Knowns and unknowns in the care of pediatric familial hypercholesterolemia

Algorithm for detection and screening of familial hypercholesterolemia in Lithuanian population

BACKGROUND

Familial hypercholesterolemia (FH) is one of the most common autosomal dominant diseases. FH causes a lifelong increase in low-density lipoprotein cholesterol (LDL-C) levels, which in turn leads to atherosclerotic cardiovascular disease. The incidence of FH is widely underestimated and undertreated, despite the availability and effectiveness of lipid-lowering therapy. Patients with FH have an increased cardiovascular risk; therefore, early diagnosis and treatment are vital. To address the burden of FH, several countries have implemented national FH screening programmes. The currently used method for FH detection in Lithuania is mainly based on opportunistic testing with subsequent cascade screening of index cases' first-degree relatives.

METHODS

A total of 428 patients were included in this study. Patients with suspected FH are referred to a lipidology center for thorough evaluation. Patients who met the criteria for probable or definite FH according to the Dutch Lipid Clinic Network (DLCN) scoring system and/or had LDL-C > = 6.5 mmol/l were subjected to genetic testing. Laboratory and instrumental tests, vascular marker data of early atherosclerosis, and consultations by other specialists, such as radiologists and ophthalmologists, were also recorded.

RESULTS

A total of 127/428 (30%) patients were genetically tested. FH-related mutations were found in 38.6% (n = 49/127) of the patients. Coronary artery disease (CAD) was diagnosed in 13% (n = 57/428) of the included patients, whereas premature CAD was found in 47/428 (11%) patients. CAD was diagnosed in 19% (n = 9/49) of patients with FH-related mutations, and this diagnosis was premature for all of them.

CONCLUSIONS

Most patients in this study were classified as probable or possible FH without difference of age and sex. The median age of FH diagnosis was 47 years with significantly older females than males, which refers to the strong interface of this study with the LitHir programme. CAD and premature CAD were more common among patients with probable and definite FH, as well as those with an FH-causing mutation. The algorithm described in this study is the first attempt in Lithuania to implement a specific tool which allows to maximise FH detection rates, establish an accurate diagnosis of FH, excluding secondary causes of dyslipidaemia, and to select patients for cascade screening initiation more precisely.

Dyslipidaemia as a target for atherosclerotic cardiovascular disease prevention in children with type 1 diabetes: lessons learned from familial hypercholesterolaemia

In the last few decades, atherosclerotic cardiovascular disease (ASCVD) risk has decreased dramatically among individuals affected by familial hypercholesterolaemia (FH) as a result of the early initiation of statin treatment in childhood. Contemporaneously important improvements in care for people with diabetes have also been made, such as the prevention of mortality from acute diabetic complications. However, individuals with type 1 diabetes still have a two to eight times higher risk of death than the general population. In the last 20 years, a few landmark studies on excess mortality in people with type 1 diabetes, in particular young adults, have been published. Although these studies were carried out in different populations, all reached the same conclusion: individuals with type 1 diabetes have a pronounced increased risk of ASCVD. In this review, we address the role of lipid abnormalities in the development of ASCVD in type 1 diabetes and FH. Although type 1 diabetes and FH are different diseases, lessons could be learned from the early initiation of statins in children with FH, which may provide a rationale for more stringent control of dyslipidaemia in children with type 1 diabetes.

International Atherosclerosis Society guidance for implementing best practice in the care of familial hypercholesterolaemia

This contemporary, international, evidence-informed guidance aims to achieve the greatest good for the greatest number of people with familial hypercholesterolaemia (FH) across different countries. FH, a family of monogenic defects in the hepatic LDL clearance pathway, is a preventable cause of premature coronary artery disease and death. Worldwide, 35 million people have FH, but most remain undiagnosed or undertreated. Current FH care is guided by a useful and diverse group of evidence-based guidelines, with some primarily directed at cholesterol management and some that are country-specific. However, none of these guidelines provides a comprehensive overview of FH care that includes both the lifelong components of clinical practice and strategies for implementation. Therefore, a group of international experts systematically developed this guidance to compile clinical strategies from existing evidence-based guidelines for the detection (screening, diagnosis, genetic testing and counselling) and management (risk stratification, treatment of adults or children with heterozygous or homozygous FH, therapy during pregnancy and use of apheresis) of patients with FH, update evidence-informed clinical recommendations, and develop and integrate consensus-based implementation strategies at the patient, provider and health-care system levels, with the aim of maximizing the potential benefit for at-risk patients and their families worldwide.

