Cascade Screening for Familial Hypercholesterolemia and the Use of Genetic Testing

Next-Generation Sequencing in Newborn Screening: A Review of Current State

Newborn screening was first introduced at the beginning of the 1960s with the successful implementation of the first phenylketonuria screening programs. Early expansion of the included disorders was slow because each additional disorder screened required a separate test. Subsequently, the technological advancements of biochemical methodology enabled the scaling-up of newborn screening, most notably with the implementation of tandem mass spectrometry. In recent years, we have witnessed a remarkable progression of high-throughput sequencing technologies, which has resulted in a continuous decrease of both cost and time required for genetic analysis. This has enabled more widespread use of the massive multiparallel sequencing. Genomic sequencing is now frequently used in clinical applications, and its implementation in newborn screening has been intensively advocated. The expansion of newborn screening has raised many clinical, ethical, legal, psychological, sociological, and technological concerns over time. This review provides an overview of the current state of next-generation sequencing regarding newborn screening including current recommendations and potential challenges for the use of such technologies in newborn screening.

Precision Medicine Approaches to Vascular Disease: JACC Focus Seminar 2/5

In this second of a 5-part Focus Seminar series, we focus on precision medicine in the context of vascular disease. The most common vascular disease worldwide is atherosclerosis, which is the primary cause of coronary artery disease, peripheral vascular disease, and a large proportion of strokes and other disorders. Atherosclerosis is a complex genetic disease that likely involves many hundreds to thousands of single nucleotide polymorphisms, each with a relatively modest effect for causing disease. Conversely, although less prevalent, there are many vascular disorders that typically involve only a single genetic change, but these changes can often have a profound effect that is sufficient to cause disease. These are termed "Mendelian vascular diseases," which include Marfan and Loeys-Dietz syndromes. Given the very different genetic basis of atherosclerosis versus Mendelian vascular diseases, this article was divided into 2 parts to cover the most promising precision medicine approaches for these disease types.

Incorporating Cascade Effects of Genetic Testing in Economic Evaluation: A Scoping Review of Methodological Challenges

Cascade genetic testing is indicated for family members of individuals testing positive on a genetic test, and is particularly relevant for child health because of their vulnerability and the long-term health and economic implications. Cascade testing has patient- and health system-level implications; however cascade costs and health effects are not routinely considered in economic evaluation. The methodological challenges associated with incorporating cascade effects in economic evaluation require examination. The purpose of this scoping review was to identify published economic evaluations that considered cascade genetic testing. Citation databases were searched for English-language economic evaluations reporting on cascade genetic testing. Nineteen publications were included. In four, genetic testing was used to identify new index patients—cascade effects were also considered; thirteen assessed cascade genetic testing strategies for the identification of at-risk relatives; and two calculated the costs of cascade genetic testing as a secondary objective. Methodological challenges associated with incorporating cascade effects in economic evaluation are related to study design, costing, measurement and valuation of health outcomes, and modeling. As health economic studies may currently be underestimating both the cost and health benefits attributable to genetic technologies through omission of cascade effects, development of methods to address these difficulties is required.

Development of an Implementation Framework for Overcoming Underdiagnoses of Familial Hypercholesterolemia in the USA

Familial hypercholesterolemia (FH) is a genetic condition which causes elevated low-density lipoprotein cholesterol from birth. With a prevalence of 1 in 250 and the availability of effective treatments, the diagnostic rate of <1 to 10% is unacceptably low. Screening for FH is supported by multiple organizations, but it has not been broadly adopted and implemented across the USA. To investigate the implementation of FH screening, key informants were recruited from across the USA for their expertise in FH-related literature, guidelines, public health, and/or advocacy to complete -semistructured interviews guided by implementation science (RE-AIM framework). Sixteen semistructured interviews were analyzed with directed content and thematic analyses, yielding specific barriers and recommendations to improve FH screening. Barriers to FH screening included patient recruitment and participation, equitable access to healthcare, provider discomfort with screening and treating FH, provider burden, lack of public health and legislative support, FH awareness, guideline complexity, facilitation of genetic testing and cascade screening, and lack of coordination between stakeholders. Awareness, engagement, communication, and collaboration between stakeholders is integral to successful FH screening. Individualized plans will be required at national, regional, and institutional levels. FH screening implementation can be achieved through practice facilitation, streamlined screening approaches, electric medical record tools, and consensus guidelines to increase screening adoption and consistent delivery. Reliable funding and established lines of communication between stakeholders can maintain efforts as FH screening progresses.

Ten things to know about ten cardiovascular disease risk factors

Given rapid advancements in medical science, it is often challenging for the busy clinician to remain up-to-date on the fundamental and multifaceted aspects of preventive cardiology and maintain awareness of the latest guidelines applicable to cardiovascular disease (CVD) risk factors. The "American Society for Preventive Cardiology (ASPC) Top Ten CVD Risk Factors 2021 Update" is a summary document (updated yearly) regarding CVD risk factors. This "ASPC Top Ten CVD Risk Factors 2021 Update" summary document reflects the perspective of the section authors regarding ten things to know about ten sentinel CVD risk factors. It also includes quick access to sentinel references (applicable guidelines and select reviews) for each CVD risk factor section. The ten CVD risk factors include unhealthful nutrition, physical inactivity, dyslipidemia, hyperglycemia, high blood pressure, obesity, considerations of select populations (older age, race/ethnicity, and sex differences), thrombosis/smoking, kidney dysfunction and genetics/familial hypercholesterolemia. For the individual patient, other CVD risk factors may be relevant, beyond the CVD risk factors discussed here. However, it is the intent of the "ASPC Top Ten CVD Risk Factors 2021 Update" to provide a succinct overview of things to know about ten common CVD risk factors applicable to preventive cardiology.

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease.

RESULTS

Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Hypercholesterolemia and cardiovascular disease: Focus on high cardiovascular risk patients

The widespread use of statins has largely improved the treatment of hypercholesterolemia, but many patients still fail to achieve the LDL-C targets recommended by guidelines. Furthermore, some patients continue to present a very high cardiovascular (CV) risk or even an extreme risk despite being well treated, mainly due to the presence of co-morbidities such as diabetes or peripheral artery disease, which significantly increase their global CV risk. For these very high CV risk patients, the most recent European guidelines have reviewed the LDL-C goals and recommend an LDL-C reduction of at least 50% and a goal of <55 mg/dL or even <40 mg/dL. Recent clinical trials have shown that patient stratification based on the presence or absence of atherothrombotic risk factors may represent a valuable tool to identify patients at extremely high CV risk who may benefit more from an aggressive LDL-C-lowering approach. In these patients it may be appropriate to aim for the lowest LDL-C level, independently of recommended goals, with all the available pharmacological approaches.

Comparison of Universal Genetic Testing vs Guideline-Directed Targeted Testing for Patients With Hereditary Cancer Syndrome

IMPORTANCE

Hereditary factors play a key role in the risk of developing several cancers. Identification of a germline predisposition can have important implications for treatment decisions, risk-reducing interventions, cancer screening, and germline testing.

OBJECTIVE

To examine the prevalence of pathogenic germline variants (PGVs) in patients with cancer using a universal testing approach compared with targeted testing based on clinical guidelines and the uptake of cascade family variant testing (FVT).

