Current status of familial hypercholesterolemia in Chinese populations

Metabolomic Approach to Screening Homozygotes in Chinese Patients with Severe Familial Hypercholesterolemia

Homozygous familial hypercholesterolemia (HoFH) is a rare inborn-errors-of-metabolism disorder characterized by devastatingly elevated low-density lipoprotein cholesterol (LDL-C) and premature cardiovascular disease. The gold standard for screening and diagnosing HoFH is genetic testing. In China, it is expensive and is always recommended for the most likely HoFH subjects with aggressive LDL-C phenotype. However, the LDL-C levels of HoFH patients and a substantial proportion of heterozygous FH (HeFH) patients overlapped considerably. Here, we performed a cost-effective metabolomic profiling on genetically diagnosed HoFH (n = 69) and HeFH patients (n = 101) with overlapping LDL-C levels, aiming to discovery a unique metabolic pattern for screening homozygotes in patients with severe FH. We demonstrated a differential serum metabolome profile in HoFH patients compared to HeFH patients. Twenty-one metabolomic alterations showed independent capability in differentiating HoFH from severe HeFH. The combined model based on seven identified metabolites yielded a corrected diagnosis in 91.3% of HoFH cases with an area under the curve value of 0.939. Collectively, this study demonstrated that metabolomic profiling serves as a useful and economical approach to preselecting homozygotes in FH patients with severe hypercholesterolemia and may help clinicians to conduct selective genetic confirmation testing and familial cascade screening.

Correlation of cardiovascular risk predictors with overweight and obesity in patients with familial hypercholesterolemia

Purpose

We aimed to analyze the correlation between overweight and obesity-related indicators and cardiovascular risk predictors in patients with familial hypercholesterolemia (FH) and to evaluate their mutual predictive properties.

Methods

A total of 103 patients with FH included from 2004 to 2017 were retrospectively analyzed. Pearson correlation analysis and multiple linear regression analysis were used to assess the correlation between overweight and obesity-related indicators and cardiovascular risk predictors in FH patients. Subject operating characteristic (ROC) curve was used to analyze their reciprocal predictive performance.

Results

(1) Atherogenic index of plasma (AIP) (β = 0.020) and ApoB/ApoA1 Ratio (BAR) (β = 0.015) were independently correlated with body mass index (BMI) (P < 0.05); AIP (β = 1.176) was independently correlated with waist-to-hip ratio (WHR) (P < 0.01); AIP (β = 1.575), BAR (β = 0.661) and atherogenic coefficient (AC) (β = 0.427) were independently correlated with waist-to-height ratio (WHtR) (P < 0.05). (2) The area under the ROC (AUC) for overweight corresponding to AIP, BAR, and AC were 0.695 (95% CI = 0.593–0.797, P < 0.01), 0.660 (95% CI = 0.555–0.766, P < 0.01), and 0.632 (95% CI = 0.525–0.740, P < 0.05), respectively; and AUCs for central obesity corresponding to AIP, BAR and AC were 0.757 (95% CI = 0.656–0.857, P < 0.001), 0.654 (95% CI = 0.536–0.771, P < 0.05) and 0.651 (95% CI = 0.538–0.764, P < 0.05), respectively. The AUCs for moderate risk of AIP corresponding to BMI, WHR, and WHtR were 0.709 (95% CI = 0.608–0.811, P < 0.001), 0.773 (95% CI = 0.678–0.867, P < 0.001), 0.739 (95% CI = 0.641–0.836, P < 0.001), respectively, and BMI, WHR and WHtR corresponded to an AUC of 0.691 (95% CI = 0.585–0.797, P < 0.01), 0.734 (95% CI = 0.632–0.835, P < 0.001), and 0.706 (95% CI = 0.603–0.810, P < 0.01) for high risk of AIP, respectively.

Conclusion

AIP has independent positive linear correlation with indicators related to overweight and obesity in FH patients; AIP has good predictive performance for overweight and obesity in FH patients, and WHR has good performance for identifying moderate and high risk of AIP in FH patients.

