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BackgroundHeart disease is the leading cause of premature death for women in Canada. Ischemic heart disease (IHD) is categorized as myocardial infarction (MI) with no obstructive coronary artery disease (MINOCA), ischemia with no obstructive coronary arteries (INOCA), and atherosclerotic obstructive coronary artery disease (CAD) with MI (MI-CAD) or without MI (non-MI CAD). This study aims to study the prevalence of traditional and non-traditional IHD risk factors and their relationships with (M)INOCA compared to MI-CAD and non-MI CAD in young women.MethodsThis study investigated women who presented with premature (≤55 years old) vasomotor entities of (M)INOCA or obstructive CAD confirmed by coronary angiography, who are currently enrolled in either the Leslie Diamond Women’s Heart Health Clinic Registry (WHC) or the Study to Avoid cardioVascular Events in BC (SAVEBC). Univariable and multivariable regression models were applied to investigate associations of risk factors with odds of (M)INOCA, MI-CAD or non-MI CAD.ResultsA total of 254 women enrolled between 2015-2022 were analyzed: 77 INOCA and 37 MINOCA from the WHC and 66 with non-MI CAD and 74 MI-CAD from SAVEBC. Regression analyses demonstrated that migraines and preeclampsia/gestational hypertension were the most significant risk factors with higher likelihood to associate with premature (M)INOCA relative to obstructive CAD. Conversely, the presence of diabetes and a current or previous smoking history had the highest likelihood to associate with premature CAD.ConclusionThere are significant differences in the risk factor profiles of patients with premature (M)INOCA compared to obstructive CAD.

Familial hypercholesterolemia (FH), familial combined hyperlipidemia (FCHL), and elevated lipoprotein (a) (Lp[a]) increase risk of premature coronary artery disease (CAD). The objective of this study was to assess the prevalence of FH, FCHL, elevated Lp(a) and their impact on management in patients with premature CAD.We prospectively recruited men ≤ 50 years and women ≤ 55 with obstructive CAD. FH was defined as Dutch Lipid Clinic Network scores ≥ 6. FCHL was defined as apolipoprotein B1.2 g/L, triglyceride and total cholesterol90th population percentile, and family history of premature cardiovascular disease. Lp(a) ≥ 50 mg/dL was considered to be elevated.Among 263 participants, 9.1% met criteria for FH, 12.5% for FCHL, and 19.4% had elevated Lp(a). Among patients with FH, 37.5% had FH-causing DNA variants. Patients with FH, but not other dyslipidemias, were more likely than nondyslipidemic patients to have received lipid-lowering therapy before presenting with CAD (33.3% vs 12.3%, P = 0.04) and combined lipid-lowering therapy after the presentation (41.7% vs 7.7%, P0.001). One year after presentation, 58.3%, 54.5%, and 58.8% of patients with FH, FCHL, and elevated Lp(a) had low-density lipoprotein cholesterol (LDL-C)1.8 mmol/L, respectively, compared with 68.0 % in reference group. Patients with FCHL were more likely to have non-high-density lipoprotein (HDL) and apolipoprotein B above recommended lipid goals (70.0% and 87.9%, respectively).FH, FCHL, and elevated Lp(a) are common in patients with premature CAD and have differing impact on treatment and achievement of lipid targets. Assessment for these conditions in patients with premature CAD provides valuable information for individualized management.

Literature review of patients with KCNQ2 developmental and epileptic encephalopathy (KCNQ2‐DEE) reveals, based on 16 reports including 139 patients, a clinical phenotype that includes age‐ and disease‐specific stereotyped seizures. The typical seizure type of KCNQ2‐DEE, focal tonic, starts within 0‐5 days of life and is readily captured by video‐electroencephalography VEEG for clinical and genetic diagnosis. After initial identification, KCNQ2‐DEE seizures are clinically apparent and can be clearly identified without the use of EEG or VEEG. Therefore, we propose that the 2019 recommendations from the International League against Epilepsy (ILAE), the Pediatric Epilepsy Research Consortium (PERC), for capturing and recording seizures for clinical trials (Epilepsia Open, 4, 2019, 537) are suitable for use in KCNQ2‐DEE‒associated antiseizure medicine (ASM) treatment trials. The ILAE/PERC consensus guidance states that a caregiver‐maintained seizure diary, completed by caregivers who are trained to recognize seizures using within‐patient historical recordings, accurately captures seizures prospectively in a clinical trial. An alternative approach historically endorsed by the Food and Drug Administration (FDA) compares seizure counts captured on VEEG before and after treatment. A major advantage of the ILAE/PERC strategy is that it expands the numbers of eligible patients who meet inclusion criteria of clinical trials while maintaining accurate seizure counts (Epilepsia Open, 4, 2019, 537). Three recent phase 3 pivotal pediatric trials investigating ASMs to treat syndromic seizures in patients as young as 2 years of age (N Engl J Med, 17, 2017, 699; Lancet, 21, 2020, 2243; Lancet, 17, 2018, 1085); and ongoing phase 2 open‐label pediatric clinical trial that includes pediatric epileptic syndromes as young as 1 month of age (Am J Med Genet A, 176, 2018, 773), have already used caregiver‐maintained seizure diaries successfully. For determining the outcome of a KCNQ2‐DEE ASM treatment trial, the use of a seizure diary to count seizures by trained observers is feasible because the seizures of KCNQ2‐DEE are clinically apparent. This strategy is supported by successful precedent in clinical trials in similar age groups and has the endorsement of the international pediatric epilepsy community.

NBI-921352 (formerly XEN901) is a novel sodium channel inhibitor designed to specifically target NaV1.6 channels. Such a molecule provides a precision-medicine approach to target SCN8A-related epilepsy syndromes (SCN8A-RES), where gain-of-function (GoF) mutations lead to excess NaV1.6 sodium current, or other indications where NaV1.6 mediated hyper-excitability contributes to disease (Gardella and Møller, 2019; Johannesen et al., 2019; Veeramah et al., 2012). NBI-921352 is a potent inhibitor of NaV1.6 (IC500.051 µM), with exquisite selectivity over other sodium channel isoforms (selectivity ratios of 756 X for NaV1.1, 134 X for NaV1.2, 276 X for NaV1.7, and >583 Xfor NaV1.3, NaV1.4, and NaV1.5). NBI-921352is a state-dependent inhibitor, preferentially inhibiting inactivatedchannels. The state dependence leads to potent stabilization of inactivation, inhibiting NaV1.6 currents, including resurgent and persistent NaV1.6 currents, while sparing the closed/rested channels. The isoform-selective profile of NBI-921352 led to a robust inhibition of action-potential firing in glutamatergic excitatory pyramidal neurons, while sparing fast-spiking inhibitory interneurons, where NaV1.1 predominates. Oral administration of NBI-921352 prevented electrically induced seizures in a Scn8a GoF mouse,as well as in wild-type mouse and ratseizure models. NBI-921352 was effective in preventing seizures at lower brain and plasma concentrations than commonly prescribed sodium channel inhibitor anti-seizure medicines (ASMs) carbamazepine, phenytoin, and lacosamide. NBI-921352 waswell tolerated at higher multiples of the effective plasma and brain concentrations than those ASMs. NBI-921352 is entering phase II proof-of-concept trials for the treatment of SCN8A-developmental epileptic encephalopathy (SCN8A-DEE) and adult focal-onset seizures.