DESIGN, SETTING, AND PARTICIPANTS

This prospective, multicenter cohort study assessed germline genetic alterations among patients with solid tumor cancer receiving care at Mayo Clinic cancer centers and a community practice between April 1, 2018, and March 31, 2020. Patients were not selected based on cancer type, disease stage, family history of cancer, ethnicity, or age.

EXPOSURES

Germline sequencing using a greater than 80-gene next-generation sequencing platform.

MAIN OUTCOMES AND MEASURES

Proportion of PGVs detected with a universal strategy compared with a guideline-directed approach and uptake of cascade FVT in families.

RESULTS

A total of 2984 patients (mean [SD] age, 61.4 [12.2] years; 1582 [53.0%] male) were studied. Pathogenic germline variants were found in 397 patients (13.3%), including 282 moderate- and high-penetrance cancer susceptibility genes. Variants of uncertain significance were found in 1415 patients (47.4%). A total of 192 patients (6.4%) had incremental clinically actionable findings that would not have been detected by phenotype or family history-based testing criteria. Of those with a high-penetrance PGV, 42 patients (28.2%) had modifications in their treatment based on the finding. Only younger age of diagnosis was associated with presence of PGV. Only 70 patients (17.6%) with PGVs had family members undergoing no-cost cascade FVT.

CONCLUSIONS AND RELEVANCE

This prospective, multicenter cohort study found that universal multigene panel testing among patients with solid tumor cancer was associated with an increased detection of heritable variants over the predicted yield of targeted testing based on guidelines. Nearly 30% of patients with high-penetrance variants had modifications in their treatment. Uptake of cascade FVT was low despite being offered at no cost.

Promise and Peril of Population Genomics for the Development of Genome-First Approaches in Mendelian Cardiovascular Disease

The rich tradition of cardiovascular genomics has placed the field in prime position to extend our knowledge toward a genome-first approach to diagnosis and therapy. Population-scale genomic data has enabled exponential improvements in our ability to adjudicate variant pathogenicity based on allele rarity, and there has been a significant effort to employ these sizeable data in the investigation of rare disease. Certainly, population genomics data has great potential to aid the development of a genome-first approach to Mendelian cardiovascular disease, but its use in the clinical and investigative decision making is limited by the characteristics of the populations studied, and the evolutionary constraints on human Mendelian variation. To truly empower clinicians and patients, the successful implementation of a genome-first approach to rare cardiovascular disease will require the nuanced incorporation of population-based discovery with detailed investigation of rare disease cohorts and prospective variant evaluation.

Polygenic Risk Score for Low-Density Lipoprotein Cholesterol Is Associated With Risk of Ischemic Heart Disease and Enriches for Individuals With Familial Hypercholesterolemia

BACKGROUND

The clinical implications of a polygenic risk score (PRS) for LDL-C (low-density lipoprotein cholesterol) are not well understood, both within the general population and individuals with familial hypercholesterolemia (FH).

METHODS

We developed the LDL-C PRS using Least Absolute Shrinkage and Selection Operator regression in 377 286 White British participants from UK Biobank and tested its association with LDL-C according to FH variant carrier status in another 41 748 whole-exome sequenced individuals. Next, we tested for an enrichment of FH variant carriers among individuals with severe hypercholesterolemia and low LDL-C PRS. Last, we contrasted the effect of the LDL-C PRS, measured LDL-C and FH variant carrier status on risk of ischemic heart disease among 3010 cases and 38 738 controls.

RESULTS

Among the 41 748 whole-exome sequenced White British individuals, 1-SD increase in the LDL-C PRS was associated with elevated LDL-C among both FH variant carriers (0.34 [95% CI, 0.22-0.47] mmol/L) and noncarriers (0.42 [95% CI, 0.42-0.43] mmol/L). Among individuals with severe hypercholesterolemia, FH variant carriers were enriched in those with a low LDL-C PRS (odds ratio, 2.20 [95% CI, 1.66-2.71] per SD). Each SD increase in the LDL-C PRS was associated with risk of ischemic heart disease to the comparable magnitude as measured LDL-C (odds ratio, 1.24 [95% CI, 1.20-1.29] and odds ratio, 1.15 [95% CI, 1.09-1.23], respectively). The LDL-C PRS was not strongly associated with other traditional ischemic heart disease risk factors.

CONCLUSIONS

An LDL-C PRS could be used to identify individuals with a higher probability of harboring FH variants. The association between ischemic heart disease and the LDL-C PRS was comparable to measured LDL-C, likely because the PRS reflects lifetime exposure to LDL-C levels.

Racial/Ethnic Disparities in Screening for and Awareness of High Cholesterol Among Pregnant Women Receiving Prenatal Care

Background Atherosclerotic cardiovascular disease remains a leading cause of morbidity and mortality among women, with younger women being disproportionately affected by traditional cardiovascular risk factors such as dyslipidemia. Despite recommendations for lipid screening in early adulthood and the risks associated with maternal dyslipidemia during pregnancy, many younger women lack access to and utilization of early screening. Accordingly, our objective was to assess the prevalence of and disparities in lipid screening and awareness of high cholesterol as an atherosclerotic cardiovascular disease risk factor among pregnant women receiving prenatal care. Methods and Results We invited 234 pregnant women receiving prenatal care at 1 of 3 clinics affiliated with the University of Pennsylvania Health System to complete our survey. A total of 200 pregnant women (86% response rate) completed the survey. Overall, 59% of pregnant women (mean age 32.2 [±5.7] years) self-reported a previous lipid screening and 79% of women were aware of high cholesterol as an atherosclerotic cardiovascular disease risk factor. Stratified by racial/ethnic subgroups, non-Hispanic Black women were less likely to report a prior screening (43% versus 67%, P=0.022) and had lower levels of awareness (66% versus 92%, P<0.001) compared with non-Hispanic White women. Non-Hispanic Black women were more likely to see an obstetrician/gynecologist for their usual source of non-pregnancy care compared with non-Hispanic White women (18% versus 5%, P=0.043). Those seeing an obstetrician/gynecologist for usual care were less likely to report a prior lipid screening compared with those seeing a primary care physician (29% versus 63%, P=0.007). Conclusions Significant racial/ethnic disparities persist in lipid screening and risk factor awareness among pregnant women. Prenatal care may represent an opportunity to enhance access to and uptake of screening among younger women and reduce variations in accessing preventive care services.

A Rare Double Heterozygous Mutation in Low-Density Lipoprotein Receptor and Apolipoprotein B-100 Genes in a Severely Affected Familial Hypercholesterolaemia Patient

Familial hypercholesterolaemia (FH) is characterized by high plasma low-density lipoprotein cholesterol (LDL-C) levels and premature cardiovascular disease risk. Mutations in the genes that encode proteins involved in LDL uptake and catabolism, including LDL-receptor (LDLR) and apolipoprotein-B (APOB), are known to cause FH. We present the case of a severely affected FH proband with two mutations in two different causing genes and characterize her first-degree blood relatives. The proband was a 54-year-old woman with a severe FH phenotype with treated LDL-C of 8.3 mmol/L, total cholesterol (TC) level of 11.6 mmol/L, peripheral artery disease, early myocardial infarction, aortic stenosis, and carotid artery disease. Exons of the LDLR and APOB genes were amplified by polymerase chain reactions (PCR). PCR products were examined by pyrosequencing and proven by bidirectional DNA sequencing. The proband was heterozygous for both the LDLR c.420G>C (p.Glu140Asp) mutation known to be pathogenic and a rare APOB c.10708C>T (p.His3570Tyr) mutation with unproven pathogenicity. Cascade testing has been performed in her 15 first-degree blood relatives. Her daughter carries only the LDLR c.420 G>C mutation with a TC of 8.4 mmol/L. Her two sisters carry only the APOB c.10708C>T with a TC of 5.7 and 6.2 mmol/L. This case provides evidence that the rare APOB c.10708C>T mutation alone is not pathogenic, but has a synergic effect on LDLR mutation. The finding is important for understanding the genotype-phenotype correlation and highlights the need to consider the presence of additional mutations in FH families where relatives have varying phenotypes.

