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Background: Inclisiran is a small interfering RNA molecule that reduces low-density lipoprotein cholesterol (LDL-C) by inhibition of proprotein convertase subtilisin/kexin type 9. This subcutaneous, twice-yearly administered agent has been shown to effectively and safely lower LDL-C in adult patients with established atherosclerotic cardiovascular disease, adults at high risk for atherosclerotic cardiovascular disease, as well as in adults with heterozygous familial hypercholesterolaemia. With the current, limited treatment options available to reach treatment goals in children with severe heterozygous familial hypercholesterolaemia, homozygous familial hypercholesterolaemia, or statin intolerance, inclisiran could be a valuable new therapeutic option., Objectives: The objective of these ongoing studies is to investigate the efficacy, safety, and tolerability of inclisiran in adolescents diagnosed with homozygous familial hypercholesterolaemia (ORION-13) or heterozygous familial hypercholesterolaemia (ORION-16)., Study Design: ORION-13 and ORION-16 are both two-part (1-year double-blind inclisiran vs. placebo/1 year open-label inclisiran) multicentre trials including adolescents aged 12 to <18 years diagnosed with familial hypercholesterolaemia. ORION-13 will include ∼12 participants diagnosed with homozygous familial hypercholesterolaemia and ORION-16 will include ∼150 participants diagnosed with heterozygous familial hypercholesteroleamia. The primary endpoint is the percentage change in LDL-C from baseline to Day 330. Secondary efficacy and safety endpoints include changes in other lipid parameters and treatment-emergent adverse events as well as laboratory parameters and vital signs. Exploratory endpoints include individual responsiveness of the participants and change in LDL-C according to the type of underlying causal mutation., Clinical Trial Registration: https://www.clinicaltrials.gov/. Unique identifier: NCT04659863 (ORION-13) and NCT04652726 (ORION-16)., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2022. For permissions, please email: journals.permissions@oup.com.)

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., (© The Author(s) 2020. Published by Oxford University Press on behalf of the European Society of Cardiology.)

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.

Familial hypercholesterolaemia (FH) is a common genetic cause of premature coronary heart disease (CHD). Globally, one baby is born with FH every minute. If diagnosed and treated early in childhood, individuals with FH can have normal life expectancy. This consensus paper aims to improve awareness of the need for early detection and management of FH children. Familial hypercholesterolaemia is diagnosed either on phenotypic criteria, i.e. an elevated low-density lipoprotein cholesterol (LDL-C) level plus a family history of elevated LDL-C, premature coronary artery disease and/or genetic diagnosis, or positive genetic testing. Childhood is the optimal period for discrimination between FH and non-FH using LDL-C screening. An LDL-C ≥5 mmol/L (190 mg/dL), or an LDL-C ≥4 mmol/L (160 mg/dL) with family history of premature CHD and/or high baseline cholesterol in one parent, make the phenotypic diagnosis. If a parent has a genetic defect, the LDL-C cut-off for the child is ≥3.5 mmol/L (130 mg/dL). We recommend cascade screening of families using a combined phenotypic and genotypic strategy. In children, testing is recommended from age 5 years, or earlier if homozygous FH is suspected. A healthy lifestyle and statin treatment (from age 8 to 10 years) are the cornerstones of management of heterozygous FH. Target LDL-C is <3.5 mmol/L (130 mg/dL) if >10 years, or ideally 50% reduction from baseline if 8-10 years, especially with very high LDL-C, elevated lipoprotein(a), a family history of premature CHD or other cardiovascular risk factors, balanced against the long-term risk of treatment side effects. Identifying FH early and optimally lowering LDL-C over the lifespan reduces cumulative LDL-C burden and offers health and socioeconomic benefits. To drive policy change for timely detection and management, we call for further studies in the young. Increased awareness, early identification, and optimal treatment from childhood are critical to adding decades of healthy life for children and adolescents with FH., (© The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: Homozygous autosomal dominant hypercholesterolaemia (hoADH), an orphan disease caused by mutations in low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), or proprotein convertase subtilisin-kexin type 9 (PCSK9), is characterized by elevated plasma low-density lipoprotein-cholesterol (LDL-C) levels and high risk for premature cardiovascular disease (CVD). The exact prevalence of molecularly defined hoADH is unknown. Therefore, we investigated the prevalence and phenotypical characteristics of this disease in an open society, i.e. the Netherlands., Methods and Results: The database of the nationwide ADH molecular diagnostic center was queried to identify all molecularly defined hoADH patients. Carriers of non-pathogenic mutations were excluded. Medical records were analysed for data regarding lipid levels and CVD events. Of 104,682 individuals screened for molecular defects, 49 were classified as hoADH (0.05%); 20 were true homozygotes, 25 were compound heterozygotes for LDLR mutations, and 4 were homozygous for APOB mutations. No bi-allelic PCSK9 mutation carriers were identified. Consequently, the prevalence of hoADH was estimated to be ∼1 : 300,000. Mean LDL-C levels prior to lipid-lowering treatment were 12.9 ± 5.1 mmol/L (range 4.4-21.5 mmol/L). Surprisingly, only 50% of the patients met the clinical criteria for hoADH (LDL-C >13.0 mmol/L); 29% of patients suffered from a CVD event., Conclusion: The prevalence of molecularly defined hoADH is much higher and the clinical phenotype is more variable than previously assumed. In light of the fact that novel therapies are, or will be registered for the treatment of hoADH patients, an uniform definition of hoADH either as a phenotypic or molecular entity is warranted in order to identify patients who are considered to be eligible for these novel agents., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