Background Premature atherosclerotic cardiovascular disease (ASCVD) is highly heritable. The screening of first-degree relatives (FDR) of patients with premature ASCVD is recommended but not routinely performed, and the diagnostic yield of different approaches to such screening is unknown. Purpose To determine the feasibility and diagnostic yield of clinical and radiological screening of FDRs of patients with premature coronary artery disease (CAD) in clinical setting. Method We recruited FDRs of patients with angiographically-proven CAD with stenosis of ≥50% who presented at the age of ≤50 years for males and ≤55 years for females. After clinical and laboratory assessment, patients with no personal history of cardiovascular disease underwent either coronary computed tomography angiography (CCTA), coronary calcium scoring assessment (CAC), or carotid ultrasound (CUS). Subclinical atherosclerosis was defined as 1) CAC score >100 Agatston units or >75% percentile for age and sex; 2) Stenosis >50% in at least one coronary artery or segment involvement scores >50th percentile in males and >75th in females; or, 3) Carotid plaque on ultrasonography. Results We enrolled 220 FDRs between 2017 and 2020, 129 completed clinical assessment (Figure 1). Of them, 28 (21.7%) had a personal history of ASCVD and 101 were tested for subclinical atherosclerosis. The characteristics of these patients are shown in Table 1. The most prevalent cardiovascular risk factors were dyslipidemia (40.6%), hypertension (22.8%), and obesity (21.8%). When assessed with the Framingham risk score calculator without adjustment for family history, only 5.1% and 28.6%, of patients had high or moderate cardiovascular risk, respectively. After adjusting for family history and the presence of statin-indicated conditions, 39.6% and 14.9% of patients were placed in high and moderate risk groups, respectively. Subclinical atherosclerosis was found in 43.6% of all patients (Figure 1) and 57.7% of patients over 40 years of age. The diagnostic yield of procedures was 29.6% for CUS, 37.8% for CCTA and 61.1% for CAC scoring. After the radiological assessment, 13.9% of patients were reclassified to a higher risk group (Table 1). Conclusion Non-invasive cardiovascular imaging detected subclinical atherosclerosis in 43.6% of healthy patients with a family history of premature ASCVD, moving 1 in 7 patients to a higher risk group and suggesting that this screening approach may improve risk prediction in this population. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Canadian Institutes of Health Research.St. Paul's Hospital Foundation and the Vancouver General Hospital Foundation. Figure 1Table 1

NBI-921352 (formerly XEN901) is a novel sodium channel inhibitor designed to specifically target NaV1.6 channels. Such a molecule provides a precision-medicine approach to target SCN8A-related epilepsy syndromes (SCN8A-RES), where gain-of-function (GoF) mutations lead to excess NaV1.6 sodium current, or other indications where NaV1.6 mediated hyper-excitability contributes to disease (Gardella and Moller, 2019; Johannesen et al., 2019; Veeramah et al., 2012). NBI-921352 is a potent inhibitor of NaV1.6 (IC50 0.051 µM), with exquisite selectivity over other sodium channel isoforms (selectivity ratios of 756X for NaV1.1, 134X for NaV1.2, 276X for NaV1.7, and >583X for NaV1.3, NaV1.4, and NaV1.5). NBI-921352 is a state-dependent inhibitor, preferentially inhibiting activated (inactivated or open) channels. The state dependence leads to potent stabilization of inactivation, inhibiting NaV1.6 currents, including resurgent and persistent NaV1.6 currents, while sparing the closed/rested channels. The isoform-selective profile of NBI-921352 led to a robust inhibition of action-potential firing in glutamatergic excitatory pyramidal neurons, while sparing fast-spiking inhibitory interneurons, where NaV1.1 predominates. Oral administration of NBI-921352 prevented electrically induced seizures in a Scn8a GoF mouse, as well as in wild-type mouse and rat seizure models. NBI-921352 was effective in preventing seizures at lower brain and plasma concentrations than commonly prescribed sodium channel inhibitor antiseizure medicines (ASMs) carbamazepine, phenytoin, and lacosamide. NBI-921352 was well tolerated at higher multiples of the effective plasma and brain concentrations than those ASMs. NBI-921352 is entering phase II proof-of-concept trials for the treatment of SCN8A-developmental epileptic encephalopathy (SCN8A-DEE) and adult focal-onset seizures.

NBI-921352 (formerly XEN901) is a novel sodium channel inhibitor designed to specifically target Na

BACKGROUND The screening of first-degree relatives (FDR) of patients with premature atherosclerotic cardiovascular disease (ASCVD) is recommended due to its high heritability. However, in practice such screening is not routinely performed, and the diagnostic yield of different approaches to screening and its impact on patient management is unknown. METHODS AND RESULTS We recruited FDRs of patients who presented with angiographically-confirmed ASCVD with stenosis of ≥ 50% of an epicardial coronary artery at the age of ≤ 50 years for males and ≤ 55 years for females. FDRs with no personal history of ASCVD underwent clinical assessment of cardiovascular risk and presence of inherited dyslipidemias, including familial hypercholesterolemia (FH), familial combined hyperlipidemia (FCHL), and elevated lipoprotein(a); and radiological testing for subclinical atherosclerosis (Figure 1). We enrolled 220 FDRs between 2017 and 2020, of which 129 completed clinical assessment (Figure 1). Of these, 28 had a personal history of ASCVD and 101 completed the full assessment. Patient characteristics are shown in Table 1. Based on the evaluation with modified FRS calculator and presence of statin-indicated conditions, 39.6% and 14.9% of patients were placed in high and moderate risk groups, respectively. In total, 24.1% of FDRs had an inherited dyslipidemias: 8.9% met clinical criteria for FH, 5.9% for FCHL, and 8.9% had lipoprotein(a) ≥ 500 mg/L. Of these, 22.2%, 40.0%, and 66.7%, respectively, had relatives with premature ASCVD with the same type of dyslipidemia. Subclinical atherosclerosis was detected in 43.6% of FDRs, and in 57.7% of those over 40 years of age. The diagnostic yield of each imaging modality was 29.6% for carotid ultrasound, 37.8% for cardiac CT and 61.1% for calcium scoring. Imaging led to upwards risk reclassification of 13.9% (Table 1). Based on this screening, lipid-lowering therapy was initiated in 29.7% of FDRs, and treatment was intensified in an additional 13.8%, while 7.9% had no change to treatment and 43.6% received therapeutic lifestyle change counselling. CONCLUSION A combination of clinical screening and non-invasive imaging identified the presence of an inherited dyslipidemia in one-quarter of FDRs of patients with premature ASCVD, and detected subclinical atherosclerosis in more than 40%. These findings led to treatment changes in more than 40% of these FDRs. These findings suggest that this screening approach may improve risk management in this population.