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.

Advances, gaps and opportunities in the detection of familial hypercholesterolemia: overview of current and future screening and detection methods

PURPOSE OF REVIEW

Studies reaffirm that familial hypercholesterolemia is more prevalent than initially considered, with a population frequency of approximately one in 300. The majority of patients remains unidentified. This warrants critical evaluation of existing screening methods and exploration of novel methods of detection.

RECENT FINDINGS

New public policy recommendations on the detection of familial hypercholesterolemia have been made by a global community of experts and advocates. Phenotypic tools for diagnosing index cases remain inaccurate. Genetic testing is the gold standard for familial hypercholesterolemia and a new international position statement has been published. Correction of LDL cholesterol (LDL-C) for the cholesterol content of lipoprotein(a) [Lp(a)] may increase the precision of the phenotypic diagnosis of familial hypercholesterolemia. Cascade cotesting for familial hypercholesterolemia and elevated Lp(a) levels provides a new opportunity to stratify risk in families. Digital technology and machine learning methods, coupled with clinical alert and decision support systems, lead the way in more efficient approaches for detecting and managing index cases. Universal screening of children, combined with child-parent cascade testing, appears to be the most effective method for underpinning a population strategy for maximizing the detection of familial hypercholesterolemia.

SUMMARY

Detection of familial hypercholesterolemia can be enhanced by optimizing current diagnostic algorithms, probing electronic health records with novel information technologies and integrating universal screening of children with cascade testing of parents and other relatives.

The intersection of genomics and big data with public health: Opportunities for precision public health

Muin Khoury and co-authors discuss anticipated contributions of genomics and other forms of large-scale data in public health.

PCSK9 Variants in Familial Hypercholesterolemia: A Comprehensive Synopsis

Autosomal dominant familial hypercholesterolemia (FH) affects approximately 1/250, individuals and potentially leads to elevated blood cholesterol and a significantly increased risk of atherosclerosis. Along with improvements in detection and the increased early diagnosis and treatment, the serious burden of FH on families and society has become increasingly apparent. Since FH is strongly associated with proprotein convertase subtilisin/kexin type 9 (PCSK9), increasing numbers of studies have focused on finding effective diagnostic and therapeutic methods based on PCSK9. At present, as PCSK9 is one of the main pathogenic FH genes, its contribution to FH deserves more explorative research.

Correlates of Coronary Artery Calcification Prevalence and Severity in Patients With Heterozygous Familial Hypercholesterolemia

Background

Determinants of coronary artery calcification (CAC) prevalence and severity in heterozygous familial hypercholesterolemia (HeFH) remain understudied. The objective of this cross-sectional study was to investigate correlates of CAC in patients with HeFH.

Methods

A CAC score was calculated by a noncontrast computed tomography scan in women (n = 68) and men (n = 78) with genetically defined HeFH. We classified CAC prevalence and severity using 3 categories: CAC score = 0 Agatston Unit (AU), CAC score = 1-100 AU, and CAC score > 100 AU. Information on potential correlates of CAC including familial and personal health history, cardiovascular risk factors, lipid-lowering medication, and lifestyle habits was collected.

Results

A total of 95 patients had prevalent CAC. Independent correlates of CAC prevalence and severity included age (odds ratio [OR] per 10 years: 5.06, 95% confidence interval [CI]: 3.19, 7.93, P < 0.0001), family history of premature cardiovascular disease (OR: 3.88, 95% CI: 1.71, 8.81, P = 0.001), male sex (OR: 3.40, 95% CI: 1.49, 7.78, P = 0.004), statin use (OR: 15.5, 95% CI: 1.89, 126, P = 0.01), diet quality assessed with the Alternative Healthy Eating Index score (OR per 1 standard deviation: 0.59, 95% CI: 0.39, 0.90, P = 0.01), ever smoking (OR: 3.06, 95% CI: 1.20, 7.81, P = 0.02), receptor-negative genotype (OR: 3.17, 95% CI: 1.16, 8.66, P = 0.02), lipoprotein(a) year-score (OR per 1 standard deviation of log-transformed year-score: 1.53, 95% CI: 0.99, 2.36, P = 0.05).

Conclusions

In individuals with HeFH, age, family history of premature cardiovascular disease, sex, statin use, diet quality, smoking status, the LDLR genotype, and lipoprotein(a) concentrations were independently associated with CAC prevalence and severity.

Genetic and Clinical Characteristics of Patients With Homozygous and Compound Heterozygous Familial Hypercholesterolemia From Three Different Populations: Case Series

Homozygous familial hypercholesterolemia (HoFH) and compound heterozygous familial hypercholesterolemia (cHeFH) are rare disorders generated by disease-causing variants in both alleles of the LDLR or other familial hypercholesterolemia (FH)-related genes. HoFH and cHeFH are characterized by severely elevated low-density lipoprotein-cholesterol (LDL-C), frequently leading to early cardiovascular disease. We investigated the genetic and clinical characteristics of HoFH and cHeFH patients from the Slovenian FH registry and/or those who were previously diagnosed or managed at our institution (Slovenian, Pakhtun and Albanian ethnicity), where genetic testing is not available. Our study includes seven patients. Their median age at the time of clinical diagnosis was 6.3 years (2.9-12.9 years); 2/7 were females. Two patients were diagnosed through the universal FH screening and five patients were diagnosed due to the presence of xanthomas. All the mutations are present in LDLR gene: 7 different genotypes for HoFH (p.Cys167Leu, p.Asp178Asn, p.Cys243Tyr, p.Gly549Asp, p.Cys27Trp, p.Ile585Thr and p.Val797Met) and p.Gly549Asp/p.Gln384Pro genotype for cHeFH patient. The median initial level of LDL-C was 17.0 mmol/L [655 mg/dL] (range 7.6-21.6 mmol/L). The HoFH/cHeFH patients are clinically and genetically very diverse. The clinical criteria (as Simon Broome criteria) might be applicable already in children to raise suspicion of FH but in some cases fail to distinguish heterozygous FH and HoFH/cHeFH patients. However, genetic testing is helpful in confirming the diagnosis, also for a prompt awareness, better compliance to treatment and family screening.

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.

Women Living with Familial Hypercholesterolemia: Challenges and Considerations Surrounding Their Care

PURPOSE OF REVIEW

To highlight the gender-based differences in presentation and disparities in care for women with familial hypercholesterolemia (FH).

