Epilepsy, impaired functioning, and quality of life in patients with tuberous sclerosis complex.

OBJECTIVE: To estimate health-related quality of life (HRQoL) in patients with tuberous sclerosis complex (TSC) and associated manifestations and to identify potential factors associated with HRQoL in this population of patients. METHODS: We performed a retrospective chart review of adults with TSC who attended the outpatient clinic of the University Medical Center Utrecht in the Netherlands from 1990 to 2015 (N = 363; on average 33.6 years of follow-up). HRQoL data were assessed in 2012 using the Health Utility Index version 3 (HUI-3) questionnaire completed by patients or caregivers (N = 214 with HUI score and ≥1 TSC manifestation, including renal angiomyolipomas [rAMLs], subependymal giant cell astrocytoma [SEGA], or epilepsy). RESULTS: Of 214 patients in the study sample, 171 had TSC-associated epilepsy (with or without rAML/SEGA), 37 had TSC and rAML (without epilepsy or SEGA), and 6 had other combinations of manifestations. The median HUI score for the 214 patients with ≥1 TSC manifestation was 0.51 (-0.371 to 1 scale, 1 = perfect health, 0 = death, <0 = worse than death). Among all components used to build the overall HUI score, the cognition component had the lowest score (mean = 0.47; 0-1 scale). Patients with TSC-epilepsy had significantly lower overall HUI than patients with TSC and rAML only (median HUI = 0.31 vs 0.95, P < .05), especially those who were in refractory state for prolonged periods of time (median HUI = -0.11 among patients with seizures during the entire duration of their follow-up time). In multivariate analyses, severe impairment of daily functioning was the strongest predictor of HRQoL decrement (adjusted HUI difference between patients with severe vs. no impairment = -0.55, P < .05). SIGNIFICANCE: This study showed that TSC-related epilepsy is associated with lower HUI, especially for patients who have refractory seizures for prolonged periods of time. Early and effective interventions to control or reduce seizures and preserve patients' cognitive functions may help to improve patients' quality of life.

Well-differentiated Pancreatic Neuroendocrine Tumor in a Patient With Familial Atypical Multiple Mole Melanoma Syndrome (FAMMM).

Germline mutations in CDKN2A result in Familial Atypical Multiple Mole Melanoma Syndrome (FAMMM), which is associated with an increased risk for pancreatic ductal adenocarcinoma and melanoma. CDKN2A is somatically inactivated in multiple neoplasms, raising the possibility that, although the data are not conclusive, germline CDKN2A mutation may also impose an increased risk for other neoplasms. We present a patient with a CDKN2A germline mutation (p16-Leiden mutation) and mosaicism for neurofibromatosis type 2, who presented with a small asymptomatic pancreatic lesion, detected during endoscopic ultrasound screening of the pancreas. After resection, the lesion was found to be a well-differentiated pancreatic neuroendocrine tumor (PanNET). Molecular analysis of the tumor showed somatic loss of the second allele, supporting a causal relation of the PanNET to the underlying FAMMM syndrome. Recent data, showing the association between certain single-nucleotide polymorphisms in the CDKN2A gene and an increased incidence for PanNET, further support a role for germline CDKN2A alterations in PanNET risk. We conclude that PanNETs can be a phenotypic expression of FAMMM syndrome. This can have implications for screening and for the diagnosis of pancreatic neoplasms in carriers of germline CDKN2A mutations.

Risk of breast cancer in patients with lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is a rare metastasizing pulmonary disease that shares some clinical, cellular, and molecular similarities with metastatic breast cancer to lung. LAM cells have been identified circulating in various body fluids of patients and, intriguingly, diverse evidence indicates that these cells may originate from a different organ to the lung. Following on from these observations, we hypothesized the existence of a common risk basis between LAM and breast cancer, and suggested increased risk of breast cancer among LAM patients. Here, by studying two additional LAM cohorts with more detailed epidemiological, life-style, and disease-related data, we show consistent results; a potential excess of estrogen-receptor-positive young breast cancer cases in LAM. This observation further suggests the need of prospective studies to precisely assess the association between both diseases.