Aims: The first aim was to critically evaluate the extent to which familial hypercholesterolaemia (FH) is underdiagnosed and undertreated. The second aim was to provide guidance for screening and treatment of FH, in order to prevent coronary heart disease (CHD)., Methods and Results: Of the theoretical estimated prevalence of 1/500 for heterozygous FH, <1% are diagnosed in most countries. Recently, direct screening in a Northern European general population diagnosed approximately 1/200 with heterozygous FH. All reported studies document failure to achieve recommended LDL cholesterol targets in a large proportion of individuals with FH, and up to 13-fold increased risk of CHD. Based on prevalences between 1/500 and 1/200, between 14 and 34 million individuals worldwide have FH. We recommend that children, adults, and families should be screened for FH if a person or family member presents with FH, a plasma cholesterol level in an adult ≥8 mmol/L(≥310 mg/dL) or a child ≥6 mmol/L(≥230 mg/dL), premature CHD, tendon xanthomas, or sudden premature cardiac death. In FH, low-density lipoprotein cholesterol targets are <3.5 mmol/L(<135 mg/dL) for children, <2.5 mmol/L(<100 mg/dL) for adults, and <1.8 mmol/L(<70 mg/dL) for adults with known CHD or diabetes. In addition to lifestyle and dietary counselling, treatment priorities are (i) in children, statins, ezetimibe, and bile acid binding resins, and (ii) in adults, maximal potent statin dose, ezetimibe, and bile acid binding resins. Lipoprotein apheresis can be offered in homozygotes and in treatment-resistant heterozygotes with CHD., Conclusion: Owing to severe underdiagnosis and undertreatment of FH, there is an urgent worldwide need for diagnostic screening together with early and aggressive treatment of this extremely high-risk condition.

