scholarly journals Molecular Screening of Familial Hypercholesterolemia in the Icelandic Population

2018 ◽  
Author(s):  
Greg Kellogg ◽  
Bolli Thorsson ◽  
Ying Cai ◽  
Robert Wisotzkey ◽  
Andrew Pollock ◽  
...  
Keyword(s):  
Genetic Testing ◽  
Familial Hypercholesterolemia ◽  
Population Based ◽  
Lipid Lowering ◽  
Monogenic Disease ◽  
Loss Of Function ◽  
Cholesterol Levels ◽  
Icelandic Population ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

AbstractFamilial hypercholesterolemia (FH) is a monogenic disease characterized by a lifelong exposure to high LDL-C levels that can lead to early onset coronary heart disease (CHD). The main causes of FH identified to date include loss-of-function mutations in LDLR or APOB, or gain-of-function mutations in PCSK9. Early diagnosis and genetic testing of FH suspects is critical for improved prognosis of affected individuals as lipid lowering treatments are effective in preventing CHD related morbidity and mortality. In the present manuscript, we developed a comprehensive next generation sequencing (NGS) panel which we applied on two different resources of FH in the Icelandic population: 62 subjects from 23 FH families with known or unknown culprit mutations, and a population-based sampling of 315 subjects selected for total cholesterol levels above the 95th percentile cut-point. The application of the NGS panel revealed significant diagnostic yields in identifying pathogenic LDLR mutations in both family and population-based genetic testing.

scholarly journals FAMILIAL HYPERCHOLESTEROLEMIA: DIAGNOSTIC ISSUES AND THERAPEUTIC POSSIBILITIES

2019 ◽  
Vol 26 (1) ◽  
pp. 175-186
Author(s):  
Vitalii K. Zafiraki ◽  
Alim M. Namitokov ◽  
Elena D. Kosmacheva
Keyword(s):  
Familial Hypercholesterolemia ◽  
Conflict Of Interest ◽  
Screening Program ◽  
Genetic Defect ◽  
Clinical Manifestations ◽  
Density Lipoprotein ◽  
Premature Death ◽  
Lipid Lowering ◽  
Monogenic Disease ◽  
Lipid Lowering Therapy

Familial hypercholesterolemia (FHC) is a common monogenic disease that occurs with a frequency of ~1:250 and is characterised by a high content of low-density lipoprotein (LDL) in the blood. This disease leads to the early development of atherosclerotic cardiovascular diseases (ACVD). Although the screening and diagnostics issues concerned with FHC are well developed and the modern lipid-lowering therapy can significantly improve the prognosis, the detectability of this disease remains extremely low. In recent years, the concept of FHC has undergone significant changes under the influence of large epidemiological studies, including verification of the FHC diagnosis using genetic tests. The article is aimed at discussing the clinical manifestations of FHC, as well as modern medical and extracorporal approaches to its treatment.Conclusion.Until the advent of modern lipid-lowering drugs, FHC had remained to be a disease with a poor prognosis due to early ACVD and the associated premature death. Today, the diseases is amenable to successful treatment, which, though not eliminating the genetic defect, allows almost the same life duration as in the general population to be achieved. However, all the possibilities of modern approaches to the treatment of this serious disease can be realized provided that a state-level screening program for such patients has been implemented.Conflict of interest: the authors declare no conflict of interest.

scholarly journals GUCY2D Gene Loss-of-Function Mutations Responsible for Leber Congenital Amaurosis 1

2019 ◽  
Author(s):  
Feng Xue ◽  
Tianying Wei ◽  
Junhui Sun ◽  
Yuqin Luo ◽  
Yanan Huo ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Guanylate Cyclase ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Loss Of Function ◽  
Wild Type ◽  
Leber Congenital Amaurosis ◽  
Cellular Location ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

