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The present work aims to determine the genetic cause (monogenic or polygenic) of hypercholesterolemia in clinical FH patients. N/A

Aims and study samples: Estimate cardiovascular disease (CVD) risk; What are the lipid-lowering therapy (LLT) strategies; How many are reaching LDL-C targets … in Familial Hypercholesterolemia (FH) patients and in the Portuguese general population. N/A

The American College of Medical Genetics and Genomics guidelines for variant classification are composed of several evidence criteria that, when combined, lead to a 5-tier pathogenicity variant classification. Several criteria rely on case-level data from patients, relatives, or controls with or without a particular variant of interest. (...) N/A

Familial Hypercholesterolemia (FH) is a common autosomal genetic disorder (1/250-1/500 worldwide). Clinically these patients present with high levels of cholesterol since birth, family history of hypercholesterolemia and premature cardiovascular disease. Formal genetic diagnosis includes the study of 3 genes: LDLR, APOB, PCSK9. Recently, other 5 genes have been associated with the FH phenotype (LDLRAP1, APOE, LIPA, ABCG5/8) since pathogenic variants have been identified in clinical FH patients. N/A

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. © 2021 Elsevier B.V.

Familial Hypercholesterolemia (FH): - Lipid metabolism autosomal dominant condition; - Elevated low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) values since childhood → increased risk of atherosclerotic cardiovascular disease; - High heterozygote prevalence (1/250-1/500); Homozygous rare (1/ 300 000- 1/ 1 000 000); - Caused by pathogenic variants in LDLR (>90%), APOB (5- 10%) and PCSK9 (1-3%) genes; -Marked increase in FH variants submitted to ClinVar; -45% of variants were classified with more than one method and 466 variants submitted with potential clinical significance had conflicting or no classifications. N/A

Introduction: Familial Hypercholesterolemia (FH) is a common autosomal genetic disorder (1/250-1/500 worldwide); FH patients have high levels of cholesterol since birth with a family history of hypercholesterolemia and premature cardiovascular disease; Genetic diagnosis results from the study of 3 genes: LDLR, APOB, PCSK9; Recently, 5 genes have been associated with FH phenotype (LDLRAP1, APOE, LIPA, ABCG5/8) since pathogenic variants in those genes have been identified in clinical FH patients. N/A

Prémio do melhor caso clínico Aim: To determine the prevalence of statin pharmacogenetic relevant genotypes in the Portuguese population. N/A

Background and aims: For children with heterozygous familial hypercholesterolaemia (HeFH), European guidelines recommend consideration of statin therapy by age 8–10 years for those with a low density lipoprotein cholesterol (LDL-C) >3.5 mmol/l, and dietary and lifestyle advice. Here we compare the characteristics and lipid levels in HeFH children from Norway, UK, Netherlands, Belgium, Czech Republic, Austria, Portugal and Greece. Methods: Fully-anonymized data were analysed at the London centre. Differences in registration and on treatment characteristics were compared by standard statistical tests. Results: Data was obtained from 3064 children. The median age at diagnosis differed significantly between countries (range 3–11 years) reflecting differences in diagnostic strategies. Mean (SD) LDL-C at diagnosis was 5.70 (±1.4) mmol/l, with 88% having LDL-C>4.0 mmol/l. The proportion of children older than 10 years at follow-up who were receiving statins varied significantly (99% in Greece, 56% in UK), as did the proportion taking Ezetimibe (0% in UK, 78% in Greece). Overall, treatment reduced LDL-C by between 28 and 57%, however, in those >10 years, 23% of on-treatment children still had LDL-C>3.5 mmol/l and 66% of those not on a statin had LDL-C>3.5 mmol/l. Conclusions: The age of HeFH diagnosis in children varies significantly across 8 countries, as does the proportion of those >10 years being treated with statin and/or ezetimibe. Approximately a quarter of the treated children and almost three quarters of the untreated children older than 10 years still have LDL-C concentrations over 3.5 mmol/l. These data suggest that many children with FH are not receiving the full potential benefit of early identification and appropriate lipid-lowering treatment according to recommendations. © 2019 The Authors