Tuberous sclerosis complex: Concerns and needs of patients and parents from the transitional period to adulthood.

INTRODUCTION: Transitioning into adulthood and from pediatric services to adult healthcare are both challenging processes for young adults with rare chronic disorders such as tuberous sclerosis complex (TSC) and their parents. Adult healthcare systems are often less family-oriented and lack multidisciplinary care and experience with TSC, which can result in increased health risks and morbidity. Patient-driven data on care needs are necessary to optimize support for this vulnerable patient group. AIM: The aim of this study was to explore the concerns and care needs of young adult patients with TSC in medical, psychological, and socioeconomical domains. METHOD: A qualitative study was performed using semistructured interviews with 16 patients (median age: 21years; range: 17 to 30) and 12 parents. Concerns and care needs were organized using the International Classification of Functioning, Disability, and Health (ICF). RESULTS: Main concerns involved mental and physical health, participation, self-management skills, family planning, and side effects of medications. Patients expressed the need for multidisciplinary care that is well-informed, easily accessible, and focused on the patient as a whole, including his/her family. Parents reported high stress levels. CONCLUSION: The current study provides patient-driven information, allowing recommendations to facilitate the (transition of) care for young adults with TSC. In addition to seizures, tumor growth, and TSC-associated neuropsychiatric disorders (TAND), more attention is needed for concerns and care needs specific to the transitional period, participation, and environmental factors. Adult healthcare providers should offer expert multidisciplinary care for adult patients with TSC, including attention for parental stress.

Persistent Hepatitis E Infection in a Patient with Tuberous Sclerosis Complex Treated with Everolimus: A Case Report.

INTRODUCTION: The incidence of hepatitis E (HEV) genotype 3 is rising in developed countries. HEV infections are usually self-limiting, but can become chronic in immunocompromised patients. This might lead to rapid fibrosis development even resulting in cirrhosis. Chronic HEV is mainly described in patients after solid-organ or hematological transplantations. We present the first case of HEV infection in a patient with tuberous sclerosis complex (TSC) treated with everolimus, a mammalian target of rapamycin (mTOR) inhibitor. CASE: A 46-year-old male with TSC was referred to the infectious diseases department with an acute rise of liver enzymes during routine laboratory check-up. He was diagnosed with an acute HEV infection. His current treatment for TSC was everolimus. After awaiting a spontaneous clearance for 3 months, everolimus was discontinued. Hereafter, the infection was cleared within another 3 months. DISCUSSION: Due to a favorable side-effect profile, everolimus is gaining popularity as an immunosuppressive therapy. However, in vitro experiments suggest that inhibition of mTOR leads to a significant increase in HEV replication. Thus far, there have been no clinical reports of HEV infections in patients treated with everolimus. CONCLUSION: Due to higher dosing of everolimus in TSC patients, they are more vulnerable to the development of chronic HEV infection. Periodic assessment of transaminases in these patients is advised.

Lipoprotein profiles in human heterozygote carriers of a functional mutation P297S in scavenger receptor class B1.

