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
This 2023 statement updates clinical guidance for homozygous familial hypercholesterolaemia (HoFH), explains the genetic complexity, and provides pragmatic recommendations to address inequities in HoFH care worldwide. Key strengths include updated criteria for the clinical diagnosis of HoFH and the recommendation to prioritize phenotypic features over genotype. Thus, a low-density lipoprotein cholesterol (LDL-C) >10 mmol/L (>400 mg/dL) is suggestive of HoFH and warrants further evaluation. The statement also provides state-of-the art discussion and guidance to clinicians for interpreting the results of genetic testing and for family planning and pregnancy. Therapeutic decisions are based on the LDL-C level. Combination LDL-C-lowering therapy-both pharmacologic intervention and lipoprotein apheresis (LA)-is foundational. Addition of novel, efficacious therapies (i.e. inhibitors of proprotein convertase subtilisin/kexin type 9, followed by evinacumab and/or lomitapide) offers potential to attain LDL-C goal or reduce the need for LA. To improve HoFH care around the world, the statement recommends the creation of national screening programmes, education to improve awareness, and management guidelines that account for the local realities of care, including access to specialist centres, treatments, and cost. This updated statement provides guidance that is crucial to early diagnosis, better care, and improved cardiovascular health for patients with HoFH worldwide.
- MeSH
- anticholesteremika * terapeutické užití MeSH
- ateroskleróza * farmakoterapie MeSH
- homozygot MeSH
- homozygotní familiární hypercholesterolemie * MeSH
- hyperlipoproteinemie typ II * diagnóza genetika terapie MeSH
- LDL-cholesterol genetika MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Lipoprotein apheresis (LA) is a therapeutic option for patients with severe hypercholesterolemia who have persistently elevated LDL-C levels despite attempts at drug therapy. MicroRNAs (miRNAs), important posttranscriptional gene regulators, are involved in the pathogenesis of atherosclerosis. Our study aimed to monitor the dynamics of twenty preselected circulating miRNAs in patients under long-term apheresis treatment. Plasma samples from 12 FH patients (men = 50%, age = 55.3 ± 12.2 years; mean LA overall treatment time = 13.1 ± 7.8 years) were collected before each apheresis therapy every sixth month over the course of four years of treatment. Eight complete follow-up (FU) samples were measured in each patient. Dynamic changes in the relative quantity of 6 miRNAs (miR-92a, miR-21, miR-126, miR-122, miR-26a, and miR-185; all p < 0.04) during FU were identified. Overall apheresis treatment time influenced circulating miR-146a levels (p < 0.04). In LDLR mutation homozygotes (N = 5), compared to heterozygotes (N = 7), we found higher plasma levels of miR-181, miR-126, miR-155, and miR-92a (all p < 0.03). Treatment with PCSK9 inhibitors (N = 6) affected the plasma levels of 7 miRNAs (miR-126, miR-122, miR-26a, miR-155, miR-125a, miR-92a, and miR-27a; all p < 0.04). Long-term monitoring has shown that LA in patients with severe familial hypercholesterolemia influences plasma circulating miRNAs involved in endothelial dysfunction, cholesterol homeostasis, inflammation, and plaque development. The longer the treatment using LA, the better the miRNA milieu depicting the potential cardiovascular risk.
- MeSH
- cirkulující mikroRNA * genetika MeSH
- dospělí MeSH
- hyperlipoproteinemie typ II * genetika terapie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mikro RNA * genetika MeSH
- proproteinkonvertasa subtilisin/kexin typu 9 genetika MeSH
- senioři MeSH
- separace krevních složek * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- časná diagnóza MeSH
- hyperlipoproteinemie typ II * diagnóza genetika prevence a kontrola MeSH
- lidé MeSH
- novorozenec MeSH
- novorozenecký screening metody MeSH
- Check Tag
- lidé MeSH
- novorozenec MeSH
- Publikační typ
- rozhovory MeSH
PURPOSE: In 2015, the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) published consensus standardized guidelines for sequence-level variant classification in Mendelian disorders. To increase accuracy and consistency, the Clinical Genome Resource Familial Hypercholesterolemia (FH) Variant Curation Expert Panel was tasked with optimizing the existing ACMG/AMP framework for disease-specific classification in FH. In this study, we provide consensus recommendations for the most common FH-associated gene, LDLR, where >2300 unique FH-associated variants have been identified. METHODS: The multidisciplinary FH Variant Curation Expert Panel met in person and through frequent emails and conference calls to develop LDLR-specific modifications of ACMG/AMP guidelines. Through iteration, pilot testing, debate, and commentary, consensus among experts was reached. RESULTS: The consensus LDLR variant modifications to existing ACMG/AMP guidelines include (1) alteration of population frequency thresholds, (2) delineation of loss-of-function variant types, (3) functional study criteria specifications, (4) cosegregation criteria specifications, and (5) specific use and thresholds for in silico prediction tools, among others. CONCLUSION: Establishment of these guidelines as the new standard in the clinical laboratory setting will result in a more evidence-based, harmonized method for LDLR variant classification worldwide, thereby improving the care of patients with FH.
- MeSH
- genetická variace genetika MeSH
- genetické testování metody MeSH
- genom lidský * genetika MeSH
- genomika metody MeSH
- hyperlipoproteinemie typ II * genetika MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- MeSH
- anticholesteremika farmakologie terapeutické užití MeSH
- dítě MeSH
- dyslipidemie * diagnóza genetika terapie MeSH
- genetická terapie MeSH
- hyperlipoproteinemie typ II * diagnóza genetika terapie MeSH
- lidé MeSH
- screeningové diagnostické programy MeSH
- statiny farmakologie terapeutické užití MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- novinové články MeSH
- MeSH
- diferenciální diagnóza MeSH
- hyperlipoproteinemie typ II * farmakoterapie genetika krev MeSH
- lidé MeSH
- lipoprotein (a) analýza genetika škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- novinové články MeSH
Familial hypercholesterolaemia (FH) is under-recognized and under-treated in Europe leading to significantly higher risk for premature heart disease in those affected. As treatment beginning early in life is highly effective in preventing heart disease and cost-effective in these patients, screening for FH is crucial. It has therefore now been recognized by the European Commission Public Health Best Practice Portal as an effective strategy. Model programmes exist in Europe to identify young individuals with FH, which are based on cascade screening of first-degree relatives of affected individuals, universal screening for high cholesterol, opportunistic screening of high-risk individuals, or a combination of the above approaches. Recommendations presented herein to improve identification of FH emphasize that every country should have an FH screening programme. These programmes should be adapted from existing strategies to best fit the individual country's healthcare system, governments should provide financial support for these programmes and related care, and further research to optimize care and implementations should be conducted.
- MeSH
- dítě MeSH
- genetické testování MeSH
- hyperlipoproteinemie typ II * diagnóza epidemiologie genetika MeSH
- LDL-cholesterol MeSH
- lidé MeSH
- nemoci srdce * MeSH
- plošný screening MeSH
- rizikové faktory MeSH
- veřejná politika MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa 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.