RECENT FINDINGS

Women with FH experience specific barriers to care including underrepresentation in research, significant underappreciation of risk, and interrupted therapy during childbearing. National and international registry and clinical trial data show significant healthcare disparities for women with FH. Women with FH are less likely to be on guideline-recommended high-intensity statin medications and those placed on statins are more likely to discontinue them within their first year. Women with FH are also less likely to be on regimens including non-statin agents such as PCSK9 inhibitors. As a result, women with FH are less likely to achieve target low-density lipoprotein cholesterol (LDL-C) targets, even those with prior atherosclerotic cardiovascular disease (ASCVD). FH is common, under-diagnosed, and under-treated. Disparities of care are more pronounced in women than men. Additionally, FH weighs differently on women throughout the course of their lives starting from choosing contraceptives as young girls along with lipid-lowering therapy, timing pregnancy, choosing breastfeeding or resumption of therapy, and finally deciding goals of care during menopause. Early identification and appropriate treatment prior to interruptions of therapy for childbearing can lead to marked reduction in morbidity and mortality. Women access care differently than men and increasing awareness among all providers, especially cardio-obstetricians, may improve diagnostic rates. Understanding the unique challenges women with FH face is crucial to close the gaps in care they experience.

Genetics, Screening, and Treatment of Familial Hypercholesterolemia: Experience Gained From the Implementation of the Vietnam Familial Hypercholesterolemia Registry

Familial hypercholesterolemia (FH) is underdiagnosed and undertreated in a majority of the low- and middle-income countries. FH registries could prove useful in bridging the knowledge gaps, supporting genetic and clinical research, and improving health-care planning and patient care. Here, we report the first usage experience of the Vietnam FH (VINAFH) Registry. The VINAFH Registry was established in 2016 as a long-term database for prospective cohorts. FH patients were detected based on the opportunistic and cascade screening. Diagnosis of FH was assessed using the Dutch Lipid Clinic Network criteria, plasma levels of low-density lipoprotein (LDL) cholesterol, and genetic testing. To date, a total of 130 patients with FH have been registered, with 48 index cases and 82 relatives. Of the 130 patients, 8 were homozygous FH patients and 38 were children. Of FH individuals, 46.7% was confirmed by genetic testing: 61 patients (96.8%) carried the LDLR mutation (c.681C > G, c.1427C > G, c.1187-?_2140 ± ?del, c.2529_2530delinsA), and two patients (3.2%) carried the PCSK9 (protein convertase subtilisin/kexin type 9) mutation (c.42_43insTG). The c.2529_2530delinsA mutation detected in this study is novel and reported only in the Vietnamese population. However, only 53.8% of FH patients were followed up post diagnosis, and only 15.3% of these were approved for lipid-lowering therapy and specialized care. Notably, factors such as knowledge about FH in patients and/or guardians of FH children and support of primary care physicians affected patient participation with respect to treatment strategies and follow-up. Genetic identification, screening, and treatment of FH were feasible in Vietnam. The VINAFH Registry significantly contributed to the formation of the government agencies legislative acts that established the importance of FH as a socially and medically important disease requiring appropriate management strategies. Other low- and middle-income countries could, thus, use the VINAFH Registry model as a reference to establish programs for FH management according to the current status.

Management of Secondary Genomic Findings

Secondary genomic findings are increasingly being returned to individuals as opportunistic screening results. A secondary finding offers the chance to identify and mitigate disease that may otherwise be unrecognized in an individual. As a form of screening, secondary findings must be considered differently from sequencing results in a diagnostic setting. For these reasons, clinicians should employ an evaluation and long-term management strategy that accounts for both the increased disease risk associated with a secondary finding and the lower positive predictive value of a screening result compared to an indication-based testing result. Here we describe an approach to the clinical evaluation and management of an individual who presents with a secondary finding. This approach enumerates five domains of evaluation-(1) medical history, (2) physical exam, (3) family history, (4) diagnostic phenotypic testing, and (5) variant correlation-through which a clinician can distinguish a molecular finding from a clinicomolecular diagnosis of genomic disease. With this framework, both geneticists and non-geneticist clinicians can optimize their ability to detect and mitigate genomic disease while avoiding the pitfalls of overdiagnosis. Our goal with this approach is to help clinicians translate secondary findings into meaningful recognition, treatment, and prevention of disease.

Identifying Familial Hypercholesterolemia Using a Blood Donor Screening Program With More Than 1 Million Volunteer Donors

Importance

Familial hypercholesterolemia is an autosomal-dominant disorder that often causes premature coronary artery disease. Unfortunately, familial hypercholesterolemia remains largely undiagnosed.

Objective

To estimate the prevalence of familial hypercholesterolemia in a population of blood donors.

Design

This analysis of deidentified data from blood donors 16 years and older who donated to Carter BloodCare, one of the largest independent blood programs in the United States, between January 2002 and December 2016. Carter BloodCare, which serves a population of about 8 million in Texas, routinely measures total nonfasting serum cholesterol levels as part of a donor health screening program. Data analysis occurred from October 2017 to March 2019.

Exposure

Blood donation.

Main Outcomes and Measures

Familial hypercholesterolemia was defined using the Make Early Diagnosis to Prevent Early Death general population criteria, with total nonfasting serum cholesterol thresholds of 270, 290, 340, and 360 mg/dL for donors younger than 20 years, 20 to 29 years, 30 to 39 years, and 40 years or older, respectively (to convert cholesterol values to mmol/L, multiply by 0.0259). For repeated donors, the maximum observed total cholesterol level was used for analyses.

Results

The study included 1 178 102 individual donors with a total of 3 038 420 blood donations. Of all individual donors (median total cholesterol level, 183 [interquartile range (IQR), 157-212] mg/dL; median age, 32 [IQR, 19-47] years; 619 583 [52.6%] women), a total of 3473 individuals (or 1 in every 339) met criteria for familial hypercholesterolemia. This group had a median (IQR) total cholesterol of 332 (297-377) mg/dL. Estimated prevalence was higher at younger ages (<30 years: 1:257) compared with older ages (≥30 years: 1:469; P < .001) and in men (1:327) compared with women (1:351; P = .03). Among 2219 repeated donors who met familial hypercholesterolemia criteria at least once, 3116 of 10 833 total donations (28.8%) met FH criteria.

Conclusions and Relevance

The prevalence of familial hypercholesterolemia using the Make Early Diagnosis to Prevent Early Death criteria in a large cohort of blood donors was similar to the estimated prevalence of this disorder in the general population. The blood donor screening program could be a novel strategy to detect and notify individuals with potential familial hypercholesterolemia, particularly younger individuals in whom early detection and treatment is especially helpful, as well as guide cascade screening.

Risk of Premature Atherosclerotic Disease in Patients With Monogenic Versus Polygenic Familial Hypercholesterolemia

BACKGROUND

A pathogenic variant in LDLR, APOB, or PCSK9 can be identified in 30% to 80% of patients with clinically-diagnosed familial hypercholesterolemia (FH). Alternatively, ∼20% of clinical FH is thought to have a polygenic cause. The cardiovascular disease (CVD) risk associated with polygenic versus monogenic FH is unclear.

OBJECTIVES

This study evaluated the effect of monogenic and polygenic causes of FH on premature (age <55 years) CVD events in patients with clinically diagnosed FH.

METHODS

Targeted sequencing of genes known to cause FH as well as common genetic variants was performed to calculate polygenic scores in patients with "possible," "probable," or "definite" FH, according to Dutch Lipid Clinic Network Criteria (n = 626). Patients with a polygenic score ≥80th percentile were considered to have polygenic FH. We examined the risk of unstable angina, myocardial infarction, coronary revascularization, or stoke.