The scavenger receptor class B type 1 (SR-B1) is an important HDL receptor involved in cholesterol uptake and efflux, but its physiological role in human lipoprotein metabolism is not fully understood. Heterozygous carriers of the SR-B1(P297S) mutation are characterized by increased HDL cholesterol levels, impaired cholesterol efflux from macrophages and attenuated adrenal function. Here, the composition and function of lipoproteins were studied in SR-B1(P297S) heterozygotes.Lipoproteins from six SR-B1(P297S) carriers and six family controls were investigated. HDL and LDL/VLDL were isolated by ultracentrifugation and proteins were separated by two-dimensional gel electrophoresis and identified by mass spectrometry. HDL antioxidant properties, paraoxonase 1 activities, apoA-I methionine oxidations and HDL cholesterol efflux capacity were assessed.Multivariate modeling separated carriers from controls based on lipoprotein composition. Protein analyses showed a significant enrichment of apoE in LDL/VLDL and of apoL-1 in HDL from heterozygotes compared to controls. The relative distribution of plasma apoE was increased in LDL and in lipid-free form. There were no significant differences in paraoxonase 1 activities, HDL antioxidant properties or HDL cholesterol efflux capacity but heterozygotes showed a significant increase of oxidized methionines in apoA-I.The SR-B1(P297S) mutation affects both HDL and LDL/VLDL protein compositions. The increase of apoE in carriers suggests a compensatory mechanism for attenuated SR-B1 mediated cholesterol uptake by HDL. Increased methionine oxidation may affect HDL function by reducing apoA-I binding to its targets. The results illustrate the complexity of lipoprotein metabolism that has to be taken into account in future therapeutic strategies aiming at targeting SR-B1.

In vivo tissue cholesterol efflux is reduced in carriers of a mutation in APOA1.

Atheroprotection by high density lipoprotein (HDL) is considered to be mediated through reverse cholesterol transport (RCT) from peripheral tissues. We investigated in vivo cholesterol fluxes through the RCT pathway in patients with low plasma high density lipoprotein cholesterol (HDL-c) due to mutations in APOA1. Seven carriers of the L202P mutation in APOA1 (mean HDL-c: 20 ± 19 mg/dl) and seven unaffected controls (mean HDL-c: 54 ± 11 mg/dl, P < 0.0001) received a 20 h infusion of (13)C2-cholesterol ((13)C-C). Enrichment of plasma and erythrocyte free cholesterol and plasma cholesterol esters was measured. With a three-compartment SAAM-II model, tissue cholesterol efflux (TCE) was calculated. TCE was reduced by 19% in carriers (4.6 ± 0.8 mg/kg/h versus 5.7 ± 0.7 mg/kg/h in controls, P = 0.02). Fecal (13)C recovery and sterol excretion 7 days postinfusion did not differ significantly between carriers and controls: 21.3 ± 20% versus 13.3 ± 6.3% (P = 0.33), and 2,015 ± 1,431 mg/day versus 1456 ± 404 mg/day (P = 0.43), respectively. TCE is reduced in carriers of mutations in APOA1, suggesting that HDL contributes to efflux of tissue cholesterol in humans. The residual TCE and unaffected fecal sterol excretion in our severely affected carriers suggest, however, that non-HDL pathways contribute to RCT significantly.

Genetic variant of the scavenger receptor BI in humans.

BACKGROUND: In mice, the scavenger receptor class B type I (SR-BI) is essential for the delivery of high-density lipoprotein (HDL) cholesterol to the liver and steroidogenic organs. Paradoxically, elevated HDL cholesterol levels are associated with increased atherosclerosis in SR-BI-knockout mice. It is unclear what role SR-BI plays in human metabolism. METHODS: We sequenced the gene encoding SR-BI in persons with elevated HDL cholesterol levels and identified a family with a new missense mutation (P297S). The functional effects of the P297S mutation on HDL binding, cellular cholesterol uptake and efflux, atherosclerosis, platelet function, and adrenal function were studied. RESULTS: Cholesterol uptake from HDL by primary murine hepatocytes that expressed mutant SR-BI was reduced to half of that of hepatocytes expressing wild-type SR-BI. Carriers of the P297S mutation had increased HDL cholesterol levels (70.4 mg per deciliter [1.8 mmol per liter], vs. 53.4 mg per deciliter [1.4 mmol per liter] in noncarriers; P<0.001) and a reduced capacity for efflux of cholesterol from macrophages, but the carotid artery intima-media thickness was similar in carriers and in family noncarriers. Platelets from carriers had increased unesterified cholesterol content and impaired function. In carriers, adrenal steroidogenesis was attenuated, as evidenced by decreased urinary excretion of sterol metabolites, a decreased response to corticotropin stimulation, and symptoms of diminished adrenal function. CONCLUSIONS: We identified a family with a functional mutation in SR-BI. The mutation carriers had increased HDL cholesterol levels and a reduction in cholesterol efflux from macrophages but no significant increase in atherosclerosis. Reduced SR-BI function was associated with altered platelet function and decreased adrenal steroidogenesis. (Funded by the European Community and others.).