Aims: Recent genome-wide association studies suggest that IDOL (also known as MYLIP) contributes to variation in circulating levels of low-density lipoprotein cholesterol (LDL-C). IDOL, an E3-ubiquitin ligase, is a recently identified post-transcriptional regulator of LDLR abundance. Briefly, IDOL promotes degradation of the LDLR thereby limiting LDL uptake. Yet the exact role of IDOL in human lipoprotein metabolism is unclear. Therefore, this study aimed at identifying and functionally characterizing IDOL variants in the Dutch population and to assess their contribution to circulating levels of LDL-C., Methods and Results: We sequenced the IDOL coding region in 677 individuals with LDL-C above the 95th percentile adjusted for age and gender (high-LDL-C cohort) in which no mutations in the LDLR, APOB, and PCSK9 could be identified. In addition, IDOL was sequenced in 560 individuals with baseline LDL-C levels below the 20th percentile adjusted for age and gender (low-LDL-C cohort). We identified a total of 14 IDOL variants (5 synonymous, 8 non-synonymous, and 1 non-sense). Functional characterization of these variants demonstrated that the p.Arg266X variant represents a complete loss of IDOL function unable to promote ubiquitylation and subsequent degradation of the LDLR. Consistent with loss of IDOL function, this variant was identified in individuals with low circulating LDL-C., Conclusion: Our results support the notion that IDOL contributes to variation in circulating levels of LDL-C. Strategies to inhibit IDOL activity may therefore provide a novel therapeutic venue to treating dyslipidaemia.

Aims: A plethora of mutations in the LDL-receptor gene (LDLR) underlie the clinical phenotype of familial hypercholesterolaemia (FH). For the diagnosis of FH, it is important, however, to discriminate between pathogenic and non-pathogenic mutations. The aim of the current study was to assess whether true pathogenic mutations were indeed associated with the occurrence of coronary artery disease (CAD) when compared with non-functional variants. The latter variants should not exhibit such an association with CAD., Methods and Results: We assessed 29 365 individuals tested the 64 most prevalent LDLR variants. First, we determined pathogenicity for each of these sequence variants. Subsequently, a Cox-proportional hazard model was used to compare event-free survival, defined as the period from birth until the first CAD event, between carriers and non-carriers of LDLR mutations. Fifty-four sequence variants in the LDLR gene were labelled as pathogenic and 10 as non-pathogenic. The 9 912 carriers of a pathogenic LDLR mutation had a shorter event-free survival than the 18 393 relatives who did not carry that mutation; hazard ratio 3.64 [95% confidence interval (CI): 3.24-4.08; P< 0.001]. In contrast, the 355 carriers of a non-pathogenic LDLR variant had similar event-free survival as the 705 non-carrying relatives; hazard ratio 1.00 (95% CI: 0.52-1.94; P= 0.999)., Conclusion: These findings with respect to clinical outcomes substantiate our criteria for functionality of LDLR sequence variants. They also confirm the CAD risk associated with FH and underline that these criteria can be used to decide whether a specific sequence variant should be used in cascade screening.

Aims Autosomal dominant hypercholesterolaemia (ADH) is a major risk factor for coronary artery disease. This disorder is caused by mutations in the genes coding for the low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), and proprotein convertase subtilisin/kexin 9 (PCSK9). However, in 41% of the cases, we cannot find mutations in these genes. In this study, new genetic approaches were used for the identification and validation of new variants that cause ADH. Methods and results Using exome sequencing, we unexpectedly identified a novel APOB mutation, p.R3059C, in a small-sized ADH family. Since this mutation was located outside the regularly screened APOB region, we extended our routine sequencing strategy and identified another novel APOB mutation (p.K3394N) in a second family. In vitro analyses show that both mutations attenuate binding to the LDLR significantly. Despite this, both mutations were not always associated with ADH in both families, which prompted us to validate causality through using a novel genetic approach. Conclusion This study shows that advances in genetics help increasing our understanding of the causes of ADH. We identified two novel functional APOB mutations located outside the routinely analysed APOB region, suggesting that screening for mutations causing ADH should encompass the entire APOB coding sequence involved in LDL binding to help identifying and treating patients at increased cardiovascular risk.