Integrated guidance to enhance the care of children and adolescents with familial hypercholesterolaemia: Practical advice for the community clinician

Familial hypercholesterolaemia (FH) is a highly penetrant monogenic disorder present from birth that markedly elevates plasma low-density lipoprotein (LDL)-cholesterol (LDL-C) concentration and, if untreated, leads to premature atherosclerosis and coronary artery disease (CAD). At a prevalence of 1:250 individuals, with over 90% undiagnosed, recent estimates suggest that there are approximately 22 000 children and adolescents with FH in Australia and New Zealand. However, the overwhelming majority remain undetected and inadequately treated until adulthood or after their first cardiac event. The guidance in this paper aims to increase awareness about paediatric FH and provide practical advice for the diagnosis and management of FH in children and adolescents. Recommendations are given on the detection, diagnosis, assessment and management of FH in children and adolescents. Recommendations are also made on genetic testing, including counselling and the potential for universal screening programmes. Practical guidance on management includes treatment of non-cholesterol risk factors, and safe and appropriate use of LDL-C lowering therapies, including statins, ezetimibe, PCSK9 inhibitors and lipoprotein apheresis. Models of care for FH need to be adapted to local and regional health care needs and available resources. Targeting the detection of FH as a priority in children and young adults has the potential to alter the natural history of atherosclerotic cardiovascular disease and recognise the promise of early detection for improving long-term health outcomes. A comprehensive implementation strategy, informed by further research, including assessments of cost-benefit, will be required to ensure that this new guidance benefits all families with or at risk of FH.

Recent Advances on Familial Hypercholesterolemia in Children and Adolescents

Familial hypercholesterolemia is a common autosomal hereditary disorder characterized by elevated concentrations of low-density lipoprotein cholesterol and the development of premature atherosclerosis and cardiovascular disease. Early diagnosis, as well as prompt and aggressive treatment, are fundamental steps to prevent cardiovascular complications and a high rate of premature mortality in children and adolescents. Clinics and genetics are the two main aspects on which diagnosis is based. Widespread screening programs are a respectable option for the early detection of familial hypercholesterolemia. Different types of screening have been proposed so far; however, the optimal screening program has not yet been found. The treatment approach for both heterozygous and homozygous familial hypercholesterolemia in the pediatric population is multidisciplinary, including lifestyle modifications, standard lipid-lowering medications, and novel pharmacological agents. The latter show promising results, especially for patients who experience intolerance to other treatment or present with more severe conditions. Our purpose is to focus on the importance of the early detection of familial hypercholesterolemia, and to highlight the best therapeutic strategies, including the recent approaches based on current clinical evidence, that need to be adopted from the earliest stages of life.

A Selective Screening Strategy Performed in Pre-School Children and Siblings to Detect Familial Hypercholesterolemia

(1) Background: Familial hypercholesterolemia (FH), a most common genetic disorder, is underdiagnosed and untreated, especially in children. Individuals with heterozygous familial hypercholesterolemia mostly present without clinical symptoms and are not informed about their high risk for myocardial infarction. Early diagnosis and treatment can prevent premature atherosclerosis and cardiovascular events in patients with FH. The aim was to evaluate the detection rate of pre-school children with FH at school doctor visits in Vienna and, moreover, to examine the frequency of FH identified in the children’s siblings by this type of screening. (2) Methods: The selective FH- screening was implemented at the school enrolment examinations in the public primary schools of Vienna. The study period included the school years starting in 2017 to 2020. FH was suspected if a questionnaire on hypercholesterolemia, or cardiovascular events in the family history or on the presence of xanthomas or xanthelasma, was positive. Subsequently, lipid testing was performed on pre-school children and their siblings and elevated lipid screening was defined as either positive by LDL-C ≥ 160 mg/dL and/or non-HDL-C ≥ 190 mg/dL or as borderline by LDL-C ≥ 130 mg/dL and/or non-HDL-C ≥ 160 mg/dL. (3) Results: 66,108 pre-school children participated in the school enrolment examination in 868 public elementary schools in Vienna. In 512 (4%) children, the questionnaire caused suspicion of FH. 344 families agreed their participation in the study. Out of 344 (52% male) tested pre-school children, 20 individuals (40% male) had elevated blood lipid levels with a mean LDL-C of 155 ± 29 mg/dL and a non-HDL-C of 180 ± 24 mg/dL. Out of 291 (44% male) tested siblings, 17 individuals (41% male) showed elevated lipids with a mean LDL-C of 144 ± 19 mg/dL, and a non-HDL-C of 174 ± 19 mg/dL. (4) Conclusions: Screening is the key for early diagnosis and treatment of FH. We have implemented a pre-school screening strategy in cooperation with school physicians. We could identify 20 pre-school children and 17 siblings with an elevated lipid screening test. Full implementation of FH-screening in the pre-school examination visits in Vienna would help to detect high-risk children.

New Therapies for Primary Hyperlipidemia

Primary hyperlipidemias include a heterogeneous set of monogenic and polygenic conditions characterized by a strong family aggregation, severe forms of hypercholesterolemia and/or hypertriglyceridemia, appearance early on life, and a high risk of cardiovascular events and/or recurrent pancreatitis. In real life, a small proportion of the primary hyperlipidemia cases is recognized and treated properly. Our goal is to present an update of current and upcoming therapies for patients with primary hyperlipidemia. Recently, new lipid-lowering medications have obtained authorization from the U.S. Food and Drug Administration and the European Medicines Agency. These drugs target metabolic pathways, including (adenosine 5'-triphosphates)-citrate lyase (bempedoic acid), proprotein convertase subtilisin/kexin 9 (inclisiran), apolipoprotein CIII (volanesorsen), and angiopoietin-like 3 (volanesorsen), that have additive effects with the actions of the currently available therapies (i.e., statins, ezetimibe or fibrates). We discuss the potential clinical indications for the novel medications. To conclude, the addition of these new medications to the therapeutic options for primary hyperlipidemia patients may increase the likelihood of achieving the treatment targets. Also, it could be a safer alternative for patients with side effects for the currently available drugs.