RESULTS

A monogenic cause of FH was associated with significantly greater risk of CVD (adjusted hazard ratio: 1.96; 95% confidence interval: 1.24 to 3.12; p = 0.004), whereas the risk of CVD in patients with polygenic FH was not significantly different compared with patients in whom no genetic cause of FH was identified. However, the presence of an elevated low-density lipoprotein cholesterol (LDL-C) polygenic risk score further increased CVD risk in patients with monogenic FH (adjusted hazard ratio: 3.06; 95% confidence interval: 1.56 to 5.99; p = 0.001).

CONCLUSIONS

Patients with monogenic FH and superimposed elevated LDL-C polygenic risk scores have the greatest risk of premature CVD. Genetic testing for FH provides important prognostic information that is independent of LDL-C levels.

Familial Hypercholesterolemia and the Founder Effect Among Franco-Americans: A Brief History and Call to Action

Familial hypercholesterolemia (FH) is an inherited disorder characterized by chronically elevated low-density lipoprotein cholesterol levels and an increased risk of premature atherosclerotic cardiovascular disease. FH has been shown to disproportionately affect French Canadians and other ethnic populations due to the presence of a founder effect characterized by reduced genetic diversity resulting from relatively few individuals with FH-causing genetic mutations establishing self-contained populations. Beginning in the mid-1800s, approximately 1 million French Canadians immigrated to the Northeastern United States and largely remained in these small, tight-knit communities. Despite extensive genetic- and population-based research involving the French-Canadian founder population, primarily in the Province of Quebec, little is known regarding Franco-Americans in the United States. Concurrent with addressing the underdiagnosis rate of FH in the general population, we propose the following steps to leverage this founder effect and meet the cardiovascular needs of Franco-Americans: (1) increase cascade screening in regions of the United States with a high proportion of individuals of French-Canadian descent; (2) promote registry-based, epidemiological research to elucidate accurate prevalence estimates as well as diagnostic and treatment gaps in Franco-Americans; and (3) validate contemporary risk stratification strategies such as the Montreal-FH-SCORE to enable optimal lipid management and prevention of premature atherosclerotic cardiovascular disease among French-Canadian descendants.

Cascading After Peridiagnostic Cancer Genetic Testing: An Alternative to Population-Based Screening

PURPOSE

Despite advances in DNA sequencing technology and expanded medical guidelines, the vast majority of individuals carrying pathogenic variants of common cancer susceptibility genes have yet to be identified. An alternative to population-wide genetic screening of healthy individuals would exploit the trend for genetic testing at the time of cancer diagnosis to guide therapy and prevention, combined with augmented familial diffusion or "cascade" of genomic risk information.

METHODS

Using a multiple linear regression model, we derived the time interval to detect an estimated 3.9 million individuals in the United States with a pathogenic variant in 1 of 18 cancer susceptibility genes. We analyzed the impact of the proportion of incident patients sequenced, varying observed frequencies of pathogenic germline variants in patients with cancer, differential rates of diffusion of genetic information in families, and family size.

RESULTS

The time to detect inherited cancer predisposing variants in the population is affected by the extent of cascade to first-, second-, and third-degree relatives (FDR, SDR, TDR, respectively), family size, prevalence of mutations in patients with cancer, and the proportion of patients with cancer sequenced. In a representative scenario, assuming a 7% prevalence of pathogenic variants across cancer types, an average family size of 3 per generation, and 15% of incident patients with cancer in the United States undergoing germline testing, the time to detect all 3.9 million individuals with pathogenic variants in 18 cancer susceptibility genes would be 46.2, 22.3, 13.6, and 9.9 years if 10%, 25%, 50%, and 70%, respectively, of all FDR, SDR, and TDR were tested for familial mutations.

CONCLUSION

Peridiagnostic and cascade cancer genetic testing offers an alternative strategy to achieve population-wide identification of cancer susceptibility mutations.

Genetic testing for hereditary cancer syndromes: patient recommendations for improved risk communication

Background

Multi‐gene panel testing is replacing single‐gene testing for patients with suspected hereditary cancer syndromes. The detection of a hereditary cancer syndrome allows tested individuals to initiate enhanced primary and secondary prevention efforts—where available—with a view to reduce disease burden. Current policy prevents testing programmes from communicating genetic test results with potentially affected family members, yet it is well documented that tested individuals face multiple challenges in initiating such discussions with relatives.

Objective

In response to this challenge, we sought patient recommendations about how to improve genetic risk communication to enhance interfamilial discussions about primary and secondary disease prevention.

Design

We conducted 25 semi‐structured interviews with individuals who received genetic testing through British Columbia’s Hereditary Cancer Program between 2017 and 2018. Interviews were professionally transcribed and analysed using a constant comparative approach.

Results

Participants described difficulty engaging in conversations with relatives who were resistant to receiving genetic risk information, when communicating with younger relatives and where participants reported strained familial relationships. Participants recommended that testing facilities provide a summary of results and implications and that resources be made available to prepare patients for challenging discussions with family members.

Discussion

Our study demonstrates that individuals undergoing genetic testing for suspected hereditary cancer syndromes would benefit from additional supportive resources alongside genetic counselling. Providing this on‐going support will enhance the accurate and transparent communication of risk to facilitate the uptake of cascade testing and enhanced prevention strategies.

A Global Review on the Utility of Genetic Testing for Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a genetic disorder of cholesterol metabolism that affects an estimated 1/250 persons in the United States and abroad. FH is hallmarked by high low-density lipoprotein (LDL) cholesterol and an increased risk of premature atherosclerotic cardiovascular disease. This review summarizes recent global evidence showing the utility of FH genetic testing across diverse populations. Clinical and other qualitative outcomes following FH genetic testing were improved FH diagnosis, treatment initiation or continued treatment, treatment modification, improved total or LDL cholesterol levels, education on lifestyle management, and genetic counseling. This summary of evidence should be considered by those seeking overall evidence and knowledge gaps on the utility of FH genetic testing from a global perspective and for certain ethnic and age populations. These findings can be used to inform insurance policies and coverage decisions for FH genetic testing, policy recommendations to reduce the clinical and public health burden of FH, clinical practice and guidelines to improve the management of FH populations, and ongoing research involving FH genetic testing. We conclude that further investigations are needed to examine: (1) non-clinical outcomes following FH genetic testing; (2) patient-reported outcomes following FH genetic testing to convey patient experiences, values, and goals; and (3) clinical outcomes following FH genetic testing in non-Caucasian and pediatric populations in the United States and abroad.

Association of Rare Pathogenic DNA Variants for Familial Hypercholesterolemia, Hereditary Breast and Ovarian Cancer Syndrome, and Lynch Syndrome With Disease Risk in Adults According to Family History

IMPORTANCE

Pathogenic DNA variants associated with familial hypercholesterolemia, hereditary breast and ovarian cancer syndrome, and Lynch syndrome are widely recognized as clinically important and actionable when identified, leading some clinicians to recommend population-wide genomic screening.

OBJECTIVES

To assess the prevalence and clinical importance of pathogenic or likely pathogenic variants associated with each of 3 genomic conditions (familial hypercholesterolemia, hereditary breast and ovarian cancer syndrome, and Lynch syndrome) within the context of contemporary clinical care.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used gene-sequencing data from 49 738 participants in the UK Biobank who were recruited from 22 sites across the UK between March 21, 2006, and October 1, 2010. Inpatient hospital data date back to 1977; cancer registry data, to 1957; and death registry data, to 2006. Statistical analysis was performed from July 22, 2019, to November 15, 2019.

EXPOSURES

Pathogenic or likely pathogenic DNA variants classified by a clinical laboratory geneticist.