Expanding the genetic spectrum for Chinese familial hypercholesterolemia population with six genetic mutations identified using a next-generation sequencing-based laboratory-developed screening test

BACKGROUND

This study was to reveal the prevalence of definite familial hypercholesterolemia (FH) in the hospital-visiting population, determine the pathogenic mutation detection rate in clinically diagnosed definite FH patients, and expand the FH mutation spectrum in China.

METHODS

Blood lipid profiles of 41,803 patients visiting the hospital were investigated and 4967 patients with clinical diagnoses of other metabolic diseases were excluded. One hundred and seventy-three (0.41%) received a definite diagnosis of FH according to the Dutch Lipid Clinical Network Criteria-Chinese Revised Version (DLCN-CRV), and 18 patients subsequently agreed to undergo genetic testing. A next-generation sequencing (NGS)-based laboratory-developed test covering the exonic regions of 24 lipid metabolism-related genes was conducted alongside in silico analyses to identify possible FH mutations in 16 definite FH patients, according to the American College of Medical Genetics and Genomics (ACMG) criteria. Sanger sequencing was used to confirm mutations, and SWISS-MODEL was used to simulate the molecular structures of the confirmed protein-carrying mutations.

RESULTS

The FH prevalence was 0.41% for the 41,803 individuals (DLCN-CRV grade >8) and 25% of definite FH patients carried six FH pathogenic mutations (≥ACMG Class 4). All genetic variants were confirmed by Sanger sequencing. Five pathogenic variants on the LDLR gene (NM_000527: c.C1783T: p.R595W, c.T493G: p.W165G, c.G1879A: p.A627T, c.G682T: p.E228X, and exon10: c.G1432A: p.G478R) and one pathogenic variant on APOB (NM_000384: c.C10579T: p.R3527W) in 25% of the identified definite FH patients. Two pathogenic mutations, c.T493G (p.W165G) and c.C1783T (p.R595W), were added to the current genetic spectrum of FH in China.

CONCLUSION

This study contributes to improving the current FH detection rate and genetic screening strategies; it provides new directions for treatment, management, and drug development.

Developing a Hybrid Risk Assessment Tool for Familial Hypercholesterolemia: A Machine Learning Study of Chinese Arteriosclerotic Cardiovascular Disease Patients

Background

Familial hypercholesterolemia (FH) is an autosomal-dominant genetic disorder with a high risk of premature arteriosclerotic cardiovascular disease (ASCVD). There are many alternative risk assessment tools, for example, DLCN, although their sensitivity and specificity vary among specific populations. We aimed to assess the risk discovery performance of a hybrid model consisting of existing FH risk assessment tools and machine learning (ML) methods, based on the Chinese patients with ASCVD.

Materials and Methods

In total, 5,597 primary patients with ASCVD were assessed for FH risk using 11 tools. The three best performing tools were hybridized through a voting strategy. ML models were set according to hybrid results to create a hybrid FH risk assessment tool (HFHRAT). PDP and ICE were adopted to interpret black box features.

Results

After hybridizing the mDLCN, Taiwan criteria, and DLCN, the HFHRAT was taken as a stacking ensemble method (AUC_class[94.85 ± 0.47], AUC_prob[98.66 ± 0.27]). The interpretation of HFHRAT suggests that patients aged <75 years with LDL-c >4 mmol/L were more likely to be at risk of developing FH.

Conclusion

The HFHRAT has provided a median of the three tools, which could reduce the false-negative rate associated with existing tools and prevent the development of atherosclerosis. The hybrid tool could satisfy the need for a risk assessment tool for specific populations.

The promising novel therapies for familial hypercholesterolemia

Background

The incidence of premature atherosclerotic cardiovascular disease in familial hypercholesterolemia (FH) is high. In recent years, novel therapeutic modalities have shown significant lipid‐lowering ability. In this paper, we summarize the recent developments in novel therapies for FH via the treatment of different targets and discuss the characteristics of each targeted therapy. Based on the process of protein synthesis, we attempt to summarize the direct‐effect targets including protein, RNA, and DNA.

Methods

For this systematic review, relevant studies are assessed by searching in several databases including PubMed, Web of Science, Scopus, and Google Scholar. The publications of original researches are considered for screening.