Background Type 2 diabetes mellitus (T2D) is a major cardiovascular risk factor (CVRF), and comprehensive risk factor management reduces the incidence of cardiovascular events. Purpose To assess 1) prevalence of T2D among patients presenting with newly diagnosed very premature coronary artery disease (CAD) and its impact on CVRFs and extent of atherosclerosis; 2) effectiveness of glucose and lipid control in T2D patients before presentation with CAD. Methods We studied patients with angiographically proven CAD with stenosis of ≥50% who presented at the age of ≤50 years for males and ≤55 years for females. Diabetes was defined as fasting plasma glucose ≥7 mmol/L, haemoglobin (Hb)A1C ≥6.5% or diagnosis or treatment of T2D before or at presentation with CAD. CVRFs were defined as dyslipidemia, hypertension, obesity, current smoking, and family history of premature cardiovascular disease (CVD). Values are reported as mean (±SD), median (interquartile range) or percentages. Results From 417 premature CAD patients, 112 (26.9%) had T2D at the time of presentation with CAD. In 27 (24.1%) patients, T2D was newly diagnosed at presentation with CAD. Age of diagnosis of T2D was 41.3 (±6.9) years old. Patients with T2D had higher prevalence of dyslipidemia (83.0% vs 63.3%, p Prior to presentation with CAD, 31 (27.7%) of T2D patients received insulin, 42 (37.5%) received oral hypoglycemic drugs, and 12 (10.7%) received no pharmacological treatment for diabetes. Only 23 (27.1%) of them achieved HbA1C ≤7% at the time of presentation with CAD (Figure 1). Among all T2D patients, 35 (31.3%) received treatment with statins and 16 (14.3%) reached guideline-recommended lipid targets of LDL cholesterol ≤2 mmol/L and/or non-HDL cholesterol ≤2.6 mmol/L. Conclusion Among patients with very premature CAD, T2D was common, was previously unrecognized in up to one quarter, and was associated with a greater burden of CVRFs and more extensive CAD at presentation. Few patients with T2D achieved guideline-recommended lipid or glucose targets. These data point to the need for improvements in screening and comprehensive CVRF treatment of T2D in order to reduce the burden of premature CAD. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Canadian Institutes of Health Research. St. Paul's Hospital Foundation and the Vancouver General Hospital Foundation

Objective The objective was to evaluate the safety and efficacy of TV-45070 ointment, as a treatment for postherpetic neuralgia, and to explore the response in patients with the Nav1.7 R1150W gain-of-function polymorphism. Materials and methods This was a randomized, placebo-controlled, 2-period, 2-treatment crossover trial. Patients with postherpetic neuralgia with moderate or greater pain received TV-45070 and placebo ointments, each applied twice daily for 3 weeks. The primary efficacy measure was the difference in change in mean daily pain score from baseline compared with the last week of placebo and active treatment. Secondary endpoints included responder rate analyses and a further exploratory analysis of response in carriers of the Nav1.7 R1150W polymorphism was conducted. Results Seventy patients were enrolled and 54 completed the study. TV-45070 was safe and well tolerated. No statistical difference was observed between treatments for the primary endpoint. However, the proportion of patients with ≥50% reduction in mean pain scores at week 3 was greater on TV-45070 than on placebo (26.8% vs. 10.7%, P=0.0039). Similarly, a greater proportion of patients on TV-45070 had a ≥30% reduction in mean pain scores at week 3 (39.3% on TV-45070 vs. 23.2% on placebo, P=0.0784). Of note, 63% of patients with the R1150W polymorphism versus 35% of wild-type carriers had a ≥30% reduction in mean pain score on TV-45070 at week 3 (no inferential analysis performed). Conclusions The 50% responder analysis suggests a subpopulation may exist with a more marked analgesic response to TV-45070.The trend toward a larger proportion of responders within Nav1.7 R1150W carriers warrants further investigation.

OBJECTIVE:Transcranial magnetic stimulation (TMS) produces characteristic deflections in the EEG signal named TMS-evoked EEG potentials (TEPs), which can be used to assess drug effects on cortical excitability. TMS can also be used to determine the resting motor threshold (RMT) for eliciting a minimal muscle response, as a biomarker of corticospinal excitability. XEN1101 is a novel potassium channel opener undergoing clinical development for treatment of epilepsy. We used TEPs and RMT to measure the effects of XEN1101 in the human brain, to provide evidence that XEN1101 alters cortical excitability at doses that might be used in future clinical trials.METHODS:TMS measurements were incorporated in this Phase I clinical trial to evaluate the extent to which XEN1101 modulates TMS parameters of cortical and corticospinal excitability. TEPs and RMT were collected before and at 2-, 4-, and 6-hours post drug intake in a double-blind, placebo-controlled, randomized, two-period crossover study of 20 healthy male volunteers.RESULTS:Consistent with previous TMS investigations of antiepileptic drugs (AEDs) targeting ion channels, the amplitude of TEPs occurring at early (15-55 msec after TMS) and at late (150-250 msec after TMS) latencies were significantly suppressed from baseline by 20 mg of XEN1101. Furthermore, the RMT showed a significant time-dependent increase that correlated with the XEN1101 plasma concentration.INTERPRETATION:Changes from baseline in TMS measures provided evidence that 20 mg of XEN1101 suppressed cortical and corticospinal excitability, consistent with the effects of other AEDs. These results support the implementation of TMS as a tool to inform early-stage clinical trials.