Abstract Background: Leber congenital amaurosis (LCA) is a group of severe congenital neurodegenerative diseases. Variants in guanylate cyclase 2D (GUCY2D), which encoded guanylate cyclase protein (ROS-GC1) associate with LCA1, accounting for 6–21% of all LCA cases. Methods: In this study, one family with LCA1 was recruited from China. A combination of next-generation sequencing (NGS) and Sanger sequencing was used for disease-causing mutations screening. Additionally, immunohistochemistry and HPLC-coupled tandem mass-spectrometry (HPLC-MS/MS) were used to confirm the cellular location and catalytic activity of ROS-GC1 mutants, respectively. Results: We found three novel mutations (c.139_139delC, c.835G>A and c.2783G>A) in GUCY2D gene. The results showed that mutation c.139_139delC results in a truncated protein and destroys the structure of ROS-GC1 protein. Mutations c.835G>A and c.2783G>A exert no effects on cellular location, whereas significantly reduce the catalytic activity of ROS-GC1. Conclusions: Our findings highlight the clinical range of LCA. Moreover we used HPLC-MS/MS to analyze the concentration of 3', 5'-cyclic guanosine monophosphate (cGMP), suggesting that HPLC-MS/MS can be an effective alternative method to evaluate the catalytic activity of wild type (wt) and mutant ROS-GC1.

P–551 Blastocyst cohort size is not associated with embryo aneuploidy: comprehensive multi-centre data from current preimplantation genetic testing cycles

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
R Vassena ◽  
A Lorenzon ◽  
A L Lopes ◽  
D Sakkas ◽  
A Korkidakis ◽  
...  
Keyword(s):  
Genetic Testing ◽  
Maternal Age ◽  
Age Groups ◽  
Ovarian Response ◽  
Cohort Size ◽  
Preimplantation Genetic Testing ◽  
Indirect Measure ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing ◽  
Euploid Embryo

Abstract Study question Does blastocyst cohort size impact aneuploidy rates, evaluated by next generation sequencing (NGS)? Summary answer Embryo aneuploidy rates were independent of blastocyst cohort size across all patient ages. What is known already The effects of ovarian response on oocyte and embryo quality remain controversial. Several studies have proposed that a high response to ovarian stimulation may negatively impact oocyte competence. Alternatively, irrespective of maternal age, a poor ovarian response may potentially compromise embryo quality. Using blastocyst cohort size as an indirect measure of ovarian response, previous studies applying array comparative genomic hybridisation (aCGH) have demonstrated that the number of embryos available for biopsy does not impact embryo aneuploidy rates. Nevertheless, these findings remain to be confirmed in a comprehensive cohort, using current approaches for preimplantation genetic testing for aneuploidies (PGT-A). Study design, size, duration Retrospective, international, cohort study of 3998 patients from 16 clinics undergoing PGT-A from 2016–2020. We evaluated 11665 blastocysts, tested using trophectoderm (TE) biopsy and next generation sequencing (NGS). To eliminate bias of multiple treatments, we considered only the first PGT-A cycle for all patients. Both autologous and donation cycles were included in the analysis. Cycles were excluded if they utilised preimplantation genetic testing for monogenic disorders (PGT-M) or preimplantation genetic testing for structural rearrangements (PGT-SR). Participants/materials, setting, methods We evaluated aneuploidy and mosaicism rates, as well as the proportion of patients who had at least one euploid embryo suitable for transfer. Findings were stratified according to SART-defined maternal age groups, <35 (n = 698/2622 patients/blastocysts), 35–37 (n = 988/3141 patients/blastoycsts), 38–40 (n = 1447/3939 patients/blastocysts), 41–42 (653/1562 patients/blastocysts) and >42 (212/401 patients/blastocysts) and blastoycst cohort size (1–2, 3–5, 6–9 and 10 or more biopsied blastocysts). Main results and the role of chance The mean maternal age was 37.0±3.7. The overall embryo aneuploidy rate was 50.6% (5904/11665), while mosaicism was established in 4.0% (469/11665) of blastocysts. As expected, the proportion of aneuploid embryos increased steadily with advancing maternal age (31.8%, 41.5%, 58.4%, 71.2%, 87.8%; p < 0.0001), while mosaicism rates did not vary significantly (p = 0.2). Within each age group, we observed no association between the number of blastocysts biopsied and aneuploidy or mosaicism rates. However, as previously suggested, the chance of having at least one euploid embryo increased linearly with the number of embryos biopsied. We observed that young patients (<35) with 1–2 blastocysts had a 70.4% of having at least one embryo suitable for transfer, which increased to 96.4% and 99.2% with 3–5 and 6–9 blastocysts, respectively. Similar trends were observed in the 36–38 and 39–40 age groups. Patients in the 40–41 age group had a significantly lower chance of having a suitable embryo for transfer. Nevertheless, the chance increased from 27.2% with 1–2 embryos to 61.2% with 3–5 blastocysts. Patients with >10 embryos had at least one euploid embryo in 100% of cases, across all ages. Albeit, the numbers of patients within this category was low, and decreased significantly with advancing maternal age. Limitations, reasons for caution While blastocyst cohort size is considered to be an indirect measure of ovarian reserve, the number of oocytes retrieved was not evaluated. Our study only included the first PGT-A cycle for all patients. Subsequent, alterations in stimulation protocols may have resulted in an improved response in some patients. Wider implications of the findings: The comprehensive nature of the study, based on current PGT-A approaches and a large number of cycles across 16 centres increases clinical confidence in the notion that ovarian response is independent of embryo aneuploidy. Importantly, our findings may serve as a valuable clinical resource to guide patient counselling strategies. Trial registration number NA