Familial Hypercholesterolaemia (FH) is a monogenic disorder characterised by high 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. Methods and Results 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 PCR 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. Cibelle Mariano was supported by a PhD student grant [SFRH/BD/52494/2014]. Marta Futema is supported by the Fondation Leducq Transatlantic Networks of Excellence Program grant (no 14 CVD03). The work of Marilia Antunes is partially funded by UID/MAT/000016/2019. SEH acknowledges funding from the British Heart Foundation grant (BHF PG08/008) and from the NIHR UCLH BRC. MB acknowledges funding from Science and Technology Foundation (PIC/IC/83020/2007) (PIC/IC/83333/2007) for the e_COR and Portuguese FH Study and from Portuguese Cardiology Society for the Portuguese FH Study. info:eu-repo/semantics/publishedVersion

Familial Hypercholesterolemia (FH) patients have na increased cardiovascular risk due to high TC or LDL-C levels. Lp(a) chemical structure is similar to LDL and elevated Lp(a) is considered an independent risk factor for cardiovascular disease (CVD). Recently, it has been described that in patients with high Lp(a), the Lp(a)-C can contribute up to 25% to 50% of all LDL-C. Two LPA variants (rs3798220 and rs10455872) were strongly associated with high Lp(a) levels and increased risk of CVD. In the present work we aim to determine how elevated Lp(a) concentrations and LPA genotype may contribute to clinical phenotype of FH. N/A

Familial hypercholesterolaemia is an autosomal dominant disorder of lipid metabolism characterized by elevated levels of LDL-C and increased cardiovascular risk. Although the disorder can be diagnosed based on established clinical criteria, only the genetic diagnosis confirms the clinical suspicion. N/A

Background: Clinically, Familial Hypercholesterolaemia (FH) is characterized by high plasma concentrations of total and LDL cholesterol from birth, leading to premature atherosclerosis and coronary heart disease. Currently, the genetic diagnosis is made by finding a functional mutation in one of 3 genes: low-density lipoprotein receptor (LDLR ≈ 90-94%), apolipoprotein B (APOB ≈ 5-9%) and proprotein convertase subtilisin/kexin type 9 (PCSK9 ≈ 1-3%). Problem: Worldwide 50% of clinically diagnosed FH patients lack the identification of a causative mutation to explain their phenotype. Aim: Explore if rare genetic variants in genes involved in monogenic forms of dyslipidaemia can contribute to the FH phenotype. With thanks to the EAS for support in the form of a Young Investigator Fellowship. Rafael Graça acknowledges financial support from FCT (PD/BD/131427/2017). N/A

Familial Hypercholesterolaemia (FH) is a monogenic lipid disorder caused by mutations in LDLR, APOB, and PCSK9 genes. However, 50% of individuals with clinical diagnosis of FH do not have a mutation in one of these three genes, so other causes for their phenotype must exist. The FH phenotype has been associated recently to other monogenic disorders as lysosomal acid lipase deficiency (LALD) and sitosterolaemia or can have a polygenic origin. The aim of this work was to characterize the origin of the FH phenotype in a cohort of patients with clinical diagnosis of FH. Cibelle Mariano was funded by SFRH/BD/52494/2014. N/A

Homozygous Familial Hypercholesterolemia (HoFH) is a rare disorder, affecting 1 in 300,000 to 1,000,000 people in the general population. The Iberoamerican FH (IBAFH) network was constituted in 2013 with the main objectives to promote awareness and education on FH, and to improve and promote early diagnosis and treatment of the disorder in the network countries. In 2018, there are 8 countries (Argentina, Brazil, Chile, Colombia, Mexico, Portugal, Spain and Uruguay) belonging to the network representing 75% of region’s population. It is estimated that there are 600 to 1,800 HoFH in the Ibero-America, most of them not diagnosed and/or not treated adequately. The Iberoamerican community has an estimated population of 640 million inhabitants. The objective of this work is to describe molecular characteristics of HoFH diagnosis in Argentina, Brazil, Chile, Colombia, Mexico, Portugal, Spain, and Uruguay. N/A

Familial hypercholesterolemia (FH) is an autosomal dominant disorder associated with high levels of LDL-c and premature CHD (pCHD). Identification of FH in pediatric age is essential for a timely diagnosis and management. This study aims to highlight the importance of FH diagnosis in children. Abrantes LB. grants PTDC/SAU-SER/29180/2017 N/A

The Portuguese FH Study (PFHS) started in 1999. The aim of the PFHS is to identify the cause of dyslipidemia in patients with a clinical diagnosis of FH. To date, 452 pediatric patients were referred to us, 288 of which are index patients. The aim of this study was to analyse the lipid profile and molecular diagnosis of children recruited for the PFHS. Abrantes LB. acknowledges grant BioMolecular/09/2017 N/A