Vascular access for lipid apheresis: a challenge in young children with homozygous familial hypercholesterolemia

Background

Homozygous familial hypercholesterolemia (hoFH) is a rare genetic disorder leading to extremely increased LDL-cholesterol (LDL-C), resulting in high cardiovascular risk in early childhood. Lipid apheresis (LA) is an effective treatment and should be started as early as possible to prevent premature cardiovascular events. As peripheral punctures in children can be challenging due to small vessels and anxiety, this study aimed to evaluate feasibility and safety of central venous catheters (CVCs) as vascular access for LA in young children with hoFH.

Methods

Retrospective analysis (2016-2019) on four children with hoFH aged 3-5 years, performing weekly or biweekly LA with a CVC.

Results

LDL-C decreased by> 60%. In three children, the use of a permanent CVC for 698, 595, and 411 days, respectively, avoided difficult peripheral access, without the occurrence of occlusion or thrombosis. Unfortunately, one child had recurrent CVC-related infections and needed an arteriovenous fistula from the age of 5. Although the mean dwell time per catheter was 212 days, there were, as expected, severe side effects of early catheter infections with sepsis and accidental self-removal. Starting LA at an early age improved or stabilized carotid intima-media thickness (IMT) in three children. However, IMT did increase in one child caused by intolerance to peripheral punctures and LA interruption.

Conclusions

Permanent CVCs are a viable temporary access choice for LA in young children with hoFH until peripheral venipuncture is practicable. The risk of CVC-related infections needs to be taken into account.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03192-7.

Performance comparison of different classification algorithms applied to the diagnosis of familial hypercholesterolemia in paediatric subjects

Familial Hypercholesterolemia (FH) is an inherited disorder of lipid metabolism, characterized by increased low density lipoprotein cholesterol (LDLc) levels. The main purpose of the current work was to explore alternative classification methods to traditional clinical criteria for FH diagnosis, based on several biochemical and biological indicators. Logistic regression (LR), decision tree (DT), random forest (RF) and naive Bayes (NB) algorithms were developed for this purpose, and thresholds were optimized by maximization of Youden index (YI). All models presented similar accuracy (Acc), specificity (Spec) and positive predictive values (PPV). Sensitivity (Sens) and G-mean values were significantly higher in LR and RF models, compared to the DT. When compared to Simon Broome (SB) biochemical criteria for FH diagnosis, all models presented significantly higher Acc, Spec and G-mean values (p < 0.01), and lower negative predictive value (NPV, p < 0.05). Moreover, LR and RF models presented comparable Sens values. Adjustment of the cut-off point by maximizing YI significantly increased Sens values, with no significant loss in Acc. The obtained results suggest such classification algorithms can be a viable alternative to be used as a widespread screening method. An online application has been developed to assess the performance of the LR model in a wider population.

Universal Screening for Familial Hypercholesterolemia in Children in Kagawa, Japan

AIM

Familial hypercholesterolemia (FH) is an underdiagnosed autosomal dominant genetic disorder characterized by high levels of plasma low-density lipoprotein cholesterol (LDL-C) from birth. This study aimed to assess the genetic identification of FH in children with high LDL-C levels who are identified in a universal pediatric FH screening in Kagawa, Japan.

METHOD

In 2018 and 2019, 15,665 children aged 9 or 10 years underwent the universal lipid screening as part of the annual health checkups for the prevention of lifestyle-related diseases in the Kagawa prefecture. After excluding secondary hyper-LDL cholesterolemia at the local medical institutions, 67 children with LDL-C levels of ≥ 140 mg/dL underwent genetic testing to detect FH causative mutations at four designated hospitals.

RESULTS

The LDL-C levels of 140 and 180 mg/dL in 15,665 children corresponded to the 96.3 and 99.7 percentile values, respectively. Among 67 children who underwent genetic testing, 41 had FH causative mutations (36 in the LDL-receptor, 4 in proprotein convertase subtilisin/kexin type 9, and 1 in apolipoprotein B). The area under the curve of receiver operating characteristic curve predicting the presence of FH causative mutation by LDL-C level was 0.705, and FH causative mutations were found in all children with LDL-C levels of ≥ 250 mg/dL.

CONCLUSION

FH causative mutations were confirmed in almost 60% of the referred children, who were identified through the combination of the lipid universal screening as a part of the health checkup system and the exclusion of secondary hyper-LDL cholesterolemia at the local medical institutions.

Synopsis of an integrated guidance for enhancing the care of familial hypercholesterolaemia: an Australian perspective

Introduction

Familial hypercholesterolaemia (FH) is a common, heritable and preventable cause of premature coronary artery disease, with significant potential for positive impact on public health and healthcare savings. New clinical practice recommendations are presented in an abridged guidance to assist practitioners in enhancing the care of all patients with FH.