Cross-Sectional Study to Estimate the Prevalence of Familial Hypercholesterolemia in Selected Regions of the Russian Federation: Relevance, Design of the Study and Initial Characteristics of the Participants

2020 ◽  
Vol 16 (1) ◽  
pp. 24-32
Author(s):  
A. N. Meshkov ◽  
A. I. Ershova ◽  
S. A. Shalnova ◽  
A. S. Alieva ◽  
S. S. Bazhan ◽  
...  
Keyword(s):  
Genetic Testing ◽  
Cardiovascular Diseases ◽  
Familial Hypercholesterolemia ◽  
Russian Federation ◽  
Regional Differences ◽  
Lipid Lowering ◽  
Lipid Lowering Therapy ◽  
Lowering Therapy ◽  
History Of ◽  
The Russian Federation

Aim. To study the prevalence of familial hypercholesterolemia (FH), the characteristics of the clinical features and treatment of the disease in selected regions of the Russian Federation, this article describes the design and initial characteristics of patients included in the study.Material and methods. The study participants were selected among those included in the study “Epidemiology of cardiovascular risk factors and diseases in the regions of the Russian Federation” (ESSE-RF) in different regions of the Russian Federation. The study included individuals with lowdensity lipoprotein cholesterol (LDL-C) levels >4.9 mmol/l or LDL-C levels >1.8 mmol/l, but ≤4.9 mmol/l during statin therapy, according to the data obtained in the ESSE-RF study. These persons are invited for examination and questioning by experts in the field of FH diagnostics. On the basis of the survey data and provided medical documentation, the following information is collected: age, sex, smoking status, presence of hypertension, history of coronary artery disease, stroke, atherosclerosis of cerebral and peripheral arteries, LDL-C level, type, volume and duration of lipid-lowering therapy throughout life, presence and dates of secondary causes of hyperlipidemia, information about the family history of development of early cardiovascular diseases and atherosclerotic diseases, increased levels of LDL-C in relatives of the 1st and 2nd degree of kinship. All patients are examined for the presence of tendon xanthomas (Achilles, metacarpal, elbow, knee tendons) and Corneal arcus. During the visit, blood is taken for subsequent biobanking, measurement of current blood lipid levels, elimination of secondary forms of hypercholesterolemia (for subsequent determination of liver enzymes, thyroid stimulating hormone) and genetic testing. The diagnosis of FH is based on Dutch Lipid Clinical Network Criteria (DLCN). Besides, all participants in the study are tested for compliance with the diagnosis of FH according to Simon Broome criteria. All patients with a definite or probable diagnosis of FH according to DLCN or Simon Broome criteria are subjected to ultrasound examination of carotid, femoral arteries and heart and molecular genetic testing for LDLR, APOB and PCSK9 gene variants.Results. Out of 16 360 participants of the ESSE-RF study in 10 regions, 1787 people (10,9%) met the criteria for inclusion in this study. Among them, men accounted for 35.4%, of which 1150 (7%) patients had a LDL-C level >4.9 mmol/l and 637 (3,9%) had a LDL-C level from 1,81 mmol/l to 4.9 mmol/l during lipid-lowering therapy. When compared to the original cohorts of participants from the 10 regions as compared to 3 previously surveyed regions and selected sub-groups within these cohorts we observed significant differences in several parameters such as age, total cholesterol level, triglycerides, LDL-C, the frequency of cardiovascular diseases, that may indicate regional differences in FH prevalence.Conclusion. The analysis of clinical data of the participants of the ESSE-RF study shows that more than 10% of individuals require an additional examination to verify the FH diagnosis, and regional differences in the FH prevalence are possible.