C-reactive protein is a mediator of cardiovascular disease.

C-reactive protein is postulated to embody an index that can reflect cardiovascular risk and can be used to independently predict major cardiovascular events and mortality. On the other hand, credible experimental data have become available that demonstrate the abundant presence of C-reactive protein in atherosclerotic lesions and, moreover, identify C-reactive protein as an initiator of several pathogenic pathways that can cause atherogenic changes. Consequently, there has been a paradigm shift in which C-reactive protein is no longer regarded as merely an indicator of cardiovascular risk, but increasingly considered a direct partaker in the pathogenesis of atherosclerotic cardiovascular disease. These data underscore the need to explore risk-reducing interventions that selectively inhibit C-reactive protein activity as a novel strategy to prevent clinical manifestations of atherosclerosis.

Genetic variation at the phospholipid transfer protein locus affects its activity and high-density lipoprotein size and is a novel marker of cardiovascular disease susceptibility.

BACKGROUND: In contrast to clear associations between variants in genes participating in low-density lipoprotein metabolism and cardiovascular disease risk, such associations for high-density lipoprotein (HDL)-related genes are not well supported by recent large studies. We aimed to determine whether genetic variants at the locus encoding phospholipid transfer protein (PLTP), a protein involved in HDL remodeling, underlie altered PLTP activity, HDL particle concentration and size, and cardiovascular disease risk. METHODS AND RESULTS: We assessed associations between 6 PLTP tagging single nucleotide polymorphisms and PLTP activity in 2 studies (combined n=384) and identified 2 variants that show reproducible associations with altered plasma PLTP activity. A gene score based on these variants is associated with lower hepatic PLTP transcription (P=3.2x10(-18)) in a third study (n=957) and with an increased number of HDL particles of smaller size (P=3.4x10(-17)) in a fourth study (n=3375). In a combination of 5 cardiovascular disease case-control studies (n=4658 cases and 11 459 controls), a higher gene score was associated with a lower cardiovascular disease risk (per-allele odds ratio, 0.94; 95% confidence interval, 0.90 to 0.98; P=1.2x10(-3); odds ratio for highest versus lowest gene score, 0.69; 95% confidence interval, 0.55 to 0.86; P=1.0x10(-3)). CONCLUSIONS: A gene score based on 2 PLTP single nucleotide polymorphisms is associated with lower PLTP transcription and activity, an increased number of HDL particles, smaller HDL size, and decreased risk of cardiovascular disease. These findings indicate that PLTP is a proatherogenic entity and suggest that modulation of specific elements of HDL metabolism may offer cardiovascular benefit.

Lack of association between common genetic variation in endothelial lipase (LIPG) and the risk for CAD and DVT.