Aims: Statins are essential for the reduction of risk of coronary heart disease (CHD) in familial hypercholesterolemia (FH). One of many genes influenced by statin treatment is the ATP-binding cassette transporter A1 (ABCA1) gene, which plays an important role in metabolism of high-density lipoprotein (HDL). The present aim was to test if the ABCA1 C69T polymorphism influences CHD risk and response to statin treatment., Methods and Results: In a large cohort of 1686 FH patients without a history of CHD before 1 January 1990, we analysed statin-ABCA1 C69T polymorphism interaction by comparing treated and untreated patients. We used a Cox proportional hazard model adjusted for sex, birth year, and smoking. In analyses restricted to untreated patients, the TT genotype was associated with 1.7 times higher CHD risk than the CC genotype (hazard ratio (HR) =1.65, 95% confidence interval (95% CI): 1.08-2.53; P = 0.02). Conversely, in statin-treated FH patients, CHD risk in TT individuals was not increased (HR: 0.65, 95% CI: 0.35-1.24; P = 0.2). Formal testing confirmed this interaction (P = 0.03). HDL-cholesterol levels were significantly more raised in statin-treated patients with the TT than with the CC genotype (two-way ANOVA, P = 0.045)., Conclusion: In untreated FH patients, the TT genotype of the ABCA1 C69T polymorphism was associated with increased CHD risk. However, in statin-treated patients, CHD risk was no longer significantly different between genotypes, at least partially explained by a higher rise in HDL-cholesterol levels during statin treatment in TT individuals.

Aims: The presence of tendon xanthomas is a marker of high risk of cardiovascular disease (CVD) among patients with familial hypercholesterolaemia (FH). Therefore, xanthomas and atherosclerosis may result from the same pathophysiological mechanisms. Reverse cholesterol transport (RCT) and low-density lipoprotein (LDL) oxidation are pathophysiological pathways of atherosclerosis, and it is well established that genetic variation in these pathways influences CVD risk. We therefore determined whether genetic variation in these pathways is also associated with the occurrence of tendon xanthomas in FH patients., Methods and Results: Four genetic variants in each pathway were genotyped in 1208 FH patients. We constructed a gene-load score for both pathways. The odds of xanthomas increased with the number of the risk alleles in the RCT pathway (OR 1.21, 95% CI 1.08-1.36, P(trend) = 0.0014). Similarly, higher numbers of risk alleles in the LDL oxidation pathway were associated with the presence of xanthomas (OR 1.24, 95% CI 1.08-1.41, P(trend) = 0.0015)., Conclusion: The presence of tendon xanthomas in FH patients is associated with genetic variation in the RCT and LDL oxidation pathways. These results support the hypothesis that xanthomas and atherosclerosis share pathophysiological mechanisms.

Aims: Activation of the complement system seems an important link between inflammation and atherogenesis. The Y402H polymorphism of complement factor H (CFH) has been associated with cardiovascular events, but results are conflicting and possibly modified by age of onset of cardiovascular disease (CVD)., Methods and Results: We determined whether or not the Y402H polymorphism influenced CVD risk in a multicentre cohort study involving 2,016 unrelated patients with familial hypercholesterolaemia (FH), who have an extremely increased susceptibility to premature CVD. We identified 261 individuals who were homozygous for the polymorphism (CC genotype; 12.9%), 929 individuals who were heterozygous (TC genotype; 46.1%), and 826 individuals carried the wild-type (TT genotype; 41.0%). During 95 115 person years, 644 patients had a cardiovascular event. Carriers of the CC genotype had a decreased risk of CVD (hazard ratio 0.67, 95% confidence interval 0.51-0.87; P = 0.003) relative to the other genotype groups. This association was unaltered after adjustment for clinically relevant cardiovascular risk factors or age effects., Conclusion: Among patients with severely increased risk of early onset CVD, the Y402H CFH variant was inversely associated with susceptibility to CVD. This suggests that CFH is a modifier gene of CVD.