MAIN OUTCOMES AND MEASURES

Composite end point specific to each genomic condition based on atherosclerotic cardiovascular disease events for familial hypercholesterolemia, breast or ovarian cancer for hereditary breast and ovarian cancer syndrome, and colorectal or uterine cancer for Lynch syndrome.

RESULTS

Among 49 738 participants (mean [SD] age, 57 [8] years; 27 144 female [55%]), 441 (0.9%) harbored a pathogenic or likely pathogenic variant associated with any of 3 genomic conditions, including 131 (0.3%) for familial hypercholesterolemia, 235 (0.5%) for hereditary breast and ovarian cancer syndrome, and 76 (0.2%) for Lynch syndrome. Presence of these variants was associated with increased risk of disease: for familial hypercholesterolemia, 28 of 131 carriers (21.4%) vs 4663 of 49 607 noncarriers (9.4%) developed atherosclerotic cardiovascular disease; for hereditary breast and ovarian cancer syndrome, 32 of 116 female carriers (27.6%) vs 2080 of 27 028 female noncarriers (7.7%) developed associated cancers; and for Lynch syndrome, 17 of 76 carriers (22.4%) vs 929 of 49 662 noncarriers (1.9%) developed colorectal or uterine cancer. The predicted probability of disease at age 75 years despite contemporary clinical care was 45.3% for carriers of familial hypercholesterolemia, 41.1% for hereditary breast and ovarian cancer syndrome, and 38.3% for Lynch syndrome. Across the 3 conditions, 39.7% (175 of 441) of the carriers reported a family history of disease vs 23.2% (34 517 of 148 772) of noncarriers.

CONCLUSIONS AND RELEVANCE

The findings suggest that approximately 1% of the middle-aged adult population in the UK Biobank harbored a pathogenic variant associated with any of 3 genomic conditions. These variants were associated with an increased risk of disease despite contemporary clinical care and were not reliably detected by family history.

Association of Monogenic vs Polygenic Hypercholesterolemia With Risk of Atherosclerotic Cardiovascular Disease

Importance

Monogenic familial hypercholesterolemia (FH) is associated with lifelong elevations in low-density lipoprotein cholesterol (LDL-C) levels and increased risk of atherosclerotic cardiovascular disease (CVD). However, many individuals with hypercholesterolemia have a polygenic rather than a monogenic cause for their condition. It is unclear if a genetic variant for hypercholesterolemia alters the risk of CVD.

Objectives

To assess whether a genetic variant for hypercholesterolemia alters the risk of atherosclerotic CVD and to evaluate how this risk compares with that of nongenetic hypercholesterolemia.

Design, Setting, and Participants

In this genetic-association, case-control, cohort study, individuals aged 40 to 69 years were recruited by the UK Biobank from across the United Kingdom between March 13, 2006, and October 1, 2010, and followed up until March 31, 2017. Genotyping array and exome sequencing data from the UK Biobank cohort were used to identify individuals with monogenic (LDLR, APOB, and PCSK9) or polygenic hypercholesterolemia (LDL-C polygenic score >95th percentile based on 223 single-nucleotide variants in the entire cohort). The data were analyzed from July 1, 2019, to December 30, 2019.

Main Outcomes and Measures

The study investigated the association of genotype with the risk of coronary and carotid revascularization, myocardial infarction, ischemic stroke, and all-cause mortality among the overall study population and among participants with monogenic FH (n = 277), polygenic hypercholesterolemia (n = 2379), or hypercholesterolemia with undetermined cause (n = 2232) at comparable levels of LDL-C measured at study enrollment.

Results

For the 48 741 individuals with genotyping array and exome sequencing data, the mean (SD) age was 56.6 (8.0) years, and 54.5% were female (n = 26 541 of 48 741). A monogenic FH variant for hypercholesterolemia was found in 277 individuals (0.57%, 1 in 176 individuals). Participants with monogenic FH were significantly more likely than those without monogenic FH to experience an atherosclerotic CVD event at 55 years or younger (17 of 277 [6.1%] vs 988 of 48 464 [2.0%]; P < .001). Compared with the general population, both monogenic and polygenic hypercholesterolemia were associated with an increased risk of CVD events. Moreover, among individuals with comparable levels of LDL-C, both monogenic (hazard ratio, 1.93; 95% CI, 1.34-2.77; P < .001) and polygenic hypercholesterolemia (hazard ratio, 1.26; 95% CI, 1.03-1.55; P = .03) were significantly associated with an increased risk of CVD events compared with the risk of such events in individuals with hypercholesterolemia without an identified genetic cause.

Conclusions and Relevance

The findings of this study suggest that among individuals with hypercholesterolemia, genetic determinants of LDL-C levels may impose additional risk of CVD. Thus, understanding the possible genetic cause of hypercholesterolemia may provide important prognostic information to treat patients.

Cascade Genetic Testing of Relatives for Hereditary Cancer Risk: Results of an Online Initiative

In cascade testing, genetic testing for an identified familial pathogenic variant extends to disease-free relatives to allow genetically targeted disease prevention. We evaluated the results of an online initiative in which carriers of 1 of 30 cancer-associated genes, or their first-degree relatives, could offer low-cost testing to at-risk first-degree relatives. In the first year, 1101 applicants invited 2280 first-degree relatives to undergo genetic testing. Of invited relatives, 47.5% (95% confidence interval [CI] = 45.5 to 49.6%) underwent genetic testing, and 12.0% (95% CI = 9.2 to 14.8%) who tested positive continued the cascade by inviting additional relatives to test. Of tested relatives, 4.9% (95% CI = 3.8 to 6.1%) had a pathogenic variant in a different gene from the known familial one, and 16.8% (95% CI = 14.7 to 18.8%) had a variant of uncertain significance. These results suggest that an online, low-cost program is an effective approach to implementing cascade testing, and that up to 5% of the general population may carry a pathogenic variant in 1 of 30 cancer-associated genes.

Ten things to know about ten cardiovascular disease risk factors ("ASPC Top Ten - 2020")

Preventive cardiology involves understanding and managing multiple cardiovascular disease (CVD) risk factors. Given the rapid advancements in medical science, it may be challenging for the busy clinician to remain up-to-date on the multifaceted and fundamental aspects of CVD prevention, and maintain awareness of the newest applicable guidelines. The "American Society for Preventive Cardiology (ASPC) Top Ten 2020" summarizes ten essential things to know about ten important CVD risk factors, listed in tabular formats. The ten CVD risk factors include unhealthful nutrition, physical inactivity, dyslipidemia, hyperglycemia, high blood pressure, obesity, considerations of select populations (older age, race/ethnicity, and gender), thrombosis/smoking, kidney dysfunction and genetics/familial hypercholesterolemia. For the individual patient, other CVD risk factors may be relevant, beyond the CVD risk factors discussed here. However, it is the intent of the "ASPC Top Ten 2020" to provide a succinct overview of things to know about ten common CVD risk factors applicable to preventive cardiology.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

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.

The number needed to benefit: estimating the value of predictive analytics in healthcare

Predictive analytics in health care has generated increasing enthusiasm recently, as reflected in a rapidly growing body of predictive models reported in literature and in real-time embedded models using electronic health record data. However, estimating the benefit of applying any single model to a specific clinical problem remains challenging today. Developing a shared framework for estimating model value is therefore critical to facilitate the effective, safe, and sustainable use of predictive tools into the future. We highlight key concepts within the prediction-action dyad that together are expected to impact model benefit. These include factors relevant to model prediction (including the number needed to screen) as well as those relevant to the subsequent action (number needed to treat). In the simplest terms, a number needed to benefit contextualizes the numbers needed to screen and treat, offering an opportunity to estimate the value of a clinical predictive model in action.

