing familial ligand defective apo B-100 (FDB). Of the patients, 77 were recruited from Huddinge University Hospital in Stockholm and 73 from Sahlgren's University Hospital in Göteborg. Screening was carried out using SSCP and Southern blotting techniques, combined with DNA sequence analysis. In total, mutations regarded as cause for disease were identified in 55 patients (37%), representing 32 different types of mutations. In the LDL receptor gene we detected four nonsense mutations, 13 missense mutations, seven splice junction mutations, and four major rearrangements. In addition, two small deletions were identified and one base exchange in the promoter region. The most common mutation (apo B3500) causing FDB was found in three patients. The most frequent mutation was FH-Helsinki, reflecting the admixture of Finnish immigrants. We further identified 15 point mutations which were not considered to affect the function of the gene, and thus were regarded as polymorphic changes. This multitude of mutations reflects a heterogeneous genetic background in our series of Swedish FH-patients and differs from the situation in the other Scandinavian countries. Future studies should aim at characterizing the importance of other genes for the development of the FH phenotype.
Collapse
Affiliation(s)
- S Lind
- Department of Medical Laboratory Sciences and Technology, Centre for Inherited Metabolic Diseases, Karolinska Institute at Huddinge University Hospital, S-141 86 Stockholm, Sweden.
| | | | | | | | | | | |
Collapse
|
11
|
Abstract
Atherosclerotic coronary disease develops over several decades and was once thought to be an inevitable, irreversible consequence of aging. Atherogenesis is an inflammatory response that occurs after injury to the endothelium. Thrombosis, because of either endothelial erosion or plaque disruption, precipitates acute coronary events. Effective lipid lowering with statins has consistently and significantly decreased the risk that acute ischemic events will occur. The beneficial effects of statins likely result not only from their lipid-lowering effects but also from mechanisms that influence plaque behavior. Atherosclerotic plaques are not immutable; rather, their structure and composition can be altered by therapeutic modification. Ample evidence from clinical trials supports statin treatment in patients with stable coronary disease. Results of recent clinical trials support early treatment of high-risk patients with unstable coronary disease; early and aggressive statin treatment resulted in fewer recurrent ischemic events in patients with an acute coronary syndrome. Additional studies are needed to confirm the benefit of early statin treatment in patients with unstable coronary disease and to elucidate the reasons for the occurrence of events in treated patients. Research is also necessary to clarify the role of other lipids, as well as nonlipid risk factors, in the occurrence of acute ischemic events.
Collapse
Affiliation(s)
- M J Davies
- British Heart Foundation, Cardiovascular Pathology Research Group, St. George's Hospital Medical School, University of London, London, United Kingdom.
| |
Collapse
|
12
|
Salazar LA, Hirata MH, Quint�o �C, Hirata RD. Lipid-lowering response of the HMG-CoA reductase inhibitor fluvastatin is influenced by polymorphisms in the low-density lipoprotein receptor gene in Brazilian patients with primary hypercholesterolemia. J Clin Lab Anal 2000. [DOI: 10.1002/(sici)1098-2825(2000)14:3<125::aid-jcla7>3.0.co;2-s] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
13
|
Ekström U, Abrahamson M, Florén CH, Tollig H, Wettrell G, Nilsson G, Sun XM, Soutar AK, Nilsson-Ehle P. An individual with a healthy phenotype in spite of a pathogenic LDL receptor mutation (C240F). Clin Genet 1999; 55:332-9. [PMID: 10422803 DOI: 10.1034/j.1399-0004.1999.550506.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Familial hypercholesterolemia (FH) is caused by a defect in the function of the low density lipoprotein (LDL) receptor and inherited in an autosomal, codominant way. In this study we present a 13-year-old girl, compound heterozygote for the LDL receptor mutations C240F and Y167X. Fibroblasts from the patient showed very low cholesterol esterification rate, LDL uptake, and degradation compared to normal fibroblasts (< 2%, 8%, and < 2%, respectively). The C240F mutant was expressed in LDL receptor deficient CHOMldlA7 cells. Analysis of cell extracts by immunoblotting demonstrated delayed processing of the mutated LDL receptor, which was accumulated as a precursor protein of normal size. A high molecular weight form of the receptor was also detectable in these cells, which probably reflects cross-linking through the unpaired cysteine residue in the binding domain. Cells expressing the C240F mutant protein were unable to mediate uptake and degradation of LDL. The two siblings of the index case also carried the C240F mutation, but surprisingly one of them (a 17-year-old brother) showed no signs of hypercholesterolemia. This observation is consistent with the view that there may be cholesterol lowering mechanisms that can be activated, perhaps by mutations in known or hitherto unknown genes.
Collapse
Affiliation(s)
- U Ekström
- Institute of Laboratory Medicine, Department of Clinical Chemistry, Lund University Hospital, Sweden.
| | | | | | | | | | | | | | | | | |
Collapse
|