Introduction Family history of premature coronary artery disease (CAD) is known to predispose individuals to adverse CAD events, often at a younger age. Current risk stratification strategy is suboptimal, as up to 50% of individuals were considered “low-risk” prior to their first presentation of myocardial infarction. Coronary artery calcium score (CACS) is a marker of atherosclerosis and provides incremental value in risk stratification. However, the utility of CACS may be limited in younger patients as they often have non-calcified atherosclerotic plaques. In this study, we evaluate the sensitivity of CACS in detecting subclinical atherosclerosis in different age groups. Method From 310 referrals to a specialized unit in the management of early atherosclerosis, 222 individuals with a family history of premature CAD (defined as CAD events in first-degree family members, male Results Of the 141 (59% male, mean age 45.9±6.0 year) individuals that completed clinical evaluation, 65 (73% male, mean age 47.4±6.9 years) have subclinical atherosclerosis (defined by the presence of atherosclerotic plaques in any of the coronary artery segments in cardiac CT). Of them, 52 have CACS>0, giving an overall sensitivity of 80%. The breakdown by age group is shown in table 1. The sensitivity of CACS in detecting subclinical atherosclerosis is quite modest in younger individuals (60% in individuals 85% in >45 years). Table 1. Sensitivity of CACS in different age groups Age group True Positive Fast Negative Sensitivity N (CAC+ CTCA+) (CAC+ CTCA−) (%) Conclusion In younger individuals (

Introduction Patients with family history of premature coronary artery disease (CAD) are at increased risk of CAD events at a younger age. Risk factor based approaches and clinical evaluation are most commonly used to assess these individuals. However, it has been recently shown that up to 50% of individual presenting with their first myocardial infarction (MI) were considered to be “low risk” prior to that event. MI is often a result of plaque rupture preceded by progression of subclinical atherosclerosis. Detection of subclinical atherosclerosis may therefore help target prevention of plaque progression. We assessed the value of clinical risk factor, biomarkers and Framingham Risk Score (FRS) in predicting subclinical atherosclerosis in individuals with a family history of premature CAD. Methods From 310 referrals, 222 individuals between the ages of 35 and 55 with a family history of premature CAD (CAD events in first-degree family members (male Results In this pilot, 141 individuals (59% male, mean age 45.9±6.0 years) completed evaluation, and 65 (46%) had evidence of subclinical atherosclerosis on CT coronary angiography or CT calcium score with a mean segment involvement score (SIS) of 2.8 and mean CS of 152, putting them above the 80th percentile for their age and sex. Aside from male sex, age, and smoking history, other traditional risk factors and biomarkers including diabetes mellitus, hypertension, total cholesterol, LDL-C, HDL-C and Cholesterol/HDL-C were not significantly different between those with or without subclinical atherosclerosis (Table 1). Table 1 Conclusion In young individuals with a family history of premature CAD, risk factors, biomarkers, and FRS failed to identify individuals with premature, subclinical atherosclerosis in this pilot study. Detection of subclinical atherosclerosis and early implementation of treatment with the aim of stabilizing plaques and stopping progression might prove vital in reducing events in these individuals. Further studies are warranted.

Background The incidence of atherosclerotic cardiovascular disease has declined in the past 2 decades. However, these benefits may not extend to young patients. The objective of this work was to assess temporal trends in the incidence, risk profiles, sex‐related differences, and outcomes in a contemporary population of young patients presenting with coronary artery disease ( CAD ) in British Columbia, Canada. Methods and Results We used a provincial cardiac registry to identify young patients (men aged CAD between 2000 and 2016, who had either ≥50% stenosis of ≥1 coronary arteries on angiography or underwent coronary revascularization. A total of 12 519 patients (30% women) met our inclusion criteria. The incidence of CAD remained stable and was higher for men than women (46–53 versus 18–23 per 100 000). Of patients, 92% had at least one traditional cardiovascular risk factor and 67% had multiple risk factors. The prevalence of diabetes mellitus, obesity, and hypertension increased during the study period and was higher for women. Women had fewer emergent procedures and revascularizations. Mortality rates decreased by 31% between 2000 and 2007, then were stable for the remaining 9 years. Mortality was significantly higher for women aged Conclusions The incidence of premature CAD has not declined, and the prevalence of 3 major cardiovascular risk factors increased between 2000 and 2016. The risk burden and mortality rates were worse for women. These data have important implications for the design of strategies to prevent CAD in young adults.

Objectives: Despite advances in screening and prevention, rates of premature coronary artery disease (CAD) have been stagnant. The goals of this study were to investigate the barriers to early risk detection and preventive treatment in patients with premature CAD. In particular, we: 1) assessed the performance of the latest versions of major international guidelines in detection of risk of premature CAD and eligibility for preventive treatment; and, 2) investigated real-life utilization of primary prevention with lipid-lowering therapies in these patients. Methods: We included patients in the Study to Avoid cardioVascular Events in British Columbia (SAVE BC), an observational study of patients with premature (males ​≤ ​50 years, females ​≤ ​55 years) angiographically confirmed CAD. Eligibility for primary prevention and treatment received were assessed retrospectively based on information recorded prior to or at the index presentation with CAD. Results: Of 417 patients (28.1% females) who met the criteria, 94.3% had at least one major cardiovascular risk factor. In the retrospective risk assessment, 41.7%, 61.4%, and 34.3% (p ​

Atherosclerotic cardiovascular disease (ASCVD) is highly heritable, particularly when it occurs at a young age. The screening of individuals with premature ASCVD, although often recommended, is not routinely performed. Strategies to address this gap in care are essential. We designed the Study to Avoid CardioVascular Events in British Columbia (SAVE BC) as a prospective, observational study of individuals with a new diagnosis of very premature ASCVD (defined as age ≤ 50 years in males and age ≤ 55 years in females) and their first-degree relatives (FDRs) and spouses. FDRs and spouses will undergo screening for cardiovascular (CV) risk factors and subclinical ASCVD using a structured screening algorithm. All subjects will be followed longitudinally for ≥10 years. The overall goal of SAVE BC is to evaluate the yield of a structured screening program for identifying individuals at risk of premature ASCVD. The primary objectives of SAVE BC are to identify and follow index cases with very premature ASCVD and their FDRs and to determine the diagnostic yield of a structured screening program for these individuals. We will collect data on CV risk factors, medication use, CV events, and healthcare costs in these individuals. SAVE BC will provide insight regarding approaches to identify individuals at risk for premature ASCVD with implications for prevention and treatment in this population.