OBJECTIVES: Low levels of high-density lipoprotein cholesterol (HDL-C) are a risk factor for coronary artery disease (CAD) and possibly for deep venous thrombosis (DVT). Endothelial lipase is involved in HDL-C metabolism. Common variants in the endothelial lipase gene (LIPG) have been reported to be associated with HDL-C levels and atherothrombosis, but these findings were not consistent. We determined whether five tagging single nucleotide polymorphisms (SNP) in LIPG were associated with lipid parameters, the risk of CAD and the risk of DVT. METHODS: We used the prospective case-control study nested in the EPIC-Norfolk cohort (1138 CAD cases, 2237 matched controls) for the initial association study and, subsequently, the ACT study (185 patients with documented DVT, 586 patients in which DVT was ruled out) to replicate our findings regarding DVT risk. RESULTS: In EPIC-Norfolk, we found that the minor allele of one SNP, rs2000813 (p.T111I), was associated with moderately higher HDL-C and apolipoprotein A-I levels, higher HDL particle number and larger HDL size. No variants were associated with CAD risk, but three variants were associated with DVT risk (odds ratios 0.60 [95%CI 0.43-0.84], 2.04 [95%CI 1.40-2.98] and 1.67 [95%CI 1.18-2.38] per minor allele for rs2000813, rs6507931 and rs2097055 respectively, p<0.005 for each). However, the association between LIPG SNPs and DVT risk could not be replicated in the ACT study. CONCLUSIONS: Our data support a modest association between the LIPG rs2000813 variant and parameters of HDL metabolism, but no association between common genetic variants in LIPG and CAD or DVT risk.

Carotid atherosclerosis progression in familial hypercholesterolemia patients: a pooled analysis of the ASAP, ENHANCE, RADIANCE 1, and CAPTIVATE studies.

BACKGROUND: Until recently, patients with heterozygous familial hypercholesterolemia (HeFH) were considered the best subjects for the assessment of changes in carotid intima-media thickness (cIMT) in randomized intervention trials. Our aims were to investigate whether contemporary statin-treated HeFH patients still show accelerated cIMT increase and to assess the impact of statin treatment, before and after random assignment, on atherosclerosis progression. METHODS AND RESULTS: We retrospectively evaluated cIMT change, and prior statin treatment and postbaseline LDL-C change as predictors of cIMT change, in 1513 HeFH patients who were randomly assigned to the statin arms of the early ASAP and more recent RADIANCE 1, CAPTIVATE, and ENHANCE studies. In the 3 recent studies combined, mean cIMT increased at only 33%of the rate of the simvastatin-treated patients in the ASAP study (0.014 mm/2 years [95% confidence interval, -0.0003-0.028] versus 0.041 mm/2 years [95% confidence interval, 0.020-0.061]; P<0.05). Patients whose statin therapy could be intensified, as evidenced by an LDL-C decrease after the initiation of on-trial statin therapy, showed cIMT decrease in the first 6 to 12 months and a much lower cIMT increase measured over the full 2 years. In line with this, previously statin-naive HeFH patients showed a lower overall cIMT increase. CONCLUSIONS: Over the years, intensification of statin therapy in HeFH patients has resulted in an impressive decrease in carotid atherosclerosis progression. In studies that assess other antiatherosclerotic modalities, statin therapy may still induce rapid changes in cIMT. For future cIMT studies, our analyses suggest that patient populations other than intensively pretreated HeFH patients should be selected and that the statin regimen should not be changed on study initiation.

The HDL hypothesis: does high-density lipoprotein protect from atherosclerosis?

There is unequivocal evidence of an inverse association between plasma high-density lipoprotein (HDL) cholesterol concentrations and the risk of cardiovascular disease, a finding that has led to the hypothesis that HDL protects from atherosclerosis. This review details the experimental evidence for this "HDL hypothesis". In vitro studies suggest that HDL has a wide range of anti-atherogenic properties but validation of these functions in humans is absent to date. A significant number of animal studies and clinical trials support an atheroprotective role for HDL; however, most of these findings were obtained in the context of marked changes in other plasma lipids. Finally, genetic studies in humans have not provided convincing evidence that HDL genes modulate cardiovascular risk. Thus, despite a wealth of information on this intriguing lipoprotein, future research remains essential to prove the HDL hypothesis correct.

Carriers of loss-of-function mutations in ABCA1 display pancreatic beta-cell dysfunction.