Main recommendations

Core recommendations are made on the detection, diagnosis, assessment and management of adults, children and adolescents with FH. There is a key role for general practitioners (GPs) working in collaboration with specialists with expertise in lipidology. Advice is given on genetic and cholesterol testing and risk notification of biological relatives undergoing cascade testing for FH; all healthcare professionals should develop skills in genomic medicine. Management is under-pinned by the precepts of risk stratification, adherence to healthy lifestyles, treatment of non-cholesterol risk factors, and appropriate use of low-density lipoprotein (LDL)-cholesterol lowering therapies, including statins, ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. Recommendations on service design are provided in the full guidance.

Potential impact on care of FH

These recommendations need to be utilised using judicious clinical judgement and shared decision making with patients and families. Models of care need to be adapted to both local and regional needs and resources. In Australia new government funded schemes for genetic testing and use of PCSK9 inhibitors, as well as the National Health Genomics Policy Framework, will enable adoption of these recommendations. A broad implementation science strategy is, however, required to ensure that the guidance translates into benefit for all families with FH.

Integrated Guidance for Enhancing the Care of Familial Hypercholesterolaemia in Australia

Familial hypercholesterolaemia (FH) is a dominant and highly penetrant monogenic disorder present from birth that markedly elevates plasma low-density lipoprotein (LDL)-cholesterol concentration and, if untreated, leads to premature atherosclerosis and coronary artery disease (CAD). There are approximately 100,000 people with FH in Australia. However, an overwhelming majority of those affected remain undetected and inadequately treated, consistent with FH being a leading challenge for public health genomics. To further address the unmet need, we provide an updated guidance, presented as a series of systematically collated recommendations, on the care of patients and families with FH. These recommendations have been informed by an exponential growth in published works and new evidence over the last 5 years and are compatible with a contemporary global call to action on FH. Recommendations are given on the detection, diagnosis, assessment and management of FH in adults and children. Recommendations are also made on genetic testing and risk notification of biological relatives who should undergo cascade testing for FH. Guidance on management is based on the concepts of risk re-stratification, adherence to heart healthy lifestyles, treatment of non-cholesterol risk factors, and safe and appropriate use of LDL-cholesterol lowering therapies, including statins, ezetimibe, proprotein convertase subtilisin/kexin type 9 inhibitors and lipoprotein apheresis. Broad recommendations are also provided for the organisation and development of health care services. Recommendations on best practice need to be underpinned by good clinical judgment and shared decision making with patients and families. Models of care for FH need to be adapted to local and regional health care needs and available resources. A comprehensive and realistic implementation strategy, informed by further research, including assessments of cost-benefit, will be required to ensure that this new guidance benefits all Australian families with or at risk of FH.

How registers could enhance knowledge and characterization of genetic dyslipidaemias: The experience of the LIPIGEN in Italy and of other networks for familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a common genetic disorder of lipid metabolism, still underdiagnosed and undertreated in the general population. Pathology registers could play a crucial role in the creation of a comprehensive and integrated global approach to cover all aspects of this disease. Systematic data collection of patients affected by FH has increased dramatically worldwide in the past few years. Moreover, results from registers already established for the longest time showed their potentialities in the implementation of the knowledge of FH, comparing country-specific approaches and providing real-world data about identification, management and treatment of FH individuals in the clinical practice. The potential fields of research through registers are related to the deepening of the genetic basis of disease, the study of genotype-phenotype correlation, the local adaption and implementation of diagnostic algorithms, the comparison of pharmacological approaches and treatment gaps in real-life clinical practice, the evaluation of specific subpopulations, and the identification of factors modifying cardiovascular disease risk. Registers could become also a valid resource for other rare dyslipidaemias, contributing towards the evidence-based enhancement in the worldwide care of uncommon diseases.

Identification of novel variants in the LDLR gene in Russian patients with familial hypercholesterolemia using targeted sequencing