Background— Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetically heterogeneous condition caused by mutations in genes encoding desmosomal proteins in up to 60% of cases. The 40% of genotype-negative cases point to the need of identifying novel genetic substrates by studying genotype-negative ARVC families. Methods and Results— Whole exome sequencing was performed on 2 cousins with ARVC. Validation of 13 heterozygous variants that survived internal quality and frequency filters was performed by Sanger sequencing. These variants were also genotyped in all family members to establish genotype–phenotype cosegregation. High-resolution melting analysis followed by Sanger sequencing was used to screen for mutations in cadherin 2 ( CDH2 ) gene in unrelated genotype-negative patients with ARVC. In a 3-generation family, we identified by whole exome sequencing a novel mutation in CDH2 (c.686A>C, p.Gln229Pro) that cosegregated with ARVC in affected family members. The CDH2 c.686A>C variant was not present in >200 000 chromosomes available through public databases, which changes a conserved amino acid of cadherin 2 protein and is supported as the causal mutation by parametric linkage analysis. We subsequently screened 73 genotype-negative ARVC probands tested previously for mutations in known ARVC genes and found an additional likely pathogenic variant in CDH2 (c.1219G>A, p.Asp407Asn). CDH2 encodes cadherin 2 (also known as N-cadherin), a protein that plays a vital role in cell adhesion, making it a biologically plausible candidate gene in ARVC pathogenesis. Conclusions— These data implicate CDH2 mutations as novel genetic causes of ARVC and contribute to a more complete identification of disease genes involved in cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetically heterogeneous condition caused by mutations in genes encoding desmosomal proteins in up to 60% of cases. The 40% of genotype-negative cases point to the need of identifying novel genetic substrates by studying genotype-negative ARVC families.Whole exome sequencing was performed on 2 cousins with ARVC. Validation of 13 heterozygous variants that survived internal quality and frequency filters was performed by Sanger sequencing. These variants were also genotyped in all family members to establish genotype-phenotype cosegregation. High-resolution melting analysis followed by Sanger sequencing was used to screen for mutations in cadherin 2 (These data implicate

Item does not contain fulltext Mutations in the SCN9A gene leading to deficiency of its protein product, Na(v)1.7, cause congenital indifference to pain (CIP). CIP is characterized by the absence of the ability to sense pain associated with noxious stimuli. In contrast, the opposite phenotype to CIP, inherited erythromelalgia (IEM), is a disorder of spontaneous pain caused by missense mutations resulting in gain-of-function in Na(v)1.7 that promote neuronal hyperexcitability. The primary aim of this study was to demonstrate that Na(v)1.7 antagonism could alleviate the pain of IEM, thereby demonstrating the utility of this opposite phenotype model as a tool for rapid proof-of-concept for novel analgesics. An exploratory, randomized, double-blind, 2-period crossover study was conducted in 4 SCN9A mutation-proven IEM patients. In each treatment period (2days), separated by a 2-day washout period, patients were orally administered XEN402 (400mg twice daily) or matching placebo. In 3 patients, pain was induced by heat or exercise during each treatment arm. A fourth patient, in constant severe pain, required no induction. Patient-reported outcomes of pain intensity and/or relief were recorded, and the time taken to induce pain was measured. The ability to induce pain in IEM patients was significantly attenuated by XEN402 compared with placebo. XEN402 increased the time to maximal pain induction and significantly reduced the amount of pain (42% less) after induction (P=.014). This pilot study showed that XEN402 blocks Na(v)1.7-mediated pain associated with IEM, thereby demonstrating target engagement in humans and underscoring the use of rare genetic disorders with mutant target channels as a novel approach to rapid proof-of-concept.

Objective The association between polymorphisms in candidate genes related to lipoprotein metabolism and the reduction in plasma triglyceride (TG) in response to fenofibrate treatment was evaluated in subjects with type 2 diabetes treated with micronized fenofibrate (200 mg/day) for at least 3 years in the Diabetes Atherosclerosis Intervention Study. Methods The cholesteryl ester transfer protein Taq1B, LPL S447X, hepatic lipase -514 C-->T, peroxisome-proliferator-activated receptors alpha (PPARA) L162V and G/C intron 7 polymorphisms and the apolipoprotein E2/E3/E4 alleles were genotyped using PCR and restriction enzyme digestion. Subjects were divided into high TG-responders (with >30% TG relative reduction after treatment) and low TG-responders. Results The frequency of the PPARA intron 7 G/G genotype was higher in high TG-responders than in low TG-responders (85% vs. 69%, P 30% after fenofibrate treatment in patients with type 2 diabetes. (C) 2004 Lippincott Williams Wilkins

The purpose of this study was to determine whether genetic linkage or association could be observed between schizophrenia (SZ) and the CAG repeat polymorphisms within the genes KCNN3 (known previously as hSKCa3) and PPP2R2B (linked to Spino-Cerebellar Atrophy 12) in the Xhosa population in South Africa. Neither locus has been studied previously in African populations. The polymorphisms were genotyped in 589 individuals to form samples for Transmission Disequilibrium Test (TDT) analysis (176 unrelated probands, 145 with both parents and 30 with one parent genotyped), linkage analysis (49 families with 54 independent affected sib pairs [ASPs]), and case-control analyses (67 familial cases with a first-degree SZ relative, 101 sporadic cases with no affected first- or second-degree relative, and 90 control cases). No significant differences were found among familial cases, sporadic cases and controls in allele sizes (Kruskal-Wallis tests) or the numbers of alleles with sizes above and below the mean size for each polymorphism. Allele size was not correlated with age of onset (Spearman correlation). No significant evidence for association was observed using TDT analyses for all triads and separately for the familial triads. No significant evidence for linkage was observed for either locus with affected sib pair analysis using the possible triangle method or with Non-Parametric Linkage (NPL) analysis of the multiplex families. In conclusion, no significant evidence for linkage or association with SZ was observed for either polymorphism in this population.

Familial exudative vitreoretinopathy (FEVR) is a hereditary ocular disorder characterized by a failure of peripheral retinal vascularization. Loci associated with FEVR map to 11q13-q23 (EVR1; OMIM 133780, ref. 1), Xp11.4 (EVR2; OMIM 305390, ref. 2) and 11p13-12 (EVR3; OMIM 605750, ref. 3). Here we have confirmed linkage to the 11q13-23 locus for autosomal dominant FEVR in one large multigenerational family and refined the disease locus to a genomic region spanning 1.55 Mb. Mutations in FZD4, encoding the putative Wnt receptor frizzled-4, segregated completely with affected individuals in the family and were detected in affected individuals from an additional unrelated family, but not in normal controls. FZD genes encode Wnt receptors, which are implicated in development and carcinogenesis. Injection of wildtype and mutated FZD4 into Xenopus laevis embryos revealed that wildtype, but not mutant, frizzled-4 activated calcium/calmodulin-dependent protein kinase II (CAMKII) and protein kinase C (PKC), components of the Wnt/Ca(2+) signaling pathway. In one of the mutants, altered subcellular trafficking led to defective signaling. These findings support a function for frizzled-4 in retinal angiogenesis and establish the first association between a Wnt receptor and human disease.