Context: Glucocorticoids contribute to the development of atherosclerosis. Four polymorphisms in the glucocorticoid receptor (GR) gene have been reported to alter glucocorticoid sensitivity and have been associated with cardiovascular risk factors. Studies on the relationship between these GR variants and cardiovascular disease (CVD) risk, however, have yielded conflicting results., Objective: We sought to determine whether haplotypes based on functional polymorphisms in the GR gene influenced susceptibility to CVD in a high-risk population., Design, Setting, and Participants: In a multicenter cohort study, 1830 patients with heterozygous familial hypercholesterolemia were genotyped for the functional ER22/23EK, N363S, BclI, and 9beta variants. We analyzed the combined effect of all GR variants by constructing haplotypes and using a Cox proportional hazards regression model with adjustment for year of birth and smoking. The analyses were stratified for sex., Main Outcome Measures: The primary outcome measure was CVD defined as coronary, cerebral, and peripheral artery disease., Results: A total of 359 men (40.8%) and 224 women (23.6%) had a cardiovascular event. In men, the BclI haplotype was associated with a 34% higher CVD risk (confidence interval 1.02-1.76; P = 0.03) and the 9beta haplotype with a 41% higher CVD risk (confidence interval 1.02-1.94; P = 0.04). In women, none of the GR haplotypes was significantly related with CVD. We did not find differences in cardiovascular risk factors between GR haplotypes., Conclusions: In this large cohort of high-risk individuals, two common haplotypes in the GR gene modified CVD susceptibility among men.

Aims: Recent large association studies have revealed associations between genetic polymorphisms and myocardial infarction and coronary heart disease (CHD). We performed a replication study of 10 polymorphisms and CHD in a population with familial hypercholesterolemia (FH), individuals at extreme risk of CHD., Methods and Results: We genotyped 10 polymorphisms in 2145 FH patients and studied the association between these polymorphisms and CHD in Cox proportional hazards models. We confirmed the associations between four polymorphisms and CHD, the rs1151640 polymorphism in the olfactory receptor family 13 subfamily G member 1 (OR13G1) gene (HR 1.14, 95% CI 1.01-1.28, P = 0.03), the rs11881940 polymorphism in the heterogeneous nuclear ribonucleoprotein U-like 1 (HNRPUL1) gene (HR 1.27, 95% CI 1.07-1.51, P = 0.007), the rs3746731 polymorphism in the complement component 1 q subcomponent receptor 1 (CD93) gene (HR 1.26, 95% CI 1.06-1.49, P = 0.01), and the rs10757274 polymorphism near the cyclin-dependent kinase N2A and N2B (CDKN2A and CDKN2B) genes (HR 1.39, 95% CI 1.15-1.69, P < 0.001)., Conclusion: We confirmed previously found associations between four polymorphisms and CHD, but refuted associations for six other polymorphisms in our large FH population. These findings stress the importance of replication before genetic information can be implemented in the prediction of CHD.

Aims: Familial hypercholesterolaemia (FH) is characterized by premature coronary heart disease (CHD). However, the incidence of CHD varies considerably among FH patients. Genetic variation in the renin-angiotensin-aldosterone system (RAAS) and the adrenalin/noradrenalin system may be of importance in determining the CHD risk in FH, because of their involvement in CHD. We investigated the association between CHD risk and combined genetic variation in the RAAS and adrenalin/noradrenalin system., Methods and Results: In 2190 FH patients, we genotyped six RAAS polymorphisms and five adrenalin/noradrenalin polymorphisms. For each patient, we calculated two gene-load scores by counting the number of risk genotypes within each pathway. Four of the six RAAS polymorphisms and none of the polymorphisms in the adrenalin/noradrenalin system were significantly associated with CHD (P < 0.05). The RAAS gene-load score was significantly associated with CHD (P(linear trend) < 0.001): in patients with a gene-load score of 5 or 6, the CHD risk was 2.3 times as high as in patients with a score of 0 or 1. The gene-load score of the adrenalin/noradrenalin system was not associated with CHD., Conclusion: Genetic variation in the RAAS contributes gene-dose dependently to CHD risk in patients with FH, whereas genetic variation in the adrenalin/noradrenalin system is not associated with CHD.