Familial hypercholesterolemia (FH) is caused by mutations in various genes, including the LDLR, APOB and PSCK9 genes; however, the spectrum of these mutations in Russian individuals has not been fully investigated. In the present study, mutation screening was performed on the LDLR gene and other FH-associated genes in patients with definite or possible FH, using next-generation sequencing. In total, 59 unrelated patients were recruited and sorted into two separate groups depending on their age: Adult (n=31; median age, 49; age range, 23-70) and children/adolescent (n=28; median age, 11; age range, 2-21). FH-associated variants were identified in 18 adults and 25 children, demonstrating mutation detection rates of 58 and 89% for the adult and children/adolescent groups, respectively. In the adult group, 13 patients had FH-associated mutations in the LDLR gene, including two novel variants [NM_000527.4: c.433_434dupG p.(Val145Glyfs*35) and c.1186G>C p.(Gly396Arg)], 3 patients had APOB mutations and two had ABCG5/G8 mutations. In the children/adolescent group, 21 patients had FH-causing mutations in the LDLR gene, including five novel variants [NM_000527.4: c.325T>G p.(Cys109Gly), c.401G>C p.(Cys134Ser), c.616A>C p.(Ser206Arg), c.1684_1691delTGGCCCAA p.(Pro563Hisfs*14) and c.940+1_c.940+4delGTGA], and 2 patients had APOB mutations, as well as ABCG8 and LIPA mutations, being found in different patients. The present study reported seven novel LDLR variants considered to be pathogenic or likely pathogenic. Among them, four missense variants were located in the coding regions, which corresponded to functional protein domains, and two frameshifts were identified that produced truncated proteins. These variants were observed only once in different patients, whereas a splicing variant in intron 6 (c.940+1_c.940+4delGTGA) was detected in four unrelated individuals. Previously reported variants in the LDLR, APOB, ABCG5/8 and LIPA genes were observed in 33 patients. The LDLR p.(Gly592Glu) variant was detected in 6 patients, representing 10% of the FH cases reported in the present study, thus it may be a major variant present in the Russian population. In conclusion, the present study identified seven novel variants of the LDLR gene and broadens the spectrum of mutations in FH-related genes in the Russian Federation.

High-Sensitivity C-Reactive Protein and Carotid Intima Media Thickness as Markers of Subclinical Inflammation and Atherosclerosis in Pediatric Patients with Hypercholesterolemia

Hypercholesterolemia is a major cause of atherosclerosis development and premature cardiovascular disease (CVD). It leads to inflammation, which further accelerates atherosclerosis progression. Familial hypercholesterolemia (FH) is an autosomal dominant disorder characterized by elevated serum LDL-c from birth, due to a disease-causing variant in one of the causative genes (LDLR, APOB, PCSK9). In polygenic hypercholesterolemia (PH), the disease-causing genetic variant is absent; it is likely the cumulative result of multiple single nucleotide polymorphisms in LDL metabolism-related genes and other factors, such as lifestyle and environment. In high risk groups, such as patients with FH, an effective primary prevention of CVD must begin in childhood. High-sensitivity C-reactive protein (hsCRP) and carotid intima media thickness (cIMT) are two potential minimally invasive correlates of inflammation and subclinical atherosclerosis progression. hsCRP and cIMT have been shown to be significantly increased in patients with FH and PH relative to healthy controls, with some studies yielding conflicting results. In this review, we aim to summarize current knowledge and recent findings regarding the applicability of hsCRP and cIMT as markers of low-grade inflammation and subclinical atherosclerosis, focusing especially on children and adolescents with hypercholesterolemia.

Cascade screening and treatment of children with familial hypercholesterolemia in Turkey

Objectives Premature coronary artery disease is the most common preventable cause of death in developed countries, and familial hypercholesterolemia (FH) is the most common monogenetic disorder of lipid metabolism, predisposing for premature coronary artery. FH is the most common preventable cause of death in developed countries. In 2016, the national lipid screening program in school-age children has been started in Turkey. In this study, we aimed to evaluate the efficacy of lipid screening program, lipid-lowering treatments, and the challenges of treatments in children diagnosed with FH. Methods Patients diagnosed with FH in the pediatric metabolism outpatient clinic were retrospectively evaluated. Changes in lipid profile with dietary interventions and statin treatments were assessed. The results of cascade screening were analyzed. Results Fifty-one patients diagnosed with FH were enrolled in the study. Twenty-four (47.1%) were female. The mean age of the patients was 9.8 ± 3.2 years. Heterozygous LDLR gene mutation was detected in all patients. Three novel pathogenic variations were revealed with the genetic investigation. Forty-one (80.4%) patients had high adherence to CHILD-2 dietary recommendations. The mean low-density lipoprotein cholesterol (LDL-C) level decreased by 14.5 ± 7.6% after dietary intervention. Parents refused to start statin treatment in 8 (15.7%) patients. Statin treatment was initiated to 22 (43.1%) patients. Mean LDL-C level decreased from 204.1 ± 19.1 mg/dL to 137.0 ± 13.1 mg/dL. In cascade screening, 7 (13.7%) parents without a diagnosis of FH were diagnosed with FH. After the screening program, statin treatment was initiated for 18 (35.3%) parents and 7 (16.3%) siblings. Conclusions We can conclude that screening for FH in children is crucial for diagnosing FH not only in children but also in their relatives. Although statins are safe and effective in achieving the target LDL-C level, we determined significant resistance for initiating statin treatment in patients.

"Apple does not fall far from the tree" - subclinical atherosclerosis in children with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) increases the risk of atherosclerosis in children and adults. Atherosclerotic cardiovascular disease in young patients FH is usually subclinical but recognition of children with more pronounced changes is crucial for adjusting effective management. Aim of this research was to use ultrasonography with two-dimensional speckle tracking (2DST) and tonometry to evaluate atherosclerotic changes in patients with FH (parents and their offspring).

METHODS

Applanation tonometry and carotid arteries sonography with evaluation of the intima-media complex thickness (IMCT) and application of the 2DST were performed in 20 families with FH (20 parents and 29 children). The same size control group (age and sex matched) was included. Results were compared between peers and between generations together with the correlation analysis.