Abstract —The D9N substitution is a common mutation in the lipoprotein lipase (LPL) gene. This mutation has been associated with reduced levels of HDL cholesterol and elevated triglycerides (TG) in a wide variety of patients. We investigated the influence of this D9N mutation on lipid and lipoprotein levels and risk for cardiovascular disease (CVD) in patients with familial hypercholesterolemia (FH). A total of 2091 FH heterozygotes, all of Dutch extraction, were screened for the D9N mutation using standard polymerase chain reaction techniques, followed by specific enzyme digestion. A total of 94 FH subjects carrried the D9N mutation at a carrier frequency of 4.5%. Carriers of other common LPL mutations, such as the N291S and the S447X were excluded. Clinical data on 80 FH individuals carrying the D9N were available and were compared with a FH control group matched for age, sex, and body mass index (n=203). Analysis revealed significantly higher TG ( P =0.01) and lower HDL-cholesterol levels ( P =0.002). Dyslipidemia was more pronounced in D9N carriers with higher body mass index. Moreover, FH patients carrying this common LPL mutation were at higher risk for CVD, (odds ratio=2.8; 95% CI, 1.43 to 5.32; P =0.002). The common D9N LPL mutation leads to increased TG and decreased HDL plasma levels in patients with FH. These effects are most apparent in those FH heterozygotes with an increased body mass index. Furthermore, this mutation, present in 4.5% of Dutch FH heterozygotes, leads to increased risk for CVD.

We assessed the effect of two common mutations in the lipoprotein lipase gene (LPL), D9N and N291S, which have been shown to modulate plasma lipids in a wide spectrum of patients. A total of 1114 men and 1 144 women from the Framingham Offspring Study (FOS) were analyzed for these two LPL variants. Subsequently, the association with fasting plasma lipids and risk of coronary artery disease (CHD) was determined. We extended our study by calculating weighed means of lipids and lipoproteins in carriers and non-carriers for these LPL mutations in patients with genetic dyslipidemias, CHD patients and healthy controls. In the FOS sample, the D9N and N291S alleles were associated with lower high-density lipoprotein-cholesterol (HDL-C) (delta = - 0.07 mmol/ 1, p = 0.03) and a trend towards increased triglycerides (delta = 0.25 mmol/ 1, p = 0.07). In women, a trend towards the high triglyceride, low HDL-C phenotype was evident (delta = - 0.02 mmol/1 for HDL-C and delta = 0.14 mmol/l for triglycerides, respectively). Cumulative analysis of other studies of male carriers of the D9N and N291S revealed higher levels of triglycerides (D291N; 2.60(1.85) mmol/l vs. 1.62(1.18) mmol/l: p < 0.0001) (D9N; 1.94 (1.19) mmol/l vs. 1.74(1.17) mmol/l: p < 0.001) and lower HDL-C (N291S; 1.04(0.32) mmol/l vs. 1.15(0.28) mmol/l: p < 0.0001) (D9N; 1.08(0.24) mmol/l vs. 1.16(0.28) mmol/l: p < 0.0001). In females, results differed with higher TG levels (N291S; 1.70(0.99) mmol/l vs. 1.10(0.63) mmol/l: p < 0.001) (D9N; 1.08(0.76) mmol/l vs. 0.96(0.51) mmol/l: p < 0.01) and lower HDL-C levels (N291S; 1.27(0.33) mmol/l vs. 1.51(0.32) mmol/l: p < 0.0001); however, the HDL-C levels for D9N carriers were similar to non-carriers (D9N; 1.52(0.29) mmol/l vs. 1.53(0.35) mmol/l: p = 0.83). Our data provide evidence that common variants of the LPL gene are significant modulators of lipid and lipoprotein levels in both men and women.

Genetic variation at the lipoprotein lipase (LPL) locus has been shown to influence plasma lipids and to modulate risk of coronary heart disease (CHD). Recently, we found that the most frequent variant at this locus, involving a C-terminal truncation of two amino acids (Ser447X), was associated with both higher LPL activity and high density lipoprotein cholesterol (HDL-C) in patients with CHD. However, the impact of this S447X variant on lipids and CHD in the general population was hitherto unknown. We, therefore, analyzed a total of 1114 men and 1144 women randomly ascertained from the Framingham Offspring Study (FOS) for the presence of this LPL variant. Carrier frequency of the S447X allele was 17%, and in men carrier status was associated with higher total cholesterol (delta = 6.2 mg/dl, p = 0.03). higher HDL-C (delta = 2.3 mg/dl, p = 0.01), and lower triglyceride (TG) levels (delta = -19.4 mg/dl, p = 0.02). Moreover, in men, the S447X allele conferred significant protection against CHD (odds ratio: 0.43; p = 0.04). These effects on lipids and CHD were not seen in women. Our study represents the first report on the impact of this mutation on CHD in men from the general population, and we conclude, therefore, that the S447X variant may confer significant protection against high TG levels, low HDL-C, and premature CHD in these subjects.

Abstract —Familial hypercholesterolemia (FH) is caused by mutations in the LDL receptor (LDLR) gene and is usually associated with hypercholesterolemia, lipid deposition in tissues, and premature coronary artery disease (CAD). However, individuals with heterozygous FH in China exhibit a milder phenotype despite having deleterious mutations in the LDLR gene (X.-M. Sun et al, Arterioscler Thromb . 1994;14:85–94). Nineteen Chinese FH heterozygotes living in Canada were screened for the 11 mutations that had been described in FH patients living in China. One Chinese Canadian carried one of these mutations (Trp462Stop), 2 carried a previously unreported single-base substitution (Cys163Arg), and 1 carried a mutation observed in French-Canadian patients (Glu207Lys). Twelve additional carriers of these mutations were identified in the families of the index patients. Significantly higher LDL cholesterol concentrations were observed in FH heterozygotes with defined mutations living in Canada (mean±SD, 7.46±1.29, n=16) than in those living in China (4.35±1.09, n=18; P

Abstract Recently, a (t→g) transition at nucleotide −93 in the lipoprotein lipase (LPL) gene promoter has been observed in Caucasians. Here, we have compared the frequency of the −93g carriers in three distinct populations (Caucasians, South African Blacks, and Chinese). The carrier frequency in the Caucasian population was 1.7% (4/232), which was in contrast to the South African Black population, which had a frequency for this allele of 76.4% (123/161) of the individuals tested. This transition was not observed in the Chinese population under study. Near complete linkage disequilibrium between the −93g and the previously described D9N mutation was observed in the Caucasian population but not in South African Blacks. To further assess the ancestral origins of these DNA changes, DNA haplotyping using a CA repeat 5′ to these substitutions was performed. The −93t allele was associated with only a few specific dinucleotide repeat sizes. In contrast, the −93g allele occurred on chromosomes with many different repeat lengths. The broad distribution of repeats on −93g carrying chromosomes, their high frequency in the South African Black population, and the conservation of the −93g allele among different species may suggest that the −93g allele is the ancestral allele on which a transition to t and the D9N mutations arose. The very high frequency of the −93g allele distinct from the N9 allele in a cohort of Black South Africans allowed us to specifically assess the phenotypic effects of the −93g allele on lipids. Individuals homozygous for the g allele at −93 showed mildly decreased triglycerides compared with individuals homozygous for the t allele (1.14±0.66 mmol/L versus 0.82±0.3; P =.04). Thus, the −93g allele in this cohort is associated with low plasma triglyceride levels.

