BACKGROUND: Large deletions and duplications within the low-density lipoprotein receptor (LDLR) gene make up approximately 10% of LDLR pathogenic variants found in Czech patients with familial hypercholesterolemia. The goal of this study was to test the hypothesis that all probands with each rearrangement share identical breakpoints inherited from a common ancestor and to determine the role of Alu repetitive elements in the generation of these rearrangements. METHODS: The breakpoint sequence was determined by PCR amplification and Sanger sequencing. To confirm the breakpoint position, an NGS analysis was performed. Haplotype analysis of common LDLR variants was performed using PCR and Sanger sequencing. RESULTS: The breakpoints of 8 rearrangements within the LDLR gene were analysed, including the four most common LDLR rearrangements in the Czech population (number of probands ranging from 8 to 28), and four less common rearrangements (1-4 probands). Probands with a specific rearrangement shared identical breakpoint positions and haplotypes associated with the rearrangement, suggesting a shared origin from a common ancestor. All breakpoints except for one were located inside an Alu element. In 6 out of 8 breakpoints, there was high homology (≥ 70%) between the two Alu repeats in which the break occurred. CONCLUSIONS: The most common rearrangements of the LDLR gene in the Czech population likely arose from one mutational event. Alu elements likely played a role in the generation of the majority of rearrangements inside the LDLR gene.

• MeSH
• genová přestavba MeSH
• hyperlipoproteinemie typ II * genetika   epidemiologie   MeSH
• lidé MeSH
• mutace MeSH
• receptory LDL genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Familiární hypercholesterolemie je jedno z nejčastějších metabolických onemocnění. Nejčastěji je spojována s patogenními variantami v genu pro LDL-receptorový protein (LDLR). Ve veřejných databázích je popsáno již více než 2 700 variant, které byly v tomto genu celosvětově nalezeny. I přes zásadní technologické pokroky v molekulární biologii zůstává stěžejním úkolem interpretace nalezených sekvenčních variant ve vztahu ke konkrétnímu hodnocenému klinickému projevu u konkrétního pacienta. V rámci mezinárodní expertní skupiny byla vypracována kritéria pro hodnocení kauzality sekvenčních variant v genu LDLR ve snaze sjednotit rozdílné interpretační algoritmy. Tato kritéria by následně měla být aplikována do klinické a diagnostické praxe.

Familial hypercholesterolemia is one of the most common metabolic diseases. It is mostly associated with pathogenic variants in the LDLR gene. Public databases contain more than 3,000 sequence variants that have been reported in this gene worldwide. Despite crucial technological advances in molecular biology, the interpretation of detected sequence variants in relation to the specific evaluated clinical phenotype in a particular patient remains a key task. Within an international expert group, criteria for evaluation of causality of sequence variants in the LDLR gene were developed to unify different interpretation algorithms. These criteria should then be applied to the clinical and diagnostic practice.

• MeSH
• diagnostické techniky molekulární MeSH
• frekvence genu MeSH
• genetická variace MeSH
• hyperlipoproteinemie typ II * diagnóza   genetika   MeSH
• lidé MeSH
• receptory LDL genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH

BACKGROUND AND AIMS: Familial hypercholesterolaemia (FH) is commonly caused by mutations in the LDLR, APOB or PCSK9 genes, with untreated mean low density lipoprotein-cholesterol (LDL-C) concentrations being elevated in APOB mutation carriers, even higher in LDLR mutation and highest in those with a PCSK9 mutation. Here we examine this in children with FH from Norway, UK, The Netherlands, Belgium, Czech Republic, Austria, Portugal and Greece. METHODS: Differences in characteristics and pre- and post-treatment lipid concentrations in those with different molecular causes were compared by standard statistical tests. RESULTS: Data were obtained from 2866 children, of whom 2531 (88%) carried a reported LDLR/APOB/PCSK9 variant. In all countries, the most common cause of FH was an LDLR mutation (79% of children, 297 different), but the prevalence of the APOB p.(Arg3527Gln) mutation varied significantly (ranging from 0% in Greece to 39% in Czech Republic, p < 2.2 × 10-16). The prevalence of a family history of premature CHD was significantly higher in children with an LDLR vs APOB mutation (16% vs 7% p=0.0005). Compared to the LDLR mutation group, mean (±SD) concentrations of pre-treatment LDL-C were significantly lower in those with an APOB mutation (n = 2260 vs n = 264, 4.96 (1.08)mmol/l vs 5.88 (1.41)mmol/l, p < 2.2 × 10-16) and lowest in those with a PCSK9 mutation (n = 7, 4.71 (1.22)mmol/l). CONCLUSIONS: The most common cause of FH in children from eight European countries was an LDLR mutation, with the prevalence of the APOB p.(Arg3527Gln) mutation varying significantly across countries. In children, LDLR-FH is associated with higher concentrations of LDL-C and family history of CHD compared to those with APOB-FH.