RESULTS

Adults with FH, in comparison with healthy peers, presented significantly more atherosclerotic plaques (9 vs. 2, p = 0.0230), had significantly thicker IMC (0.84 ± 0.19 vs. 0.56 ± 0.06 mm, p < 0.0001) and had stiffer arterial wall (for stain: 6.25 ± 2.3 vs. 8.15 ± 2.46, p = 0.0103). In children from both groups there were no atherosclerotic plaques and IMCT did not differ significantly (0.42 ± 0.07 vs. 0.39 ± 0.04, p = 0.1722). However, children with FH had significantly stiffer arterial wall according to 2DST (for strain: 9.22 ± 3.4 vs. 11.93 ± 3.11, p = 0.0057) and tonometry (for the pulse wave velocity: 4.5 ± 0.64 vs.3.96 ± 0.62, p = 0.0047). These parameters correlated with atherosclerosis surrogates in their parents (p < 0.001) but were not significantly affected by presence of presumed pathogenic gene variant.

CONCLUSIONS

Children with FH presented subclinical atherosclerosis manifested as decreased arterial wall elasticity. Degree of stiffening was associated with advancement of atherosclerosis in their parents but did not present significant association with gene variants. Sonography with application of 2DST seems to be a good candidate for comprehensive evaluation of atherosclerosis in families with FH.

Screening for Rare Genetic Variants Associated with Atherosclerosis: Opportunity for Personalized Medicine

Atherosclerosis and its clinical manifestations is a leading cause of disease burden worldwide. Currently, most of the individuals carrying a strong predisposition to complications of atherosclerosis because of monogenic dyslipidaemias remain undiagnosed and consequently are not given an opportunity for prevention. Therefore, one of the main public health challenges remains the identification of individuals with significantly increased risk for atherosclerosis due to monogenic predisposition. Next-Generation Sequencing (NGS) has revolutionized genetic testing in symptomatic patients. Although new genomic technologies are still developing, and evidence on the use of this methodology for screening purposes is still lacking, genome testing might provide a powerful tool for the identification of individuals at risk. This may pave the way for the implementation of personalized medicine in the field of atherosclerosis prevention. In this review, we discuss the potential of genetic screening for atherosclerosis prevention and present the potential target of 17 genes responsible for monogenic dyslipidaemias associated with atherosclerosis.

Widening the spectrum of genetic testing in familial hypercholesterolaemia: Will it translate into better patient and population outcomes?

Familial hypercholesterolaemia (FH) is caused by pathogenic variants in LDLR, APOB or PCSK9. Impaired low-density lipoprotein (LDL) receptor function leads to decreased LDL catabolism and premature atherosclerotic cardiovascular disease (ASCVD). Thousands of LDLR variants are known, but assignation of pathogenicity requires accurate phenotyping, family studies and assessment of LDL receptor function. Precise, genetic diagnosis of FH using targeted next generation sequencing allows for optimal treatment, distinguishing FH from pathogenically distinct disorders requiring different treatment. Polygenic hypercholesterolaemia resulting from an accumulation of LDL cholesterol-raising single nucleotide polymorphisms (SNPs) could also be suspected by this approach. Similarly, ASCVD risk could be estimated by broader sequencing of cholesterol and non-cholesterol-related genes. Both of these areas require further research. The clinical management of FH, focusing on the primary or secondary prevention of ASCVD, has been boosted by PCSK9 inhibitor therapy. The efficacy of PCSK9 inhibitors in homozygous FH may be partly predicted by the LDLR variants. While expanded genetic testing in FH is clinically useful in providing an accurate diagnosis and enabling cost-effective testing of relatives, further research is needed to establish its value in improving clinical outcomes.

Identifying Perceptions and Preferences of the General Public Concerning Universal Screening of Children for Familial Hypercholesterolaemia

BACKGROUND/AIMS

Familial hypercholesterolaemia (FH) is a common genetic disorder that, if untreated, predisposes individuals to premature coronary heart disease. As most individuals with FH remain undiagnosed, new approaches to detection are needed and should be considered a priority in public health genomics. Universal screening of children for FH has been proposed, and this study explores public perspectives on the acceptability of this approach.

METHODS

A one-day deliberative public forum was held in Perth, WA, Australia. Thirty randomly selected individuals were recruited, with self-reported sociodemographic characteristics used to obtain discursive representation. Participants were presented with information from a variety of perspectives and asked to discuss the information provided to identify points of consensus and disagreement. The data collected were analysed using thematic analysis.

RESULTS

Of the 17 participants at the forum, 16 deemed universal screening of children for FH to be acceptable. Fifteen of these 16 believed this was best performed at the time of an immunisation. Participants proposed a number of conditions that should be met to reduce the likelihood of unintended harm resulting from the screening process.

DISCUSSION/CONCLUSION

The outcomes of the forum suggest that establishing a universal screening programme for FH in childhood is acceptable to the general public in WA.