New Case Detection by Cascade Testing in Familial Hypercholesterolemia: A Systematic Review of the Literature

BACKGROUND

The prevalence of familial hypercholesterolemia is 1 in 250, but <10% of patients are diagnosed. Cascade testing enables early detection of cases through systematic family tracing. Establishment of familial hypercholesterolemia cascade testing programs in the US could be informed by approaches used elsewhere.

METHODS

We conducted a systematic review of published studies in the English language of cascade testing for familial hypercholesterolemia, which reported the number of index cases and number of relatives tested and specified methods of contacting relatives and testing modalities methods utilized. For each study, we calculated yield (proportion of relatives who test positive) and new cases per index case, to facilitate comparison.

RESULTS

We identified 10 studies from the literature that met inclusion criteria; the mean number of probands and relatives per study was 242 and 826, respectively. The average yield was 44.76% with a range of 30% to 60.5%, and the mean new cases per index case was 1.65 with a range of 0.22 to 8.0. New cases per index case tended to be greater in studies that used direct contact versus indirect contact (2.06 versus 0.86), tested beyond first-degree relatives versus only first-degree relatives (3.65 versus 0.80), used active sample collection versus collection at clinic (4.11 versus 1.06), and utilized genetic testing versus biochemical testing (2.47 versus 0.42).

CONCLUSIONS

New case detection in familial hypercholesterolemia cascade testing programs tended to be higher with direct contact of relatives, testing beyond first-degree relatives, in-home-based sample collection, and genetic testing. These findings should be helpful for establishing cascade testing programs in the United States.

Tracking human genes along the translational continuum

Understanding the drivers of research on human genes is a critical component to success of translation efforts of genomics into medicine and public health. Using publicly available curated online databases we sought to identify specific genes that are featured in translational genetic research in comparison to all genomics research publications. Articles in the CDC’s Public Health Genomics and Precision Health Knowledge Base were stratified into studies that have moved beyond basic research to population and clinical epidemiologic studies (T1: clinical and population human genome epidemiology research), and studies that evaluate, implement, and assess impact of genes in clinical and public health areas (T2+: beyond bench to bedside). We examined gene counts and numbers of publications within these phases of translation in comparison to all genes from Medline. We are able to highlight those genes that are moving from basic research to clinical and public health translational research, namely in cancer and a few genetic diseases with high penetrance and clinical actionability. Identifying human genes of translational value is an important step towards determining an evidence-based trajectory of the human genome in clinical and public health practice over time.

Precision screening for familial hypercholesterolaemia: a machine learning study applied to electronic health encounter data

BACKGROUND

Cardiovascular outcomes for people with familial hypercholesterolaemia can be improved with diagnosis and medical management. However, 90% of individuals with familial hypercholesterolaemia remain undiagnosed in the USA. We aimed to accelerate early diagnosis and timely intervention for more than 1·3 million undiagnosed individuals with familial hypercholesterolaemia at high risk for early heart attacks and strokes by applying machine learning to large health-care encounter datasets.

METHODS

We trained the FIND FH machine learning model using deidentified health-care encounter data, including procedure and diagnostic codes, prescriptions, and laboratory findings, from 939 clinically diagnosed individuals with familial hypercholesterolaemia (395 of whom had a molecular diagnosis) and 83 136 individuals presumed free of familial hypercholesterolaemia, sampled from four US institutions. The model was then applied to a national health-care encounter database (170 million individuals) and an integrated health-care delivery system dataset (174 000 individuals). Individuals used in model training and those evaluated by the model were required to have at least one cardiovascular disease risk factor (eg, hypertension, hypercholesterolaemia, or hyperlipidemia). A Health Insurance Portability and Accountability Act of 1996-compliant programme was developed to allow providers to receive identification of individuals likely to have familial hypercholesterolaemia in their practice.

FINDINGS

Using a model with a measured precision (positive predictive value) of 0·85, recall (sensitivity) of 0·45, area under the precision-recall curve of 0·55, and area under the receiver operating characteristic curve of 0·89, we flagged 1 331 759 of 170 416 201 patients in the national database and 866 of 173 733 individuals in the health-care delivery system dataset as likely to have familial hypercholesterolaemia. Familial hypercholesterolaemia experts reviewed a sample of flagged individuals (45 from the national database and 103 from the health-care delivery system dataset) and applied clinical familial hypercholesterolaemia diagnostic criteria. Of those reviewed, 87% (95% Cl 73-100) in the national database and 77% (68-86) in the health-care delivery system dataset were categorised as having a high enough clinical suspicion of familial hypercholesterolaemia to warrant guideline-based clinical evaluation and treatment.

INTERPRETATION

The FIND FH model successfully scans large, diverse, and disparate health-care encounter databases to identify individuals with familial hypercholesterolaemia.

FUNDING

The FH Foundation funded this study. Support was received from Amgen, Sanofi, and Regeneron.

Healthcare Utilization and Patients' Perspectives After Receiving a Positive Genetic Test for Familial Hypercholesterolemia

BACKGROUND

The MyCode Community Health Initiative (MyCode) is returning actionable results from whole exome sequencing. Familial hypercholesterolemia (FH) is an inherited condition characterized by premature cardiovascular disease.

METHODS

We used multiple methods to assess care in 28 MyCode participants who received FH results. Chart reviews were conducted on 23 individuals in the sample and 7 individuals participated semistructured interviews.

RESULTS

Chart reviews for 23 individuals with a Geisinger primary care provider found that 4 individuals (17% of 23) were at LDL-C (low-density lipoprotein cholesterol) goal (of either LDL-C <100 mg/dL for primary prevention and LDL-C <70 mg/dL for secondary prevention) and 17 individuals (74% of 23) were prescribed lipid-lowering therapy before genetic result disclosure. After disclosure of the genetic test result, 5 individuals (22% of 23) met their LDL-C goal and 18 individuals (78% of 23) were prescribed lipid-lowering therapy. Follow-up care about this result was not documented for 4 individuals (17% of 23). Changes to intensity of medication management were made for 8 individuals (47% of 17 individuals previously prescribed lipid-lowering therapy). Interviewed individuals (n=7) were not surprised by their result as all knew they had high cholesterol; however, individuals did not seem to discern FH as a separate condition from their high cholesterol.

CONCLUSIONS

Among individuals receiving genetic diagnosis of FH, >25% had no changes to lipid-lowering therapy, despite not being at LDL-C goal and learning their high cholesterol is related to a genetic condition requiring more aggressive treatment. Individuals and clinicians may have an inadequate understanding of FH as a distinct condition requiring enhanced medical management.