scholarly journals Next-generation sequencing to confirm clinical familial hypercholesterolemia

2020 ◽  
pp. 204748732094299
Author(s):  
Laurens F Reeskamp ◽  
Tycho R Tromp ◽  
Joep C Defesche ◽  
Aldo Grefhorst ◽  
Erik SG Stroes ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Familial Hypercholesterolemia ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Pathogenic Variant ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol ◽  
The Past ◽  
Cholesterol Levels ◽  
Generation Sequencing

Background Familial hypercholesterolemia is characterised by high low-density lipoprotein-cholesterol levels and is caused by a pathogenic variant in LDLR, APOB or PCSK9. We investigated which proportion of suspected familial hypercholesterolemia patients was genetically confirmed, and whether this has changed over the past 20 years in The Netherlands. Methods Targeted next-generation sequencing of 27 genes involved in lipid metabolism was performed in patients with low-density lipoprotein-cholesterol levels greater than 5 mmol/L who were referred to our centre between May 2016 and July 2018. The proportion of patients carrying likely pathogenic or pathogenic variants in LDLR, APOB or PCSK9, or the minor familial hypercholesterolemia genes LDLRAP1, ABCG5, ABCG8, LIPA and APOE were investigated. This was compared with the yield of Sanger sequencing between 1999 and 2016. Results A total of 227 out of the 1528 referred patients (14.9%) were heterozygous carriers of a pathogenic variant in LDLR (80.2%), APOB (14.5%) or PCSK9 (5.3%). More than 50% of patients with a Dutch Lipid Clinic Network score of ‘probable’ or ‘definite’ familial hypercholesterolemia were familial hypercholesterolemia mutation-positive; 4.8% of the familial hypercholesterolemia mutation-negative patients carried a variant in one of the minor familial hypercholesterolemia genes. The mutation detection rate has decreased over the past two decades, especially in younger patients in which it dropped from 45% in 1999 to 30% in 2018. Conclusions A rare pathogenic variant in LDLR, APOB or PCSK9 was identified in 14.9% of suspected familial hypercholesterolemia patients and this rate has decreased in the past two decades. Stringent use of clinical criteria algorithms is warranted to increase this yield. Variants in the minor familial hypercholesterolemia genes provide a possible explanation for the familial hypercholesterolemia phenotype in a minority of patients.

scholarly journals Management of Familial Hypercholesterolemia: Current Status and Future Perspectives

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
David T W Lui ◽  
Alan C H Lee ◽  
Kathryn C B Tan
Keyword(s):  
Familial Hypercholesterolemia ◽  
Ldl Cholesterol ◽  
Genetic Disorder ◽  
Lipid Lowering ◽  
Current Status ◽  
Atherosclerotic Cardiovascular Disease ◽  
Inadequate Response ◽  
Cholesterol Lowering ◽  
Cholesterol Levels ◽  
Pubmed Database

Abstract Familial hypercholesterolemia (FH) is the most common monogenic disorder associated with premature atherosclerotic cardiovascular disease. Early diagnosis and effective treatment can significantly improve prognosis. Recent advances in the field of lipid metabolism have shed light on the molecular defects in FH and new therapeutic options have emerged. A search of PubMed database up to March 2020 was performed for this review using the following keywords: “familial hypercholesterolemia,” “diagnosis,” “management,” “guideline,” “consensus,” “genetics,” “screening,” “lipid lowering agents.” The prevalence rate of heterozygous FH is approximately 1 in 200 to 250 and FH is underdiagnosed and undertreated in many parts of the world. Diagnostic criteria have been developed to aid the clinical diagnosis of FH. Genetic testing is now available but not widely used. Cascade screening is recommended to identify affected family members, and the benefits of early interventions are clear. Treatment strategy and target is currently based on low-density lipoprotein (LDL) cholesterol levels as the prognosis of FH largely depends on the magnitude of LDL cholesterol-lowering that can be achieved by lipid-lowering therapies. Statins with or without ezetimibe are the mainstay of treatment and are cost-effective. Addition of newer medications like PCSK9 inhibitors is able to further lower LDL cholesterol levels substantially, but the cost is high. Lipoprotein apheresis is indicated in homozygous FH or severe heterozygous FH patients with inadequate response to cholesterol-lowering therapies. In conclusion, FH is a common, treatable genetic disorder, and although our understanding of this disease has improved, many challenges still remain for its optimal management.

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