Characteristics of Children Referred to a Lipid Clinic Before and After the Universal Screening Guidelines

In 2011, universal lipid screening was recommended for children aged 9 to 11 years; the impact of this recommendation on the lipid clinic setting is unknown. We examined the rate of primary and secondary dyslipidemia diagnoses in a lipid clinic before (2010-2011) and after (2012-2015) the guideline recommendation. We conducted a retrospective study of new clinic patients aged 0 to 20 years seen between April 2010 and April 2015. Chi-square testing was applied. The 345 subjects were 58% males; 48% ≥13 years; 56% Hispanic; and 59% obese. There was no difference in the rate of dyslipidemia diagnoses between periods (before: primary 23%, secondary 73%, no dyslipidemia 4% vs after: 22%, 72%, 6%, respectively; P = .616). There was no significant difference between periods in subject demographics for the total sample, but among those with primary dyslipidemia, pre- to post-guideline percentage of subjects with public insurance decreased (71% to 39%; P = .006). Additional strategies to increase identification of children with dyslipidemia are needed.

Detecting familial hypercholesterolemia earlier in life by actively searching for affected children:The DECOPIN project

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is underdiagnosed in children. We assessed a combination of two screening methods. The first method was to detect hypercholesteraemic children and then study the parents (Ch-P pathway), and the second one was to study the offspring of FH-affected parents (P-Ch pathway).

METHODS

In the Ch-P path, primary care paediatricians were asked to include lipid profiling or, at least, total cholesterol (TC) and then lipid profiling if TC was higher than 5.2 mmol/L in any clinically indicated blood test. Children with LDL-C ≥ 3.5 mmol/L, plus either a family history of early cardiovascular disease or one parent with severe hypercholesterolemia, were referred to the lipid unit where the parents, rather than their children, were studied. In parents with definite, clinical FH, a genetic study was performed. Focused genetic testing was performed on all offspring of genetically positive parents. The P-Ch path consisted of the active study of children from definite FH adults.

RESULTS

Fifty-nine paediatricians covering a total population of 63,616 children agreed to participate in the project. Of the 216 children (122 Ch-P and 94 P-Ch) who were ultimately referred to the lipid unit, 87 children with FH (84% genetically positive) were identified. Additionally, 41 parents (from 40 families) were newly diagnosed with FH (63% genetically positive). Forty-nine different mutations were detected: 46 in the LDLR, 2 in the PCSK9 and 1 in APOB gene.

CONCLUSIONS

The implementation of active strategies to detect FH in children, in close collaboration with primary care paediatricians, provides a high-performance method for early FH detection.

Early severe coronary heart disease and ischemic heart failure in homozygous familial hypercholesterolemia: A case report

RATIONALE

Familial hypercholesterolemia (FH) is a common inherited cause of coronary heart disease (CHD) and premature death in an early age. Nevertheless, an ischemic heart failure (IHF) associated with FH seems to be rare, and an early diagnosis and therapy could influence the prognosis.

PATIENT CONCERNS

In this 13-year-old girl, multiple xanthomas began to develop from the first day of birth. Until June, 2017, she was admitted to our center due to edema, oliguria, and dyspnea during exertion, which was attributed to a recent respiratory infection.

DIAGNOSIS

Homozygous FH (HoFH), CHD, and IHF.

INTERVENTIONS

The patient has been treated with statin, ezetimibe, aspirin, and traditional heart failure (HF) medications. In addition, the beta-blocker was simultaneously administered.

OUTCOMES

Genotypes of this proband indicated homozygous mutations of low-density lipoprotein receptor (LDLR) and some co-segregated mutations, such as von Willebrand factor (VWF) and fibroblast growth factor receptors. At 6-month follow-up, we found a decreased level of plasma lipid profile, in addition to a significant improvement in 6-minute walk distance and functional class. Echocardiography indicated nonsignificant improvements in the structure and function of the heart.

LESSONS

This case report indicates that HoFH can lead to dramatically progressive endothelial damages and ventricular remodeling, severe atherosclerosis, even IHF. Genetic outcomes indicate IHF with HoFH could possibly result from LDLR mutations and some co-segregated mutations influencing endothelial function and cardiovascular remodeling. In a short-term follow-up, a combination of statins, ezetimibe, aspirin, and traditional HF agents is safe and effective for IHF with HoFH, and there is a need for further identification of drugs to ameliorate endothelial function and cardiovascular remodeling which may play an important role in long-term treatment.