• MeSH
• dítě MeSH
• hyperlipoproteinemie typ II * diagnóza   epidemiologie   genetika   MeSH
• lidé MeSH
• lipidy MeSH
• mutace MeSH
• mutační analýza DNA MeSH
• proproteinkonvertasa subtilisin/kexin typu 9 * genetika   MeSH
• receptory LDL genetika   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Belgie MeSH
• Česká republika MeSH
• Evropa MeSH
• Nizozemsko MeSH
• Norsko MeSH
• Portugalsko MeSH
• Rakousko MeSH
• Řecko MeSH

Familial hypercholesterolemia (FH) is an autosomal dominant disease with frequency of 1/200-500, associated with mutations in the LDLR, APOB, or PCSK9 genes. The aim of the project is application of techniques for functional analysis of mutations in the LDLR gene. This approach established on expression of wild-type and mutant proteins and their analyses using confocal laser scanning microscopy will be complemented by determination of the structural impact of mutations using in silico tools. The finding of molecular mechanisms relating to mutations and their effects on the protein structure/function is important for determination of the causality of identified genetic variants and acquisition of new information about the FH pathogenesis. Further, reanalysis of previous results of DNA analyses will be performed with the aim to select patients which undergone DNA analysis with negative results but these could have been affected by different sensitivity of diagnostic approaches using in the course of 18 years of DNA diagnostics of FH in the CR.

Familiární hypercholesterolémie (FH) je autosomálně dominantní onemocnění s frekvencí 1/200-500 spojené s mutacemi v genech LDLR, APOB a PCSK9. Cílem projektu je zavedení a aplikace technik pro funkční analýzu mutací v LDLR. Tento přístup založený na expresi standardních a mutantních proteinů a jejich analýze pomocí konfokální laserové skenovací mikroskopie bude doplněn stanovením strukturního dopadu mutací pomocí in silico přístupů. Nalezení molekulárních mechanismů spojených s mutací a jejím vlivem na funkci a strukturu kódovaného proteinu je důležité pro stanovení kauzality identifikovaných genetických variant a získání nových informací týkajících se patogenézy FH. Znalost funkčního vlivu mutací je velmi důležitá pro diagnostiku FH, ale stále chybějící pro většinu mutací typu missense. Dále bude provedena re-analýza dosavadních výsledků genetické diagnostiky FH s cílem vytypovat pacienty, kteří prošli analýzou DNA s negativním výsledkem, ale tento mohl být ovlivněn různou citlivostí diagnostických metod používaných v průběhu 18 let genetické diagnostiky FH v ČR.

• MeSH
• apolipoproteiny B genetika   MeSH
• hyperlipoproteinemie typ II genetika   MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• proproteinkonvertasa subtilisin/kexin typu 9 genetika   MeSH
• receptory LDL genetika   MeSH
• stanovení celkové genové exprese MeSH
• Check Tag
• lidé MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• molekulární biologie, molekulární medicína
• vnitřní lékařství
• genetika, lékařská genetika
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

Our objective was to investigate the effect of cholesterol [hypercholesterolemia and 7-ketocholesterol (7K)] on endoglin (Eng) expression and regulation with respect to endothelial or vascular dysfunction in vivo and in vitro. In vivo experiments were performed in 2-mo-old atherosclerosis-prone apolipoprotein E-deficient/LDL receptor-deficient (ApoE-/-/LDLR-/-) female mice and their wild-type C57BL/6J littermates. In in vitro experiments, human aortic endothelial cells (HAECs) were treated with 7K. ApoE-/-/LDLR-/- mice developed hypercholesterolemia accompanied by increased circulating levels of P-selectin and Eng and a disruption of NO metabolism. Functional analysis of the aorta demonstrated impaired vascular reactivity, and Western blot analysis revealed down-regulation of membrane Eng/Smad2/3/eNOS signaling in ApoE-/-/LDLR-/- mice. 7K increased Eng expression via Krüppel-like factor 6 (KLF6), liver X nuclear receptor, and NF-κB in HAECs. 7K-induced Eng expression was prevented by the treatment with 2-hydroxypropyl-β-cyclodextrin; 8-{[5-chloro-2-(4-methylpiperazin-1-yl) pyridine-4-carbonyl] amino}-1-(4-fluorophenyl)-4, 5-dihydrobenzo[g]indazole-3-carboxamide; or by KLF6 silencing. 7K induced increased adhesion and transmigration of monocytic human leukemia promonocytic cell line cells and was prevented by Eng silencing. We concluded that hypercholesterolemia altered Eng expression and signaling, followed by endothelial or vascular dysfunction before formation of atherosclerotic lesions in ApoE-/-/LDLR-/- mice. By contrast, 7K increased Eng expression and induced inflammation in HAECs, which was followed by an increased adhesion and transmigration of monocytes via endothelium, which was prevented by Eng inhibition. Thus, we propose a relevant role for Eng in endothelial or vascular dysfunction or inflammation when exposed to cholesterol.-Vicen, M., Vitverova, B., Havelek, R., Blazickova, K., Machacek, M., Rathouska, J., Najmanová, I., Dolezelova, E., Prasnicka, A., Sternak, M., Bernabeu, C., Nachtigal, P. Regulation and role of endoglin in cholesterol-induced endothelial and vascular dysfunction in vivo and in vitro.