Abstract Familial defective apolipoprotein B-100 (FDB) is a dominantly inherited genetic disorder resulting from a point mutation in the apolipoprotein (apo) B gene and is associated with significantly elevated plasma total and LDL cholesterol levels. Despite numerous descriptions outlining the phenotype of children with familial hypercholesterolemia (FH), no study has described the biochemical and clinical phenotype in a cohort of children with FDB. The phenotypes of FH and FDB, therefore, have not been compared in children. We have studied a cohort of 38 Dutch children (all P P =.001), total cholesterol:HDL ratio ( P P =.001) than age-matched female FH heterozygotes (n=50). Similar results were noted in male FDB carriers (n=15) compared with male FH heterozygotes (n=47; P =.005, P =.007, P =.014, and P =.074, respectively). Within the FDB group, female FDB heterozygotes had higher LDL cholesterol ( P =.038) and a trend to higher total cholesterol levels ( P =.165) than age-matched males. Both male and female FDB carriers had significantly higher total cholesterol, LDL cholesterol, and total cholesterol:HDL ratio than age- and sex-matched control subjects, which was evident even in children

An Asn291Ser mutation in exon 6 of the lipoprotein lipase gene (LPL) frequently occurs in Caucasians (2-4%) and results in a partial catalytic defect. Although this mutation may be associated with low HDL cholesterol and elevated triglyceride levels, some carriers are normolipidemic and may have LPL activity in the normal range in the fasting state. To assess in vivo the influence of dietary stress on the function of this mutation, we have performed oral fat load studies on three unrelated normolipidemic Asn291Ser carriers and compared these results to five healthy controls and to a subject with a clear 50% reduction in LPL activity compared with controls. The Asn291Ser carriers exhibited a more pronounced postprandial response compared with non-carriers as evidenced by higher chylomicron triglyceride (TG) and chylomicron retinyl palmitate peaks (P = 0.03 and P = 0.02, respectively). Significantly higher area under response curves were also seen for both chylomicron triglycerides (P = 0.02) and chylomicron retinyl palmitate (P = 0.01) when compared with non-carriers. These results provide further in vivo evidence for the functional effects of this common mutation despite normal fasting lipid levels. These data suggest that even though subjects with this mutation may be normolipidemic in the fasting state, environmental stress such as an oral fat load may unmask the catalytic defect and result in significant disturbances in postprandial chylomicron metabolism.

Abstract Familial hypercholesterolemia (FH) is characterized by elevated plasma concentrations of LDL cholesterol resulting from mutations in the gene for the LDL receptor. Low HDL cholesterol levels are seen frequently in patients both heterozygous and homozygous for mutations in this gene. Suggested mechanisms for reduced HDL levels in FH patients have been altered apolipoprotein A-1 metabolism and elevated cholesteryl ester transfer protein activity, but the molecular basis for hypoalphalipoproteinemia in any of these patients has not yet been identified. We investigated four large families in which individuals were found to be double heterozygotes for both FH and lipoprotein lipase (LPL) deficiency. These double heterozygotes have significantly less HDL cholesterol than persons with FH or LPL heterozygosity alone. In the double heterozygotes, HDL particle composition is not significantly different from FH heterozygotes, suggesting a quantitative rather than qualitative defect in HDL metabolism in these persons. We propose that mutations in the LPL gene may be a cause of low HDL cholesterol levels in some individuals heterozygous for FH.

Congenital indifference to pain (CIP) is a rare condition in which patients have severely impaired pain perception, but are otherwise essentially normal. We identified and collected DNA from individuals from nine families of seven different nationalities in which the affected individuals meet the diagnostic criteria for CIP. Using homozygosity mapping and haplotype sharing methods, we narrowed the CIP locus to chromosome 2q24-q31, a region known to contain a cluster of voltage-gated sodium channel genes. From these prioritized candidate sodium channels, we identified 10 mutations in the SCN9A gene encoding the sodium channel protein Na v 1.7. The mutations completely co-segregated with the disease phenotype, and nine of these SCN9A mutations resulted in truncation and loss-of-function of the Na v 1.7 channel. These genetic data further support the evidence that Na v 1.7 plays an essential role in mediating pain in humans, and that SCN9A mutations identified in multiple different populations underlie CIP.

Hereditary sensory and autonomic neuropathy (HSAN) type II is an autosomal recessive disorder characterized by impairment of pain, temperature, and touch sensation owing to reduction or absence of peripheral sensory neurons. We identified two large pedigrees segregating the disorder in an isolated population living in Newfoundland and performed a 5-cM genome scan. Linkage analysis identified a locus mapping to 12p13.33 with a maximum LOD score of 8.4. Haplotype sharing defined a candidate interval of 1.06 Mb containing all or part of seven annotated genes, sequencing of which failed to detect causative mutations. Comparative genomics revealed a conserved ORF corresponding to a novel gene in which we found three different truncating mutations among five families including patients from rural Quebec and Nova Scotia. This gene, termed “HSN2,” consists of a single exon located within intron 8 of the PRKWNK1 gene and is transcribed from the same strand. The HSN2 protein may play a role in the development and/or maintenance of peripheral sensory neurons or their supporting Schwann cells.