Results

Most drugs are protein‐targeted such as molecule‐based and monoclonal antibodies, including statins, ezetimibe, alirocumab, evolocumab, and evinacumab. Both antisense oligonucleotide (ASO) and small interfering RNA (siRNA) approaches, such as mipomersen, vupanorsen, inclisiran, and ARO‐ANG3, are designed to reduce the number of mRNA transcripts and then degrade proteins. DNA‐targeted therapies such as adeno‐associated virus or CRISPR–Cas9 modification could be used to deliver or edit genes to address a genetic deficiency and improve the related phenotype.

Conclusion

While the therapies based on different targets including protein, RNA, and DNA are on different stages of development, the mechanisms of these novel therapies may provide new ideas for precision medicine.

Familial Hypercholesterolemia in Asia Pacific: A Review of Epidemiology, Diagnosis, and Management in the Region

Familial hypercholesterolemia (FH) is a common genetic disease that is estimated to affect at least 15 million people in the Asia Pacific region. Affected individuals are at significantly increased risk of premature atherosclerotic cardiovascular disease. A literature review was undertaken to provide an overview of the epidemiology, diagnosis, and management of FH across the region.Currently, epidemiological data relating to FH are lacking across the Asia Pacific. Of the 15 countries and regions considered, locally conducted studies to determine FH prevalence were only identified for Australia, China, India, and Japan. Although practically all national clinical guidelines for dyslipidemia include some commentary on FH, specific guidelines on the management of FH are available for only one third of the countries and regions evaluated. Estimates of current FH diagnosis rates suggest that most affected individuals remain undiagnosed and untreated. Although innovative medications such as proprotein convertase subtilisin/kexin type 9 inhibitors have been approved and are available in most countries and regions considered, they are currently reimbursed in only one quarter.Despite these shortcomings, there is cause for optimism. Early experience with cascade screening in Hong Kong, India, and Vietnam has proven an effective means of identifying family members of probands, as has a reverse screening of family members of children with FH in China. FH registries are gaining momentum across the region, with registries now established in almost half of the countries and regions evaluated. This review concludes with a Call to Action on FH for Asia Pacific to engage healthcare professionals, improve public awareness, and form national FH alliances, comprising all relevant healthcare professional organizations, as a platform to expedite national quality improvement programs in the management of FH.

Role of PCSK9 Inhibitors in Patients with Familial Hypercholesterolemia

Patients with familial hypercholesterolemia (FH) are at high or very high risk for cardiovascular disease. Those with heterozygous FH (HeFH) often do not reach low-density lipoprotein cholesterol (LDL-C) targets with statin and ezetimibe therapy, and those with homozygous FH (HoFH) usually require additional lipid-modifying therapies. Drugs that inhibit proprotein convertase subtilisin/kexin type 9 (PCSK9) offer a novel approach to reduce LDL-C. The monoclonal antibodies, alirocumab and evolocumab, given by subcutaneous injection every 2 or 4 weeks produce reductions in LDL-C of 50% to 60% in patients with HeFH, allowing many of them to achieve their LDL-C goals. Patients with HoFH show a reduced and more variable LDL-C response, which appears to depend on residual LDL receptor activity, and those with receptor-negative mutations may show no response. Inclisiran is a long-acting small interfering RNA therapeutic agent that inhibits the synthesis of PCSK9. Subcutaneous doses of 300 mg can reduce LDL-C by more than 50% for at least 6 months and the responses in HeFH and HoFH patients are similar to those achieved with monoclonal antibodies. These PCSK9 inhibitors are generally well tolerated and they provide a new opportunity for effective treatment for the majority of patients with FH.

The prevalence and related factors of familial hypercholesterolemia in rural population of China using Chinese modified Dutch Lipid Clinic Network definition

Background

Familial hypercholesterolemia (FH) is a common monogenic disease, while studies about the epidemiology for the general population in China was scarce. Aim of the study was to estimate the prevalence of FH and explore related factors by the Chinese modified Dutch Lipid Clinic Network (DLCN) definition.

Methods

A total of 39,205 participants (15,463 males and 23,742 females) aged 18–79 years old were enrolled from the Henan Rural Cohort Study. FH was defined by the Chinese modified DLCN definition, and score > 5 was classified as FH. Logistic regression analysis was used to calculate the odds ratio and 95% confidence interval.

Results

Crude prevalence of probable/definite FH was 0.35% (0.29–0.41%), estimated by the Chinese modified DLCN definition. Prevalence in female was 0.38%, and in male, it was 0.32%. Age-standardized prevalence in female increased significantly around the age of 50 years. Moreover, there were no FH patients getting low-density lipoprotein cholesterol controlled to the recommended level. Multivariate logistic regression identified that older, overweight/obesity were positively associated with FH.

Conclusions

The current study indicated that FH was not rare in rural area of China (1 in 286). Effective early detection and timely control of FH must be strengthened to reduce disease burden.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7212-4) contains supplementary material, which is available to authorized users.

Effects of familial hypercholesterolemia-associated genes on the phenotype of premature myocardial infarction

Background

The incidence of premature myocardial infarction (PMI) has gradually increased in recent years. Genetics plays a central role in the development of PMI. Familial hypercholesterolemia (FH) is one of the most common genetic disorders of cholesterol metabolism leading to PMI.

Objective

This study investigated the relationship between FH-associated genes and the phenotype of PMI to clarify the genetic spectrum of PMI diseases.

Method

This study enrolled PMI patients (n = 225) and detected the mutations in their FH-associated genes (LDLR, APOB, PCSK9, LDLRAP1) by Sanger sequencing. At the same time, patients free of PMI (non-FH patients, n = 56) were enrolled as control, and a logistic regression analysis was used to identify risk factors associated with PMI. The diagnosis of FH was confirmed using “2018 Chinese expert consensus of FH screening and diagnosis” before the prevalence and clinical features of FH were analyzed.

Results

Pathogenic mutations in LDLR, APOB, PCSK9 and LDLRAP1 genes were found in 17 of 225 subjects (7.6%), and all mutations were loss of function (LOF) and heterozygous. The genotype-phenotype relationship of patients carrying FH-associated mutations showed high heterogeneity. The logistic regression analysis showed that the smoking history, obesity and the family history of premature CHD were independent risk factors of PMI. In this study, a total of 19 patients (8.4%) were diagnosed as FH, and the proportion of smoking subjects in FH patients was higher than that in non-FH patients.

Conclusions

FH-associated gene mutations were present in about 7.6% of Chinese patients with PMI. In addition to genetic factors, smoking history, lifestyle and other environmental factors may play a synergistic role in determining the phenotype of PMI.

Trial registration

Essential gene mutation of cholesterol metabolism in patients with premature myocardial infarction. ChiCTR-OCH-12002349.Registered 26 December 2014, http://www.chictr.org.cn/showproj.aspx?proj=7201.

Current Status of Familial Hypercholesterolemia in China: A Need for Patient FH Registry Systems

Background: Familial hypercholesterolemia (FH) greatly facilitates the development of cardiovascular disease (CVD). Without timely treatment, the incidence of coronary heart disease (CHD) in patients with FH is 3 to 4 times that in non-FH patients, and the onset of CVD would be advanced by approximately 10 years. There is ample evidence that the diagnosis and adequate treatment of FH are not properly considered for all ethnicities. The monogenic cause of FH includes apolipoprotein B (APOB), low-density lipoprotein receptor (LDLR), and proprotein convertase subtilisin/kexin 9 (PCSK9). There are approximately 2,765,420 to 6,913,550 cases of potential heterozygous FH (HeFH) and 2,205 to 4,609 cases of potential homozygous FH (HoFH) in China. Nevertheless, China lacks clinical diagnostic criteria specific to Chinese patients, such that most FH patients cannot be diagnosed until middle age or after their first cardiovascular event, thus precluding early treatment. Objective: This article explores the gene mutations, diagnosis and treatment of FH patients in China. Following the implementation of the two-child policy, there is a need to establish Chinese FH registry systems and genetic databases and to address the challenges in conducting cascade screening and long-term management. Conclusion: Advocating the establishment of FH registry systems and databases is an important rate-limiting step in improving long-term prognosis in FH patients, so that joint efforts of clinical experts and public communities are required. We recommend a process flow from case identification to entry into the registry system, and the widespread use of the system in clinical applications can provide the best treatment guidance for medical practice.