Aims: To investigate the influence of different LDL-receptor (LDLR) gene mutations on age at first cardiovascular event in familial hypercholesterolaemia (FH) patients., Methods and Results: Dutch FH patients (n = 862) with known LDLR mutations from a retrospective cohort study were included. A gamma frailty Cox model was used. An event was defined as the first cardiovascular event. Gender, hypertension, smoking, diabetes, HDL cholesterol, LDL cholesterol (LDL-C), or triglycerides were included as covariates. Furthermore, the effect of LDLR mutation type on LDL and HDL cholesterol levels was investigated using mixed effects models, including gender, smoking, body mass index, and age at time of lipid measurement as covariates. A total of 86 different LDLR mutations were present in this cohort. Twenty-two percent of patients experienced an event (median age: 47.1 year; range: 25.6-85.8 years). The effect of LDLR mutation type on event-free survival is only significant in the models without LDL-C levels. Also, LDLR mutation type was significantly associated with LDL-C levels (P = 0.007), but not with HDL cholesterol levels (P = 0.12)., Conclusion: In the present study, LDL-C levels are a more important risk factor of event-free survival than the type of LDLR mutation.

Context: Individuals with the functional ER22/23EK variant in the glucocorticoid receptor gene are relatively resistant to the downstream consequences of glucocorticoids. Evidence suggests that carriers have a more favorable cardiovascular risk profile, but the relationship between this ER22/23EK variant and cardiovascular disease has not been hitherto assessed., Objective: We, therefore, determined whether carriership of the ER22/23EK improves cardiovascular disease risk in patients with severe hypercholesterolemia., Design, Setting, and Participants: In a multicenter cohort study, 2024 patients with heterozygous familial hypercholesterolemia, aged 18 yr and older, were genotyped for the ER22/23EK polymorphism. Patients were identified at lipid clinics throughout The Netherlands between 1989 and 2002., Main Outcome Measures: The primary outcome measure was cardiovascular disease., Results: Seventy-six (7.8%) of 977 men and 72 (6.9%) of 1047 women were carriers of the ER22/23EK variant. A total of 395 men and 247 women had a cardiovascular event. In contrast to expected results, we observed no significant association of the ER22/23EK variant with cardiovascular disease risk (men: relative risk, 0.75; 95% confidence interval, 0.50-1.14; P = 0.2; women: relative risk, 1.37; 95% confidence interval, 0.82-2.28; P = 0.2). However, we found a significant interaction between gender and the polymorphism on cardiovascular disease (P = 0.02)., Conclusions: In this large cohort of individuals with very high risk of cardiovascular disease, the association between the functional ER22/23EK polymorphism and cardiovascular risk was not significant overall, although it varied significantly by gender.

Aims: We assembled a cohort of patients with familial hypercholesterolaemia (FH) for both basic and clinical research. We used a set of established diagnostic criteria to define FH. Some put forward that a definite diagnosis of FH is made when a mutation in the LDL-receptor (LDLR) gene is identified. We therefore set out to determine in these patients whether patients with a DNA diagnosis would differ significantly from those diagnosed clinically., Methods and Results: We randomly selected 4000 hypercholesterolaemic patients from the Dutch Lipid Clinic network database. Phenotypical data were acquired by reviewing medical records. After review of medical records, 2400 patients could be defined as having FH. An LDLR mutation was identified in 52.3% of these patients. Patients with and without an LDLR mutation demonstrated different clinical and laboratory characteristics. Low-density lipoprotein cholesterol was higher in patients with an LDLR mutation, whereas triglycerides were higher in patients without an LDLR mutation. The phenotypic differences between the groups remained even after stratification for the presence or absence of tendon xanthomas., Conclusion: Despite the use of stringent clinical criteria to define FH patients, two cohorts could be identified within our study population, namely those patients with and those without an LDLR mutation. Our findings suggest that among those without an LDLR mutation, patients with other causes of dyslipidaemia may be present. These observations underline the relevance of genetic testing in FH for clinical practice, for screening purposes, and for research involving these patients.