Background: favorable lipid profiles including low total serum cholesterol (TC), TC/HDL-cholesterol (HDL-C) ratio and elevated HDL-C levels have been previously reported in Chinese living in China. More recent data, however, suggests a changing trend toward decreased HDL-C and increased TC and LDL cholesterol (LDL-C) in Chinese populations. Environmental factors likely contribute, in part, to these findings. However, genetic factors contributing to lipoprotein metabolism may also play a role in determining the lipid/lipoprotein phenotype observed in Chinese populations. Lipoprotein lipase (LPL) mutations have been associated with altered HDL-C concentrations in Caucasians but have not yet been studied in a large population of Chinese descent. Methods: 1577 Chinese Canadians of Cantonese descent were recruited for a cardiovascular risk factor study. The frequency and effect of three LPL gene polymorphisms [Asp9Asn (D9N, n =374), Asn291Ser (N291S, n =321) and Ser447-Ter (S447X, n =403)] on serum HDL-C concentrations was assessed. All the three polymorphisms have been shown to alter HDL-C levels in different Caucasian populations. Results: lower TC, LDL-C, and TG and higher HDL-C were observed in both male and female Chinese Canadian subjects compared to other population samples. The D9N and N291S LPL polymorphisms were identified in 1/374 (0.3%) and 5/321 (1.6%) subjects, respectively. Carrier frequency of the S447X mutation was (102/403) 25.3%. This S447X polymorphism was observed with higher frequency in males with HDL-C levels in the highest tertile compared with those in the lowest HDL-C tertile (carrier frequencies 37.3 vs. 19.4%) ( P =0.046). Conclusion: in this cohort of Chinese Canadians, the serum lipid profiles were more favorable than what has been reported for Caucasian Canadians. A favorable spectrum of polymorphisms in the LPL gene may mitigate the adverse effects of western lifestyle on plasma lipoproteins in this cohort of Cantonese Canadians.

Most studies investigating the symptom dimensions of schizophrenia utilising the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS) favour a three factor model. This study sought to investigate the factor structure of both the global and individual items of the SANS and SAPS in a large sample of South African Xhosa patients with schizophrenia. A total of 422 subjects participated. Both principal components and factor analytical procedures were applied. For the global items, a two-factor solution representing positive and negative symptoms accounted for 59.9% of the variance. Alternatively, the three-dimensional model of negative, psychotic and disorganisation factors was supported by a five-factor solution if the more heterogeneous items of attention and alogia were ignored. Analysis of the individual items yielded a five-factor solution with the negative symptoms splitting into diminished expression and disordered relating, and the positive symptoms separating into factors for psychosis, thought disorder and bizarre behaviour. Our findings are very similar to those from other parts of the world, providing evidence that the factor structure for the symptoms of schizophrenia is relatively resistant to cultural influences. This is particularly true for negative symptoms.

Genes have a major role in the control of high-density lipoprotein (HDL) cholesterol (HDL-C) levels. Here we have identified two Tangier disease (TD) families, confirmed 9q31 linkage and refined the disease locus to a limited genomic region containing the gene encoding the ATP-binding cassette transporter (ABC1). Familial HDL deficiency (FHA) is a more frequent cause of low HDL levels. On the basis of independent linkage and meiotic recombinants, we localized the FHA locus to the same genomic region as the TD locus. Mutations in ABC1 were detected in both TD and FHA, indicating that TD and FHA are allelic. This indicates that the protein encoded by ABC1 is a key gatekeeper influencing intracellular cholesterol transport, hence we have named it cholesterol efflux regulatory protein (CERP).

Summary Background A low concentration of HDL cholesterol is the most common lipoprotein abnormality in patients with premature atherosclerosis. We have shown that Tangier disease, a rare and severe form of HDL deficiency characterised by a biochemical defect in cellular cholesterol efflux, is caused by mutations in the ATP-binding-cassette ( ABC1 ) gene. This gene codes for the cholesterol-efflux regulatory protein (CERP). We investigated the presence of mutations in this gene in patients with familial HDL deficiency. Methods Three French-Canadian families and one Dutch family with familial HDL deficiency were studied. Fibroblasts from the proband of each family were defective in cellular cholesterol efflux. Genomic DNA of each proband was used for mutation detection with primers flanking each exon of the ABC 1 gene, and for sequencing of the entire coding region of the gene. PCR and restriction-fragment length polymorphism assays specific to each mutation were used to investigate segregation of the mutation in each family, and to test for absence of the mutation in DNA from normal controls. Findings A different mutation was detected in ABC1 in each family studied. Each mutation either created a stop codon predicted to result in truncation of CERP, or altered a conserved aminoacid residue. Each mutation segregated with low concentrations of HDL-cholesterol in the family, and was not observed in more than 500 control chromosomes tested. Interpretation These data show that mutations in ABC 1 are the major cause of familial HDL deficiency associated with defective cholesterol efflux, and that CERP has an essential role in the formation of HDL. Our findings highlight the potential of modulation of ABC 1 as a new route for increasing HDL concentrations.

Background —Recently, a mutation in the lipoprotein lipase (LPL) gene (N291S) has been reported in 2% to 5% of individuals in western populations and is associated with increased triglyceride (TG) and reduced HDL cholesterol (HDLC) concentrations. Methods and Results —Here we report a significant alteration in biochemical and clinical phenotype in subjects with familial hypercholesterolemia (FH) who are heterozygous for this N291S LPL mutation. Sixty-four FH heterozygotes carrying the N291S mutation had significantly a higher TG level ( P =.004), a higher ratio of total cholesterol to HDLC ( P P =.002) compared with 175 FH heterozygotes without this LPL mutation. Moreover, the N291S mutation conferred a significantly greater risk for developing cardiovascular disease in FH heterozygotes compared with FH heterozygotes without this LPL mutation (odds ratio, 3.875; P =.006). Conclusions —These data provide evidence that a common LPL variant (N291S) significantly influences the biochemical phenotype and risk for cardiovascular disease in patients with FH.

Familial defective apo B-100 (FDB) is an autosomal dominant condition resulting in hypercholesterolemia. It is generally observed in 1–6% of hypercholesterolemic subjects in Caucasian populations studied. There are, thus far, no reports characterizing the frequency and phenotype of FDB in a Chinese population. We report on the frequency of the FDB (Arg (3500) →Gln) mutation and the associated haplotype among 160 hypercholesterolemic (TC≥6.2 mmol/l) Chinese Canadians including 36 subjects with a clinical diagnosis of familial hypercholesterolemia (FH). Screening for the FDB mutation was done using a mutagenic polymerase chain reaction and haplotype analysis was undertaken using eight diallelic markers and the 3′HVR marker. One Chinese Canadian clinical FH heterozygote was positive for the FDB Arg (3500) →Gln mutation while none of the remaining non-FH hypercholesterolemic subjects ( n =124) were carriers of this mutation. Haplotype analysis in the patient positive for this mutation revealed a unique haplotype which differed from both the common haplotype of this mutation observed in Caucasians and from the only other haplotype reported in a Chinese individual. The associated haplotype included a 9-base pair deletion in the signal peptide region and the presence of three restriction sites absent in previously reported haplotypes. These data suggest that the apo B-100 Arg (3500) →Gln mutation does not appear to be a significant factor contributing to moderate hypercholesterolemia in a Chinese population residing in Canada. However, this mutation was rarely observed among Chinese individuals with a clinical diagnosis of FH. The presence among Chinese individuals of two different haplotypes associated with this mutation, which are different from what has been described among Caucasians is compatible with multiple recurrent origins for this mutation in the Chinese population.