Lipids in Children and Links to Adult Vascular Disease

Atherosclerosis often begins in childhood or adolescence. Post-mortem studies in children have shown the presence of coronary atheroma, and there are hereditary conditions associated with hyperlipidaemia in childhood which lead to premature cardiovascular disease. Detection of hyperlipidaemia early in life can be crucial in the prevention of premature death from atherosclerosis. The circulating lipoproteins are in a constant state of flux, with passage of apolipoproteins and lipids between the various particles. Genetic variants of apolipoproteins can cause both hypercholesterolaemia and hypertriglyceridaemia. Elevated concentrations of lipoprotein(a) predispose to coronary artery disease. Another important molecule in lipid metabolism, proprotein convertase subtilisin/kexin type 9 (PCSK9), plays a crucial role in the removal of low-density lipoprotein (LDL) receptors. Reference intervals for the various lipid subfractions are now available for children, and there are guidelines regarding when to take action regarding paediatric hyperlipidaemia. The most important genetic condition in children which may lead to premature death from coronary heart disease is familial hypercholesterolaemia (FH). FH is best diagnosed and treated early in life. Most cases are due to defects in the LDL receptor. Pharmacotherapy for FH usually involves the statin group of drugs, although newer medications are now available, especially for the treatment of homozygous FH. Statin therapy has been demonstrated to be successful in preventing cardiac events in FH. Secondary dyslipidaemia in childhood can be associated with numerous diseases including diabetes, lifestyle disorders such as obesity, and drugs. Treatment of the underlying condition usually resolves the hyperlipidaemia.

Parent-child genetic testing for familial hypercholesterolaemia in an Australian context

AIM

The aim of this study was to evaluate the clinical outcome of parent-child testing for familial hypercholesterolaemia (FH) employing genetic testing and the likely additional cost of treating each child.

METHODS

Parent-child testing for gene variants causative of FH was carried out according to Australian guidelines. The number of new cases detected, the low-density lipoprotein (LDL)-cholesterol that best predicted a mutation and the proportional reduction in LDL-cholesterol following statin treatment was evaluated. Treatment costs were calculated as the cost per mmol/L reduction in LDL-cholesterol.

RESULTS

A total of 126 adult patients, known to have a pathogenic mutation causative of FH, and their children were studied. From 244 children identified, 148 (60.7%) were genetically screened; 84 children were identified as mutative positive (M+) and 64 as mutative negative. Six of the M+ children were already on statin treatment; 40 were subsequently treated with low-dose statins, with LDL-cholesterol falling significantly by 38% (P < 0.001). The estimated cost per mmol/L reduction of LDL-cholesterol of a child receiving statins from ages 10 to 18 years is AU$1361, which can potentially be cost-effective. An LDL-cholesterol threshold of 3.5 mmol/L had a sensitivity of 92.8% and specificity of 96.6% for the detection of a mutation.

CONCLUSION

Genetic testing of children of affected parents with FH is an effective means of detecting new cases of FH. Cascade testing can enable early statin therapy with significant reductions in LDL-cholesterol concentration.

Familial Hypercholesterolemia: Cascade Screening in Children and Relatives of the Affected

OBJECTIVE

Familial Hypercholesterolemia (FH) is an inherited disorder of lipid metabolism characterized by very high low density lipoprotein (LDL) cholesterol since birth, resulting in premature atherosclerosis and coronary artery disease (CAD). Cascade screening of children and family members of proven FH individuals can identify more subjects who have high LDL cholesterol or the family mutation and appropriate intervention can reduce their risk of atherosclerosis and prevent its complications.

METHODS

Cascade screening by molecular testing, was carried out in 133 family members, comprising 24 children, of 31 probands with FH having a pathogenic mutation in LDLR/ApoB gene. Lipid profiles were obtained in 44 family members including 11 children.

RESULTS

Of 133 family members tested, 88 (66.1%) were identified to carry the family mutation. Twelve of these were children below 18 y of age and 76 were adults. CAD was present in 15 (11.2%) family members and 63(47.4%) family members, including nine children, were already on Lipid Lowering Therapy.

CONCLUSIONS

Cascade screening led to identification of 88 new cases, with a pathogenic mutation, who were at a very high risk of developing premature CAD. The authors identified 12 children with family specific mutation, out of which 9 were initiated on low dose statin therapy. Four homozygous children were treated with high dose statins because of substantially increased risk of CAD. Cascade screening, therefore, proved to be a successful initiative towards primary prevention of CAD in India.

Reverse cascade screening for familial hypercholesterolemia in high-risk Chinese families

BACKGROUND

Reverse cascade screening is not commonly employed to detect new cases of familial hypercholesterolemia (FH). We aimed to assess the outcome of this screening strategy in families in which the probands were children with severe FH.

HYPOTHESIS

Reverse cascade screening is an effective method to detect new patients with FH.

METHODS

Reverse cascade screening was undertaken starting from 47 index children with severe hypercholesterolemia; 39 were homozygous/compound heterozygous FH and 8 were heterozygous FH. Available parents, siblings, and second-degree relatives were contacted and screened.

RESULTS

From the 39 cases of homozygous/compound heterozygous FH, 80 first-degree family members were available for screening; 70 were parents and 10 were siblings. All first-degree relatives screened were genetically diagnosed with FH. None of the parents had been treated with statins at the time of diagnosis, and 10 (12.7%) had premature coronary artery disease. Additionally, 46 second-degree relatives were screened, of which 41 (89%) were diagnosed with FH. From the 8 heterozygous FH children, 17 first- and second-degree relatives were screened and 12 new cases of FH were also diagnosed. Hence, the overall diagnostic yield of screening was 2.8 new cases of FH per index case.

CONCLUSIONS

Reverse cascade screening is a highly effective method for diagnosing new cases of FH in parents, siblings, and second-degree relatives of index children with severe FH.