• MeSH
• aorta cytologie   metabolismus   patologie   MeSH
• apolipoproteiny E genetika   MeSH
• aterosklerotický plát etiologie   genetika   metabolismus   MeSH
• beta-cyklodextriny farmakologie   MeSH
• cévní endotel účinky léků   metabolismus   patologie   MeSH
• cholesterol metabolismus   MeSH
• endoglin genetika   metabolismus   MeSH
• hypercholesterolemie komplikace   genetika   metabolismus   MeSH
• indazoly farmakologie   MeSH
• KLF6 metabolismus   MeSH
• kultivované buňky MeSH
• kyseliny isonikotinové farmakologie   MeSH
• lidé MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• NF-kappa B metabolismus   MeSH
• oxid dusnatý metabolismus   MeSH
• P-selektin metabolismus   MeSH
• proteiny Smad metabolismus   MeSH
• receptory LDL genetika   MeSH
• synthasa oxidu dusnatého, typ III metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Although awareness of familial hypercholesterolemia (FH) is increasing, this common, potentially fatal, treatable condition remains underdiagnosed. Despite FH being a genetic disorder, genetic testing is rarely used. The Familial Hypercholesterolemia Foundation convened an international expert panel to assess the utility of FH genetic testing. The rationale includes the following: 1) facilitation of definitive diagnosis; 2) pathogenic variants indicate higher cardiovascular risk, which indicates the potential need for more aggressive lipid lowering; 3) increase in initiation of and adherence to therapy; and 4) cascade testing of at-risk relatives. The Expert Consensus Panel recommends that FH genetic testing become the standard of care for patients with definite or probable FH, as well as for their at-risk relatives. Testing should include the genes encoding the low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), and proprotein convertase subtilisin/kexin 9 (PCSK9); other genes may also need to be considered for analysis based on patient phenotype. Expected outcomes include greater diagnoses, more effective cascade testing, initiation of therapies at earlier ages, and more accurate risk stratification.

• MeSH
• apolipoproteiny B krev   genetika   MeSH
• genetické poradenství metody   normy   MeSH
• genetické testování metody   normy   MeSH
• hyperlipoproteinemie typ II krev   diagnóza   genetika   MeSH
• lidé MeSH
• proproteinkonvertasa subtilisin/kexin typu 9 krev   genetika   MeSH
• receptory LDL krev   genetika   MeSH
• znalecký posudek metody   normy   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Familial hypercholesterolemia (FH) is most frequently caused by LDLR or APOB mutations. Therefore, the aim of our study was to examine the genetic background of Slovak patients suspected of FH. Patients with clinical suspicion of FH (235 unrelated probands and 124 family relatives) were recruited throughout Slovakia during the years 2011-2015. The order of DNA analyses in probands was as follows: 1. APOB mutation p.Arg3527Gln by real-time PCR method, 2. direct sequencing of the LDLR gene 3. MLPA analysis of the LDLR gene. We have identified 14 probands and 2 relatives with an APOB mutation p.Arg3527Gln, and 89 probands and 75 relatives with 54 different LDLR mutations. Nine of LDLR mutations were novel (i.e. p.Asp90Glu, c.314-2A>G, p.Asp136Tyr, p.Ser177Pro, p.Lys225_Glu228delinsCysLys, p.Gly478Glu, p.Gly675Trpfs*42, p.Leu680Pro, p.Thr832Argfs*3). This is the first study on molecular genetics of FH in Slovakia encompassing the analysis of whole LDLR gene. Genetic etiology of FH was confirmed in 103 probands (43.8 %). Out of them, 86.4 % of probands carried the LDLR gene mutation and remaining 13.6 % probands carried the p.Arg3527Gln APOB mutation.