Canadian Cardiovascular Society Position Statement on Familial Hypercholesterolemia: Update 2018

Familial hypercholesterolemia (FH) is the most common monogenic disorder causing premature atherosclerotic cardiovascular disease. It affects 1 in 250 individuals worldwide, and of the approximately 145,000 Canadians estimated to have FH, most are undiagnosed. Herein, we provide an update of the 2014 Canadian Cardiovascular Society position statement on FH addressing the need for case identification, prompt recognition, and treatment with statins and ezetimibe, and cascade family screening. We provide a new Canadian definition for FH and tools for clinicians to make a diagnosis. The risk of atherosclerotic cardiovascular disease in patients with "definite" FH is 10- to 20-fold that of a normolipidemic individual and initiating treatment in youth or young adulthood can normalize life expectancy. Target levels for low-density lipoprotein cholesterol are proposed and are aligned with the Canadian Cardiovascular Society guidelines on dyslipidemia. Recommendation for the use of inhibitors of proprotein convertase kexin/subtilisin type 9 are made in patients who cannot achieve therapeutic low-density lipoprotein cholesterol targets on maximally tolerated statins and ezetimibe. The writing committee used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology in the preparation of the present document, which offers guidance for practical evaluation and management of patients with FH. This position statement also aims to raise awareness of FH nationally, and to mobilize patient support, promote knowledge translation, and availability of treatment and health care resources for this under-recognized, but important medical condition.

Beyond Public Health Genomics: Can Big Data and Predictive Analytics Deliver Precision Public Health?

The field of public health genomics has matured in the past two decades and is beginning to deliver genomic-based interventions for health and health care. In the past few years, the terms precision medicine and precision public health have been used to include information from multiple fields measuring biomarkers as well as environmental and other variables to provide tailored interventions. In the context of public health, "precision" implies delivering the right intervention to the right population at the right time, with the goal of improving health for all. In addition to genomics, precision public health can be driven by "big data" as identified by volume, variety, and variability in biomedical, sociodemographic, environmental, geographic, and other information. Most current big data applications in health are in elucidating pathobiology and tailored drug discovery. We explore how big data and predictive analytics can contribute to precision public health by improving public health surveillance and assessment, and efforts to promote uptake of evidence-based interventions, by including more extensive information related to place, person, and time. We use selected examples drawn from child health, cardiovascular disease, and cancer to illustrate the promises of precision public health, as well as current methodologic and analytic challenges to big data to fulfill these promises.

Clinical Practice Recommendations for Pediatric Dyslipidemia

The leading cause of mortality in the United States is atherosclerotic cardiovascular disease (ASCVD). Atherosclerotic lesions begin during childhood and can place individuals at greater risk for ASCVD. Providers play an active role in preventing the progression of risk factors and future ASCVD events through appropriate clinical management of genetic and acquired dyslipidemias in the pediatric population. Health care providers need to be aware of current recommendations related to screening for dyslipidemia, lifestyle modification strategies, pharmacologic treatment, and guidelines for ongoing monitoring. Most patients with mild to moderate dyslipidemia can be managed by a primary care provider. It is imperative that providers understand the pathophysiology, screening methods, and available treatment options to effectively manage the condition. Frequent reassessment of family history and adherence to lifestyle modifications and pharmacologic interventions is essential for effective treatment.

Barriers and Facilitators to Genetic Testing for Familial Hypercholesterolemia in the United States: A Review

Familial Hypercholesterolemia (FH) is an underdiagnosed condition in the United States (US) and globally, affecting an estimated 1/250 individuals. It is a genetic risk factor for premature cardiovascular disease and is responsible for an estimated 600,000 to 1.2 million preventable vascular events. Studies show that FH genetic testing can identify a causal gene variant in 60 to 80% of clinically suspected FH cases. However, FH genetic testing is currently underutilized in clinical settings in the US despite clinical recommendations and evidence supporting its use. Reasons for underutilization are not well understood. We conducted a literature review in the PubMed/MEDLINE database and eight peer-reviewed journals. After filtering for and reviewing 2340 articles against our inclusion criteria, we included nine commentaries or expert opinions and eight empirical studies reported between January 2014 and March 2019 in our review. After applying the Consolidated Framework for Implementation Research (CFIR), we identified a total of 26 potential barriers and 15 potential facilitators (estimated barrier to facilitator ratio of 1.73). We further estimated ratios of potential barriers to facilitators for each CFIR domain (Characteristics of Intervention, Outer Setting, Inner Setting, Characteristics of Individuals, and Process). Findings derived from our systematic approach to the literature and calculations of estimated baseline ratios of barriers and facilitators can guide future research to understand FH genetic testing implementation in diverse clinical settings. Our systematic approach to the CFIR could also be used as a model to understand or compare barriers and facilitators to other evidence-based genetic testing processes in health care settings in the US and abroad.

Prediction of Familial Hypercholesterolemia in Patients at High Atherosclerotic Cardiovascular Disease Risk Using a Recently Validated Algorithm

Background

The prevalence of heterozygous familial hypercholesterolemia (FH) is 1 of 250 in the general population and approximately 1 of 125 in patients with atherosclerotic cardiovascular disease (ASCVD), yet only a minority are diagnosed. The diagnostic criteria for FH rely on a point system using low-density lipoprotein cholesterol (LDL-C), family history, cutaneous manifestations, and molecular diagnosis. The aim of the present study was to determine the prevalence of FH in the Relating Evidence to Achieve Cholesterol Targets (REACT) registry.

Methods

Patients were enrolled as ASCVD (n = 86) or FH (n = 109) and with an LDL-C level > 3.0 mmol/L despite maximally tolerated statin therapy. FH was diagnosed clinically using a validated clinical application integrating an imputation for baseline (untreated) LDL-C levels.

Results

There were 109 men and 86 women with a mean age of 63 ± 12 years. Diabetes (29.7%), hypertension (62.1%), smoking (37.9%), and family history of premature ASCVD (59.5%) were common. On-treatment LDL-C was 4.26 ± 0.94 mmol/L. On the basis of the dose and type of statin ± ezetimibe, imputed baseline LDL-C was 7.04 ± 2.90 mmol/L. A diagnosis of probable/definite FH was found in 54.7%, 49.5%, and 61.5% of patients according to the Simon Broome, Dutch Lipid Clinic Network criteria, and the new Canadian FH definition, respectively. Of note, 40% of patients in the ASCVD inclusion subgroup had probable or definite FH.

Conclusions

Our study reveals that a substantial proportion of patients with ASCVD whose LDL-C levels are > 3.0 mmol/L despite maximally tolerated statins have heterozygous FH. Clinicians should consider using the recently described algorithm to assess the possibility of FH in this high-risk population.

Finding missed cases of familial hypercholesterolemia in health systems using machine learning

Familial hypercholesterolemia (FH) is an underdiagnosed dominant genetic condition affecting approximately 0.4% of the population and has up to a 20-fold increased risk of coronary artery disease if untreated. Simple screening strategies have false positive rates greater than 95%. As part of the FH Foundation's FIND FH initiative, we developed a classifier to identify potential FH patients using electronic health record (EHR) data at Stanford Health Care. We trained a random forest classifier using data from known patients (n = 197) and matched non-cases (n = 6590). Our classifier obtained a positive predictive value (PPV) of 0.88 and sensitivity of 0.75 on a held-out test-set. We evaluated the accuracy of the classifier's predictions by chart review of 100 patients at risk of FH not included in the original dataset. The classifier correctly flagged 84% of patients at the highest probability threshold, with decreasing performance as the threshold lowers. In external validation on 466 FH patients (236 with genetically proven FH) and 5000 matched non-cases from the Geisinger Healthcare System our FH classifier achieved a PPV of 0.85. Our EHR-derived FH classifier is effective in finding candidate patients for further FH screening. Such machine learning guided strategies can lead to effective identification of the highest risk patients for enhanced management strategies.