OBJECTIVE: Abnormal cellular cholesterol handling in islets may contribute to beta-cell dysfunction in type 2 diabetes. beta-Cell deficiency for the ATP binding cassette transporter A1 (ABCA1), which mediates the efflux of cellular cholesterol, leads to altered intracellular cholesterol homeostasis and impaired insulin secretion in mice. We aimed to assess the impact of ABCA1 dysfunction on glucose homeostasis in humans. RESEARCH DESIGN AND METHODS: In heterozygous carriers of disruptive mutations in ABCA1 and family-based noncarriers of similar age, sex, and BMI, we performed oral glucose tolerance tests (OGTTs) (n = 15 vs. 14) and hyperglycemic clamps (n = 8 vs. 8). RESULTS: HDL cholesterol levels in carriers were less than half those in noncarriers, but LDL cholesterol levels did not differ. Although fasting plasma glucose was similar between groups, glucose curves after an OGTT were mildly higher in carriers than in noncarriers. During hyperglycemic clamps, carriers demonstrated lower first-phase insulin secretion than noncarriers but no difference in insulin sensitivity. The disposition index (a measure of beta-cell function adjusted for insulin sensitivity) of the carriers was significantly reduced in ABCA1 heterozygotes. CONCLUSIONS: Carriers of loss-of-function mutations in ABCA1 show impaired insulin secretion without insulin resistance. Our data provide evidence that ABCA1 is important for normal beta-cell function in humans.

The pharmacology and off-target effects of some cholesterol ester transfer protein inhibitors.

Inhibitors of cholesterol ester transfer protein (CETP) have the capacity to increase plasma high-density lipoprotein cholesterol to unprecedented levels. Still, hopes that CETP inhibition could reduce atherosclerosis were dented when the clinical development of one such inhibitor, torcetrapib, was halted because of an unexpected finding of increased cardiovascular and noncardiovascular mortality against a background of elevated blood pressure and plasma aldosterone levels. Recently, evidence has accumulated to show that these untoward effects may have been largely attributable to off-target toxicity of the compound, unrelated to the mechanism of CETP inhibition and not shared by other CETP inhibitors. In this review, we explore the rationale for CETP inhibition, compare the pharmacology of the small molecule CETP inhibitors that reached clinical development, and address the evidence relating to off-target adverse effects.

Both paraoxonase-1 genotype and activity do not predict the risk of future coronary artery disease; the EPIC-Norfolk Prospective Population Study.

BACKGROUND: Paraoxonase-1 (PON1) is an antioxidant enzyme, that resides on high-density lipoprotein (HDL). PON1-activity, is heavily influenced by the PON1-Q192R polymorphism. PON1 is considered to protect against atherosclerosis, but it is unclear whether this relation is independent of its carrier, HDL. In order to evaluate the atheroprotective potential of PON1, we assessed the relationships among PON1-genotype, PON1-activity and risk of future coronary artery disease (CAD), in a large prospective case-control study. METHODOLOGY/PRINCIPAL FINDINGS: Cases (n = 1138) were apparently healthy men and women aged 45-79 years who developed fatal or nonfatal CAD during a mean follow-up of 6 years. Controls (n = 2237) were matched by age, sex and enrollment time. PON1-activity was similar in cases and controls (60.7+/-45.3 versus 62.6+/-45.8 U/L, p = 0.3) and correlated with HDL-cholesterol levels (r = 0.16, p<0.0001). The PON1-Q192R polymorphism had a profound impact on PON1-activity, but did not predict CAD risk (Odds Ratio [OR] per R allele 0.98[0.84-1.15], p = 0.8). Using conditional logistic regression, quartiles of PON1-activity showed a modest inverse relation with CAD risk (OR for the highest versus the lowest quartile 0.77[0.63-0.95], p = 0.01; p-trend = 0.06). PON1-activity adjusted for Q192R polymorphism correlated better with HDL-cholesterol (r = 0.26, p<0.0001) and more linearly predicted CAD risk (0.79[0.64-0.98], p = 0.03; p-trend = 0.008). However, these relationships were abolished after adjustment for HDL (particles-cholesterol-size) and apolipoproteinA-I (0.94[0.74-1.18], p-trend = 0.3). CONCLUSIONS/SIGNIFICANCE: This study, shows that PON1-activity inversely relates to CAD risk, but not independent of HDL, due to its close association with the HDL-particle. These data strongly suggest that a low PON1-activity is not a causal factor in atherogenesis.

Cholesteryl ester transfer protein inhibitor torcetrapib and off-target toxicity: a pooled analysis of the rating atherosclerotic disease change by imaging with a new CETP inhibitor (RADIANCE) trials.

BACKGROUND: Torcetrapib, an inhibitor of cholesteryl ester transfer protein, has been shown to increase the cardiovascular event rate despite conferring a significant high-density lipoprotein cholesterol increase. Using data from the Rating Atherosclerotic Disease Change by Imaging with a New CETP Inhibitor [corrected] (RADIANCE) trials, which assessed the impact of torcetrapib on carotid intima-media thickness (cIMT), we sought to explore potential mechanisms underlying this adverse outcome. METHODS AND RESULTS: Data from the RADIANCE 1 and 2 studies, which examined cIMT in 904 subjects with familial hypercholesterolemia and in 752 subjects with mixed dyslipidemia, were pooled. Subjects were randomized to either atorvastatin or torcetrapib combined with atorvastatin. Mean common cIMT progression was increased in subjects receiving torcetrapib plus atorvastatin compared with subjects receiving atorvastatin alone (0.0076+/-0.0011 versus 0.0025+/-0.0011 mm/y; P=0.0014). Subjects treated with torcetrapib plus atorvastatin displayed higher postrandomization systolic blood pressure and plasma sodium and bicarbonate levels in conjunction with lower potassium levels. The decrease in potassium levels was associated with the blood pressure increase. Markedly, the use of renin-angiotensin-aldosterone system inhibitors tended to aggravate the blood pressure increase. Subjects receiving torcetrapib plus atorvastatin with the strongest low-density lipoprotein cholesterol reduction showed the smallest cIMT progression, whereas subjects with the highest systolic blood pressure increase showed the largest cIMT progression. High-density lipoprotein cholesterol increase was not associated with cIMT change. CONCLUSIONS: These analyses support mineralocorticoid-mediated off-target toxicity in patients receiving torcetrapib as a contributing factor to an adverse outcome. The absence of an inverse relationship between high-density lipoprotein cholesterol change and cIMT progression suggests that torcetrapib-induced high-density lipoprotein cholesterol increase does not mediate atheroprotection. Future studies with cholesteryl ester transfer protein inhibitors without off-target toxicity are needed to settle this issue.

The value of HDL genetics.

PURPOSE OF REVIEW: To review studies on hereditary disorders of high-density lipoprotein (HDL) metabolism and studies on HDL genetics in mice, which have both provided valuable insight into the pathways of this intriguing lipoprotein and moreover revealed targets to raise HDLc to reduce atherosclerosis. RECENT FINDINGS: To date, as many as 11 genes are considered key players in the synthesis, maturation, conversion and/or catabolism of HDL. Five of these genes have been identified in humans, APOA1, LCAT, ABCA1, LIPC, and CETP, whereas the other six genes have been identified in mice, SCARB1, ABCG1, ATPB5, PLTP, LIPG and APOM. Genetic association studies are as yet the best line of evidence of the roles of the 'murine genes' in human HDL pathways. In addition to recent genetic association studies, a third section describes exciting news on six newly proposed HDL genes VNN1, GALNT2, MMAB/MVK, CTalpha, BMP-1 and SIRT1. SUMMARY: This review provides a summary of the current literature on the genetics of HDL. New information from this research area may assist us in obtaining a better understanding of HDL biology and identifying novel pharmacological targets.