• MeSH
• dospělí MeSH
• hyperlipoproteinemie typ II diagnóza   epidemiologie   genetika   MeSH
• kvantitativní polymerázová řetězová reakce metody   MeSH
• lidé MeSH
• mladý dospělý MeSH
• receptory LDL genetika   MeSH
• statistika jako téma metody   MeSH
• zdravotnické přehledy * metody   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Slovenská republika epidemiologie   MeSH

Autosomal dominant hypercholesterolemia (ADH), more known as familial hypercholesterolemia (FH), is a lipid metabolism disorder characterized by an elevation in low-density lipoprotein cholesterol (LDL-C) and increased risk for cardiovascular disease. In this study, we assessed a spectrum of mutations causing ADH in 3914 unrelated Czech patients with clinical diagnosis of hypercholesterolemia. Samples have been collected within the framework of the MedPed project running in the Czech Republic since 1998. So far we have found 432 patients (11.0 %) with the APOB gene mutation p.(Arg3527Gln) and 864 patients (22.1 %) with the LDLR gene mutation. In 864 probands carrying the LDLR gene mutation, 182 unique allelic variants were detected. We have identified 14 patients homozygous for mutations in the LDLR or APOB genes. We performed function analyses of p.(Leu15Pro) and p.(Gly20Arg) sequence variations.

• MeSH
• apolipoprotein B-100 genetika   MeSH
• genetická variace genetika   MeSH
• genetické pozadí * MeSH
• hyperlipoproteinemie typ II krev   epidemiologie   genetika   MeSH
• LDL-cholesterol krev   genetika   MeSH
• lidé MeSH
• receptory LDL genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Geografické názvy
• Česká republika MeSH

Mutations in human genes can be responsible for inherited genetic disorders and cancer. Mutations can arise due to environmental factors or spontaneously. It has been shown that certain DNA sequences are more prone to mutate. These sites are termed hotspots and exhibit a higher mutation frequency than expected by chance. In contrast, DNA sequences with lower mutation frequencies than expected by chance are termed coldspots. Mutation hotspots are usually derived from a mutation spectrum, which reflects particular population where an effect of a common ancestor plays a role. To detect coldspots/hotspots unaffected by population bias, we analysed the presence of germline mutations obtained from HGMD database in the 5-nucleotide segments repeatedly occurring in genes associated with common inherited disorders, in particular, the PAH, LDLR, CFTR, F8, and F9 genes. Statistically significant sequences (mutational motifs) rarely associated with mutations (coldspots) and frequently associated with mutations (hotspots) exhibited characteristic sequence patterns, e.g. coldspots contained purine tract while hotspots showed alternating purine-pyrimidine bases, often with the presence of CpG dinucleotide. Using molecular dynamics simulations and free energy calculations, we analysed the global bending properties of two selected coldspots and two hotspots with a G/T mismatch. We observed that the coldspots were inherently more flexible than the hotspots. We assume that this property might be critical for effective mismatch repair as DNA with a mutation recognized by MutSα protein is noticeably bent.

• MeSH
• DNA chemie   genetika   MeSH
• faktor VIII genetika   MeSH
• genetická predispozice k nemoci MeSH
• konformace nukleové kyseliny MeSH
• lidé MeSH
• molekulární modely MeSH
• nukleotidové motivy MeSH
• protein CFTR genetika   MeSH
• receptory LDL genetika   MeSH
• simulace molekulární dynamiky MeSH
• zárodečné mutace * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The low density lipoprotein receptor (LDLR) is a transmembrane protein that plays a key role in cholesterol metabolism. It contains 860 amino acids including a 21 amino acid long signal sequence, which directs the protein into the endoplasmic reticulum. Mutations in the LDLR gene lead to cholesterol accumulation in the plasma and results in familial hypercholesterolemia (FH). Knowledge of the impact of a mutation on the LDLR protein structure and function is very important for the diagnosis and management of FH. Unfortunately, for a large proportion of mutations this information is still missing. In this study, we focused on the LDLR signal sequence and carried out functional and in silico analyses of two sequence changes, p.(Gly20Arg) and p.(Leu15Pro), localized in this part of the LDLR. Our results revealed that the p.(Gly20Arg) change, previously described as disease causing, has no detrimental effect on protein expression or LDL particle binding. In silico analysis supports this observation, showing that both the wt and p.(Gly20Arg) signal sequences adopt an expected α-helix structure. In contrast, the mutation p.(Leu15Pro) is not associated with functional protein expression and exhibits a structure with disrupted a α-helical arrangement in the signal sequence, which most likely affects protein folding in the endoplasmic reticulum.

• MeSH
• arginin chemie   MeSH
• CHO buňky MeSH
• Cricetulus MeSH
• endoplazmatické retikulum metabolismus   MeSH
• glycin chemie   MeSH
• heterozygot MeSH
• hyperlipoproteinemie typ II krev   genetika   MeSH
• konfokální mikroskopie MeSH
• křečci praví MeSH
• leucin chemie   MeSH
• lidé MeSH
• mutace MeSH
• prolin chemie   MeSH
• proteiny - lokalizační signály genetika   MeSH
• receptory LDL genetika   metabolismus   MeSH
• rodokmen MeSH
• sbalování proteinů MeSH
• sekundární struktura proteinů MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH