Large-Scale Screening for Monogenic and Clinically Defined Familial Hypercholesterolemia in Iceland.

Objective: Familial hypercholesterolemia (FH) is traditionally defined as a monogenic disease characterized by severely elevated LDL-C (low-density lipoprotein cholesterol) levels. In practice, FH is commonly a clinical diagnosis without confirmation of a causative mutation. In this study, we sought to characterize and compare monogenic and clinically defined FH in a large sample of Icelanders. Approach and Results: We whole-genome sequenced 49 962 Icelanders and imputed the identified variants into an overall sample of 166 281 chip-genotyped Icelanders. We identified 20 FH mutations in LDLR, APOB, and PCSK9 with combined prevalence of 1 in 836. Monogenic FH was associated with severely elevated LDL-C levels and increased risk of premature coronary disease, aortic valve stenosis, and high burden of coronary atherosclerosis. We used a modified version of the Dutch Lipid Clinic Network criteria to screen for the clinical FH phenotype among living adult participants (N=79 058). Clinical FH was found in 2.2% of participants, of whom only 5.2% had monogenic FH. Mutation-negative clinical FH has a strong polygenic basis. Both individuals with monogenic FH and individuals with mutation-negative clinical FH were markedly undertreated with cholesterol-lowering medications and only a minority attained an LDL-C target of <2.6 mmol/L (<100 mg/dL; 11.0% and 24.9%, respectively) or <1.8 mmol/L (<70 mg/dL; 0.0% and 5.2%, respectively), as recommended for primary prevention by European Society of Cardiology/European Atherosclerosis Society cholesterol guidelines. Conclusions: Clinically defined FH is a relatively common phenotype that is explained by monogenic FH in only a minority of cases. Both monogenic and clinical FH confer high cardiovascular risk but are markedly undertreated.

Racial Disparities in Modifiable Risk Factors and Statin Usage in Black Patients With Familial Hypercholesterolemia.

Background Black men and women are at higher risk for, and suffer greater morbidity and mortality from, atherosclerotic cardiovascular disease (ASCVD) compared with adults of European Ancestry (EA). Black patients with familial hypercholesterolemia are at particularly high risk for ASCVD complications because of lifelong exposure to elevated levels of low-density-lipoprotein cholesterol. Methods and Results This retrospective study analyzed ASCVD prevalence and risk factors in 808 adults with heterozygous familial hypercholesterolemia from 5 US-based lipid clinics, and compared findings in Black versus EA patients. Multivariate logistic regression models were used to determine the strongest predictors of ASCVD as a function of race. No significant difference was noted in the prevalence of ASCVD in Black versus EA patients with familial hypercholesterolemia (39% versus 32%, respectively; P=0.15). However, Black versus EA patients had significantly greater prevalence of modifiable risk factors, including body mass index (mean, 32±7 kg/m2 versus 29±6 kg/m2; P<0.001), hypertension (82% versus 50%; P<0.001), diabetes (39% versus 15%; P<0.001), and current smoking (16% versus 8%; P=0.006). Black versus EA patients also had significantly lower usage of statins (61% versus 73%; P=0.004) and other lipid-lowering agents. In a fully adjusted multivariate model, race was not independently associated with ASCVD (odds ratio, 0.92; 95% CI, 0.60-1.49; P=0.72). Conclusions The strongest predictors of ASCVD in Black patients with familial hypercholesterolemia were hypertension and cigarette smoking. These data support wider usage of statins and other lipid-lowering therapies and greater attention to modifiable risk, specifically blood pressure management and smoking cessation.

Particularidades genéticas y bioquímicas de la hipercolesterolemia familiar en el suroeste de la Península Ibérica / Genetics and biochemistry of familial hypercholesterolemia in Southwest of the Iberian Peninsula

Hasta el momento, la mayor parte de los casos de hipercolesterolemia familiar (60-80%) se atribuyen a variantes patogénicas en el gen LDLR. Solo un 1-5% de los casos se produce por variantes en el gen APOB y un 0-3% por variantes en el gen PCSK9. Existen gran variedad en mutaciones patogénicas conocidas del gen LDLR mientras que, para las que afectan al gen APOB, la de mayor incidencia es p.Arg3527Gln, descrita predominantemente en poblaciones de Centroeuropa y América del Norte. En la Península Ibérica el gen predominante afectado es el del receptor de LDL, similar al resto del mundo, siendo la afectación del gen APOB descrita en individuos del noroeste y anecdótica en el resto del territorio. Analizamos genéticamente la población asistida en el primer año de una consulta de lípidos del suroeste de España con puntuación≥6 puntos de las clínicas de lípidos holandesas y describimos los hallazgos genéticos, bioquímicos y clínicos. Los primeros hallazgos muestran indicios de una posible mayor prevalencia de pacientes con mutación en el gen APOB respecto a otros territorios. Encontramos hechos históricos que darían una posible explicación a este hecho, apoyando así dicha presunción.(AU)

So far, most cases of hypercholesterolaemia (60-80%) are attributed to pathogenic variants in the LDLR gene. Only 1-5% of cases are caused by variants in the APOB gene, and 0-3% by variants in the PCSK9 gene. There is a large variety in known pathogenic mutations of the LDLR gene, while for those affecting the APOB gene, the highest incidence is p.Arg3527Gln, described predominantly in Central European and North American populations. In the Iberian Peninsula the predominant gene affected is that of the LDL receptor, similar to the rest of the world, with the involvement of the APOB gene being described in individuals from the northwest, and anecdotal in the rest of the territory. A genetics analysis was performed on the population attending the first year of a lipid clinic in southwestern Spain with a 6-point score from the Dutch lipid clinics. The genetic, biochemical and clinical findings are described. The first findings show indications of a possible higher prevalence of patients with mutation in the APOB gene compared to other territories. Historical evidence is presented that could give a possible explanation to this, thus supporting the assumption.(AU)

Dietary intake and lipid levels in Norwegian and Spanish children with familial hypercholesterolemia.

BACKGROUND AND AIMS: Both the Nordic and Mediterranean diets claim to have a beneficial effect on lipid metabolism and cardiovascular prevention. The objective of this study was to compare diets consumed by children with FH at the time of diagnosis in Norway and Spain and to study their relationship with the lipid profile. METHODS AND RESULTS: In this cross-sectional study, we appraised the dietary intake in children (4-18 years old) with (n = 114) and without FH (n = 145) from Norway and Spain. We compared Nordic and Mediterranean diet composition differences and determined the association between food groups and lipid profiles. RESULTS: The Spanish FH group had a higher intake of total fats (mainly monounsaturated fatty acids (MUFAs)), cholesterol and fibre, but a lower intake of polyunsaturated fatty acids (PUFAs) compared to the Norwegian FH group. The Norwegian children consumed more rapeseed oil, low-fat margarine and whole grains and less olive oil, eggs, fatty fish, meat, legumes and nuts. In the Norwegian FH group, fat and MUFAs were directly correlated with total cholesterol, low-density lipoprotein cholesterol and apolipoprotein B and inversely correlated with high-density lipoprotein (HDL-C). In Spanish children with FH, the intake of fats (mainly MUFAs) was directly associated with HDL-C and apolipoprotein A1. CONCLUSIONS: Despite a similar lipid phenotype, diets consumed by children with FH in Norway and Spain have significant differences at time of diagnosis. Nutrition advice should be more adapted to local intake patterns than on specific nutrient composition.

Hui: a partnership in practice in familial hypercholesterolemia.

AIMS: To empower a large whanau (extended family) with a history of severe premature heart disease and familial hypercholesterolemia (FH). METHODS: After broad consultation a Hui was held to discuss how to better manage this issue to ensure present and future generations were appropriately screened and treated. RESULTS: A closed social media page with detailed information on how to manage and screen FH that includes a family tree (for those who consent) has been created. The whanau, facilitated by health professionals, have ownership of their health. This has led to an uptake of screening and treatment for FH with whanau who are now able to inform local health professionals about their disorder. CONCLUSION: FH is the most common dominant genetic disorder in humans and causes premature heart disease and death. Current approaches are dependent on index patients presenting for cascade screening and do not incorporate the needs and views of the extended whanau. Establishing a partnership with the whanau and giving back control of health information is crucial to ensure equity. A national systematic programme is also needed to manage this condition with important health outcomes that can be averted if treated from a young age.

Cascade Screening for Familial Hypercholesterolemia in South Africa: The Wits FIND-FH Program.

OBJECTIVE: Due to gene founder effects, familial hypercholesterolemia (FH) has a prevalence of ≈1:80 in populations of Afrikaner ancestry and is a major contributor to premature atherosclerotic cardiovascular disease in South Africans of Jewish and Indian descent. No systematic program exists to identify these families. Furthermore, information regarding FH prevalence in Black Africans is sparse. The Wits FIND-FH program was initiated in late 2016 to address these issues. Approach and Results: Based on index subjects with definite or probable FH, first-degree relatives were contacted, informed consent obtained, and targeted medical history, physical examination, and blood samples collected. In patients with likely FH using the Simon Broome criteria, DNA analysis for LDLR (low-density lipoprotein receptor), APOB (apolipoprotein B), PCSK9 (proprotein convertase subtilisin/kexin type 9), and LDLRAP1 (LDLR adaptor protein 1) variants was analyzed by next-generation sequencing. Of the initial 700 subjects screened of whom 295 (42%) were index cases, 479 (68.4%) were clinically diagnosed with probable or definite FH. Genetic analysis confirmed 285 of 479 (59.5%) as having variants consistent with FH. Three subjects met the clinical diagnosis for homozygous FH, but DNA analysis revealed a further 34 patients, including 4 Black African subjects, with ≥2 FH-causing variants. CONCLUSIONS: Using phenotype cascade screening, the Wits FIND-FH program has screened an average of 30 subjects monthly of whom 68% had a clinical diagnosis of FH with ≈60% genetically confirmed. The program is identifying a small but growing number of Black South Africans with FH. Interestingly, 37 subjects (7.7%) who underwent DNA testing were found to have ≥2 FH-causing variants.

Worldwide Prevalence of Familial Hypercholesterolemia: Meta-Analyses of 11 Million Subjects.

BACKGROUND: Despite the greater prevalence of familial hypercholesterolemia (FH) in subjects with ischemic heart disease (IHD), premature IHD, and severe hypercholesterolemia (low-density lipoprotein ≥190 mg/dl), overall prevalence estimates are not available. OBJECTIVES: The aim of this study was to provide worldwide estimates of FH prevalence in subjects with IHD, premature IHD, and severe hypercholesterolemia compared with those in the general population. METHODS: In this systematic review and meta-analyses, Embase, PubMed, and the Web of Science were searched until June 3, 2019, for peer-reviewed papers and conference abstracts reporting heterozygous FH prevalence in nonfounder populations, revealing 104 studies eligible for inclusion. RESULTS: Estimates of FH prevalence were pooled using random-effects meta-analyses and were 0.32% (95% confidence interval [CI]: 0.26% to 0.39% [corresponding to 1:313]) among 10,921,310 unique subjects in the general population (33,036 patients with FH) on the basis of 44 studies, 3.2% (95% CI: 2.2% to 4.3% [1:31]) among 84,479 unique subjects with IHD (2,103 patients with FH) on the basis of 28 studies, 6.7% (95% CI: 4.9% to 8.7% [1:15]) among 31,316 unique subjects with premature IHD (1,471 patients with FH) on the basis of 32 studies, and 7.2% (95% CI: 4.6% to 10.8% [1:14]) among 17,728 unique subjects with severe hypercholesterolemia (920 patients with FH) on the basis of 7 studies. FH prevalence in the general population was similar using genetic versus clinical diagnoses. Seventeen of 195 countries (9%) in the world have reported FH prevalence for the general population, leaving 178 (91%) countries in the world with unknown prevalence. CONCLUSIONS: Compared with 1:313 among subjects in the general population, FH prevalence is 10-fold higher among those with IHD, 20-fold higher among those with premature IHD, and 23-fold higher among those with severe hypercholesterolemia. The prevalence of FH is unknown in 90% of countries in the world.

Familial hypercholesterolemia in China half a century: A review of published literature.

AIMS: To investigate the status of familial hypercholesterolemia (FH) research and the characteristics of patients with FH in China. METHODS: Published papers in Chinese or English language from PubMed, SinoMed and CNKI databases from 1971 to March 2018 were searched using 'Familial hypercholesterolemia', 'Chinese' and 'Han' as keywords. A systematic review of studies on familial hypercholesterolemia was then conducted. RESULTS: A total of 391 articles were found, in which 22% were in English and 78% were in Chinese; approximately 43% are case reports and 34% are genetic reports according to the study type; 52% discussed the status of the disease and 11% investigated the subclinical status according to the study content. Furthermore, 96% of the articles were published by tertiary hospitals and 46% were conducted by cardiologists. The first expert consensus was issued in February 2018. Of the 163 case reports published before 2018, 48.7% used the Chinese FH clinical diagnostic criteria and 34.4% did not clearly indicate the diagnostic criteria. The incidence rates of low-density lipoprotein receptor (LDLR) and apolipoprotein B (APOB) mutations were 82% and 9%, and proprotein convertase subtilisin/kexin type 9 (PCSK9) mutations were rare in Chinese patients with FH. However, the data on lipid-lowering treatment rates, compliance rates and cardiovascular events in FH remain insufficient. CONCLUSIONS: Large-scale epidemiological investigation of FH has not been demonstrated, the recognition of FH remains rudimentary, and the guidelines are incomplete in China. The diagnosis and management of Chinese FH needs to be improved.

Screening of common genetic variants in the APOB gene related to familial hypercholesterolemia in a Saudi population: A case-control study.

Familial hypercholesterolemia (FH) is a monogenic dominant inherited disorder of lipid metabolism characterized by elevated low-density lipoprotein levels, and is mainly attributable to mutations in low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), and proportein convertase subtilisin/kexin type 9 (PCSK9) genes. Next-generation and exome sequencing studies have primarily involved genome-wide association analyses, and meta-analyses and next-generation studies examined a few single-nucleotide polymorphisms (rs151009667 and Val2095Glu) in the ApoB gene. The present study was conducted to investigate the association of APOB and patients with FH in a Saudi population.We genotyped 100 patients with FH and 100 controls for 2 polymorphisms in APOB using polymerase chain reaction-restriction fragment length polymorphism, followed by 3% agarose gel electrophoresis. The strength of the association between the genotype and allele frequencies with the risk of developing FH was evaluated. Clinical details and genotype analysis results were recorded.For the rs151009667 polymorphism, 18% of the CT genotypes were observed only in patients with FH. There was a positive association between CT and CC (odds ratio [OR] 45.07 [95% conflict of interest (CI), 2.67-759.1]; P = .0001) and between T and C (OR 87.8 [95% CI, 5.34-144.2]; P < .0001). However, no Val2095Glu mutations were found in patients with FH or controls. There was also no correlation between clinical characteristics and the rs151009667 polymorphism.In conclusion, we confirmed the association between the rs151009667 polymorphism and FH in a Saudi population. The Val2095Glu novel variant did not appear in either patients with FH or controls. Similar studies should be performed in different ethnic populations to rule out the role of this polymorphism in FH.

Spectrum of mutations of familial hypercholesterolemia in the 22 Arab countries.

BACKGROUND AND AIMS: Familial hypercholesterolemia (FH) is an inherited genetic disorder of lipid metabolism characterized by a high serum LDL-cholesterol profile and xanthoma formation, and FH increases the risk of premature atherosclerosis and cardiovascular disease (CVD). Mutations in the low-density lipoprotein (LDLR), apolipoprotein B (APOB), proprotein convertase subtilisin/kexin 9 (PCSK9), and LDLRAP1 genes have been associated with FH. Although FH is a major risk for CVD, the disease prevalence and its underlying molecular basis in the 22 Arab countries are still understudied. This study aimed to analyze all peer-reviewed studies related to the prevalence of FH and its causative mutations in the 22 Arab countries. METHODS: We searched five literature databases (Scopus, Science Direct, Web of Science, PubMed, and Google Scholar) from inception until June 2018, using all possible search terms to capture all of the genetic and prevalence data related to Arab patients with FH. RESULTS: A total of 5,484 titles and abstracts were identified; 51 studies met our inclusion criteria for the final systematic review. Fifty-one mutations in Arab patients with FH were identified in only eight Arab countries; 47 were identified in the LDLR gene, two in the PCSK9 gene, and two in LDLRAP1 gene. Twenty mutations in the LDLR gene were distinctive to Arab patients. A few studies reported prevalence estimates, ranging from 0.4% to 6.8%. CONCLUSIONS: This is the first systematic review to dissect the up-to-date status of the genetic epidemiology of Arab patients with FH. It seems that FH is underdiagnosed and that its prevalence is understudied due to the dearth of published information about Arab patients with FH. Therefore, there is a need for well-controlled genetic epidemiological studies on Arab patients with FH.

Familial hypercholesterolemia prevalence in an admixed racial society: Sex and race matter. The ELSA-Brasil.

BACKGROUND AND AIMS: Familial hypercholesterolemia (FH) is a genetic disorder associated with high cardiovascular burden of disease. FH prevalence may vary widely across populations and data in race/ethnically diverse and admixed populations is scarce. ELSA-Brasil epidemiology may be widely generalizable in this regard, and we calculated the ELSA-Brasil FH prevalence and its variation according to age, sex and race/ethnicity. METHODS: In 14,460 individuals aged from 35 to 75 years from the ELSA-Brasil cohort baseline, we classified FH according to the Dutch Lipid Clinic Network criteria score ≥6 (probable and definite FH). LDL-C levels were adjusted for statin use. We calculated the overall ELSA-Brasil FH prevalence and the weighted prevalence for age, sex and race/ethnic categories. We extrapolated those frequencies to the Brazilian population weighting for age-sex-race/ethnicity according to the 2015 Statistics and Geography Brazilian Institute survey. RESULTS: The overall FH prevalence per 1000 individuals in ELSA-Brasil was 3.8 (2.9, 4.9) or 1 in 263. The age/sex/race-ethnicity-weighted FH prevalences were: male, 3.0 (1.7, 4.4) or 1 in 333; female, 4.1 (3.0, 5.2) or 1 in 244 (p<0.001). White race prevalence was 2.4 (1.9, 3.0) or 1 in 417; Brown, 4.9 (4.0, 5.9) or 1 in 204; and Black 6.4 (41.1, 8.7) or 1 in 156 (p<0.001). The weighted extrapolation for the Brazilian population derived similar magnitude frequencies. CONCLUSIONS: FH affects 1 in 263 in ELSA-Brasil and affects disproportionally more Brown (1 in 204), and Black (1 in 156), than White (1 in 417). Weighted extrapolation for the Brazilian population derived similar magnitude frequencies.

Health literacy in familial hypercholesterolemia: A cross-national study.

Background High rates of inadequate health literacy are associated with maladaptive health outcomes in chronic disease including increased mortality and morbidity rates, poor treatment adherence and poor health. Adequate health literacy may be an important factor in the effective treatment and management of familial hypercholesterolemia, and may also be implicated in genetic screening for familial hypercholesterolemia among index cases. The present study examined the prevalence and predictors of health literacy in familial hypercholesterolemia patients attending clinics in seven countries. Design Cross-sectional survey. Methods Consecutive FH patients attending clinics in Australia, Brazil, China, Hong Kong, Malaysia, Taiwan and the UK completed measures of demographic variables (age, gender, household income and highest education level) and a brief three-item health literacy scale. Results Rates of inadequate health literacy were lowest in the UK (7.0%), Australia (10.0%), Hong Kong (15.7%) and Taiwan (18.0%) samples, with higher rates in the Brazil (22.0%), Malaysia (25.0%) and China (37.0%) samples. Income was an independent predictor of health literacy levels, accounting for effects of age. Health literacy was also independently related to China national group membership. Conclusions Findings indicate non-trivial levels of inadequate health literacy in samples of familial hypercholesterolemia patients. Consistent with previous research in chronic illness, inadequate health literacy is related to income as an index of health disparities. Chinese familial hypercholesterolemia patients are more likely to have high rates of inadequate health literacy independent of income. Current findings highlight the imperative of education interventions targeting familial hypercholesterolemia patients with inadequate health literacy.

Familial hypercholesterolemia in Chinese patients with premature ST-segment-elevation myocardial infarction: Prevalence, lipid management and 1-year follow-up.

BACKGROUND: Familial hypercholesterolemia (FH), characterized by elevated plasma low-density lipoprotein-cholesterol (LDL-C) levels and premature coronary artery disease (CAD), remains mostly underdiagnosed and undertreated. We investigated the prevalence of clinical FH among Chinese patients with premature ST-segment-elevation myocardial infarction (STEMI) and one-year follow-up on their lipid management and cardiovascular events. METHODS: Four hundred and ninety-eight premature STEMI patients (363men) were enrolled. FH patients were identified using the Dutch Lipid Clinic Network Criteria. Lipid management and cardiovascular events in all patients were assessed. RESULTS: Nineteen patients (3.8%) were diagnosed as definite/probable FH, 211 (42.4%) as possible FH and 268 (53.8%) as unlikely FH. All patients were divided into two main groups: unlikely FH (0-2 points) and possible FH (≥3 points). Possible FH patients were younger (50.1 years vs. 53.5 years) with higher NT-proBNP level (3014.15 pg/mL vs. 2326.25 pg/mL), occurrence of multi-vessel CAD (37.4% vs. 18.3%), lower LVEF (47% vs. 49%) and more severe Killip classification (Class 3, 20.0% vs. 9.7%). Follow-up data were available for 203 patients from the possible FH group and 243 patients from the unlikely FH group. High intensity statin intake status (%) of possible FH vs. unlikely FH was as follows: 1) on admission: 4.8% vs. 0.4%; 2) at discharge: 10.4% vs. 1.6% and 3) at one year follow-up: 5.4% vs. 0.8%. A significantly low percentage of possible FH patients (18.7% vs. 51.4%) achieved target LDL-C levels. There were no significant differences in MACE defined as a composite of cardiogenic shock or Class IV heart failure, recurrent MI, cardiovascular-related rehospitalization, TLR and CV death between the two groups. However, the proportion of cardiogenic shock or Class IV heart failure was significantly higher in possible FH patients group (5.9% vs.1.2%). CONCLUSION: Clinical diagnosis of possible FH is common in Chinese patients with premature STEMI. A low proportion of FH patients were prescribed high intensity statins. Despite aggressive cholesterol-lowering drugs, a significantly lower proportion of FH patients achieved LDL-C targets compared to unlikely FH patients. Possible FH patients were younger with a significantly higher occurrence of multi-vessel CAD and impaired cardiac function.

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

BACKGROUND: Reverse cascade screening is not commonly employed to detect new cases of familial hypercholesterolemia (FH). We aimed to assess the outcome of this screening strategy in families in which the probands were children with severe FH. HYPOTHESIS: Reverse cascade screening is an effective method to detect new patients with FH. METHODS: Reverse cascade screening was undertaken starting from 47 index children with severe hypercholesterolemia; 39 were homozygous/compound heterozygous FH and 8 were heterozygous FH. Available parents, siblings, and second-degree relatives were contacted and screened. RESULTS: From the 39 cases of homozygous/compound heterozygous FH, 80 first-degree family members were available for screening; 70 were parents and 10 were siblings. All first-degree relatives screened were genetically diagnosed with FH. None of the parents had been treated with statins at the time of diagnosis, and 10 (12.7%) had premature coronary artery disease. Additionally, 46 second-degree relatives were screened, of which 41 (89%) were diagnosed with FH. From the 8 heterozygous FH children, 17 first- and second-degree relatives were screened and 12 new cases of FH were also diagnosed. Hence, the overall diagnostic yield of screening was 2.8 new cases of FH per index case. CONCLUSIONS: Reverse cascade screening is a highly effective method for diagnosing new cases of FH in parents, siblings, and second-degree relatives of index children with severe FH.

Health disparities among adult patients with a phenotypic diagnosis of familial hypercholesterolemia in the CASCADE-FH™ patient registry.

BACKGROUND AND AIMS: Most familial hypercholesterolemia (FH) patients remain undertreated, and it is unclear what role health disparities may play for FH patients in the US. We sought to describe sex and racial/ethnic disparities in a national registry of US FH patients. METHODS: We analyzed data from 3167 adults enrolled in the CAscade SCreening for Awareness and DEtection of Familial Hypercholesterolemia (CASCADE-FH) registry. Logistic regression was used to evaluate for disparities in LDL-C goals and statin use, with adjustments for covariates including age, cardiovascular risk factors, and statin intolerance. RESULTS: In adjusted analyses, women were less likely than men to achieve treated LDL-C of <100 mg/dL (OR 0.68, 95% CI, 0.57-0.82) or ≥50% reduction from pretreatment LDL-C (OR 0.79, 95% CI, 0.65-0.96). Women were less likely than men to receive statin therapy (OR, 0.60, 95% CI, 0.50-0.73) and less likely to receive a high-intensity statin (OR, 0.60, 95% CI, 0.49-0.72). LDL-C goal achievement also varied by race/ethnicity: compared with whites, Asians and blacks were less likely to achieve LDL-C levels <100 mg/dL (Asians, OR, 0.47, 95% CI, 0.24-0.94; blacks, OR, 0.49, 95% CI, 0.32-0.74) or ≥50% reduction from pretreatment LDL-C (Asians, OR 0.56, 95% CI, 0.32-0.98; blacks, OR 0.62, 95% CI, 0.43-0.90). CONCLUSIONS: In a contemporary US population of FH patients, we identified differences in LDL-C goal attainment and statin usage after stratifying the population by either sex or race/ethnicity. Our findings suggest that health disparities contribute to the undertreatment of US FH patients. Increased efforts are warranted to raise awareness of these disparities.

The genetic spectrum of familial hypercholesterolemia in the central south region of China.

BACKGROUND AND AIMS: Familial hypercholesterolemia (FH) is the most common and severe autosomal dominant lipid metabolism dysfunction, which causes xanthoma, atherosclerosis and coronary heart disease. Earlier studies showed that mutations in LDLR, APOB and PCSK9 cause FH. Although more than 75% of the population in Europe has been scrutinized for FH-causing mutations, the genetic diagnosis proportion among Chinese people remains very low (less than 0.5%). The aim of this study was to perform a survey and mutation detection among the Chinese population. METHODS: 219 FH patients from the central south region of China were enrolled. After extracting DNA from circulating lymphocytes, we used direct DNA sequencing to screen each exon of LDLR, APOB and PCSK9. All detected variants were predicted by Mutationtaster, Polyphen-2 and SIFT to assess their effects. RESULTS: In total, 43 mutations were identified from 158 FH patients. Among them, 11 novel mutations were found, including seven LDLR mutations, two APOB mutations and two PCSK9 mutations. Moreover, five common mutations in LDLR were detected. We geographically marked their distributions on the map of China. CONCLUSIONS: The spectrum of FH-causing mutations in the Chinese population is refined and expanded. Along with future studies, our study provides the necessary data as the foundation for the characterization of the allele frequency distribution in the Chinese population. The identification of more LDLR, APOB and PCSK9 novel mutations may expand the spectrum of FH-causing mutations and contribute to the genetic diagnosis and counseling of FH patients.

Clinical determinants and treatment gaps in familial hypercholesterolemia: Data from a multi-ethnic regional health service.

Background Familial hypercholesterolemia is characterized by markedly increased low-density lipoprotein cholesterol and risk for premature atherosclerotic cardiovascular disease. Models of care vary and reflect differing health policies and resources. The availability of electronic databases may enable better identification and assessment of familial hypercholesterolemia in the community. Methods A regional healthcare database was utilized to identify patients with a high probability of familial hypercholesterolemia, clinically defined by age-dependent-peak low-density lipoprotein cholesterol cutoffs and exclusion of secondary causes of severe hypercholesterolemia. Clinical characteristics, low-density lipoprotein cholesterol goal attainment, and treatment gaps were investigated. Results Probable familial hypercholesterolemia was diagnosed in 1932 of 685,314 individuals (1:355; median age 47 years). Atherosclerotic cardiovascular disease was present in 16.3% of adults (38% in males aged 50-74 years). Median peak low-density lipoprotein cholesterol was 264 mg/dl (interquartile range 252-288). Statins and/or ezetimibe were prescribed to 83% of patients and high-intensity statins to 53%, whereas prescriptions were filled in 57% and 40% cases respectively over the last six months, p < 0.001. Treatment gaps were wider among ethnic minorities, younger individuals, and those without atherosclerotic cardiovascular disease. Low-density lipoprotein cholesterol < 100 mg/dl was attained in 10.1% overall and 28.7% of those with atherosclerotic cardiovascular disease. Predictors of low-density lipoprotein cholesterol goal attainment included recent issue of high-intensity statins, presence of atherosclerotic cardiovascular disease, diabetes, older age and lack of smoking. Conclusions The population with high probability for familial hypercholesterolemia was characterized by low attainment of low-density lipoprotein cholesterol treatment goals despite high prescription rates of lipid-lowering medications. Low utilization of intensified therapies, non-adherence, and ethnic disparities were contributing factors. These findings emphasize the need to improve awareness and quality of care of familial hypercholesterolemia in the community.

Familial Hypercholesterolemia Phenotype in Chinese Patients Undergoing Coronary Angiography.

OBJECTIVE: Familial hypercholesterolemia (FH) is characterized by an elevated low-density lipoprotein cholesterol and increased risk of premature coronary artery disease. However, the general picture and mutational spectrum of FH in China are far from recognized, representing a missed opportunity for the investigation. APPROACH AND RESULTS: A total of 8050 patients undergoing coronary angiography were enrolled. The diagnosis of clinical FH was made using Dutch Lipid Clinic Network criteria, and the information of relatives was obtained by inquiring for the probands or from their own medical records of certain clinics/hospitals. Molecular analysis of FH was performed using target exome sequencing in LDLR (low-density lipoprotein cholesterol receptor gene), APOB (apolipoprotein B gene), and PCSK9 (proprotein convertase subtilisin/kexin type 9 gene). As a result, 3.5% of the patients with definite/probable FH phenotype (definite 1.0% and probable 2.5%) were identified. Women FH had fewer premature coronary artery disease (women <60, or men <55 years of age) when compared with men FH (70.6% versus 82.7%; P<0.001), whereas angiographic extension of coronary artery disease was significantly increased with FH diagnosis in both men and women (P<0.001). Patterns of medication use in definite/probable FH were as follows: nontreated, 20.6%; low intensity, 6.0%; moderate intensity, 68.3%; and high intensity, 5.0%. However, none of them had achieved the low-density lipoprotein cholesterol <100 mg/dL. Additionally, mutational analysis was performed in 245 definite/probable FH cases, and risk variants were identified in 115 patients, giving a detection rate of 46.9%. CONCLUSIONS: We showed firsthand a common identification but poor treatment of patients with FH phenotype in Chinese coronary angiography patients. Genetic data in our FH cases might contribute to update the frequency and spectrum of Chinese FH scenarios.

Familial defective apolipoprotein B-100: A review.

Familial defective apolipoprotein B-100 (FDB) is an autosomal dominant genetic disorder of lipid metabolism associated with hyperlipidemia and elevated risk for atherosclerosis. FDB is caused by mutations in APOB reducing the binding affinity between apolipoprotein B-100 and the low-density lipoprotein receptor. Population studies suggest that approximately 0.1% of Northern Europeans and US Caucasians carries the R3500Q variant in APOB most commonly associated with FDB; in addition, the APOB R3500 W variant is known to make a significant contribution to familial hypercholesterolemia (FH) among East Asians. However, the elevation of plasma low-density lipoprotein cholesterol observed in FDB is frequently milder than that of FH due to mutations in LDLR, and FDB is subsequently underdiagnosed according to standard FH diagnostic criteria.