Familial hypercholesterolemia:Current limitations and future breakthroughs

Familial hypercholesterolemia(FH)is characterized by elevated low-density lipoprotein cholesterol levels due to genetic mutations,presenting with xanthomas,corneal arch,and severe cardiovascular diseases.Early identification,diagnosis,and treatment are crucial to prevent severe complications like acute myocardial infarction.Statins are the primary treatment,supplemented by Ezetimibe and proprotein convertase subtilisin/kexin type 9 inhibitors,though their effectiveness can be limited in severe cases.Over 90%of FH cases remain undiagnosed,and current treatments are often inadequate,underscoring the need for improved diagnostic and management systems.Future strategies include advancements in gene testing,precision medicine,and novel drugs,along with gene therapy approaches like AAV-mediated gene therapy and clustered regularly interspaced short palindromic repeats.Lifestyle modifications,including health education,dietary control,and regular exercise,are essential for managing FH and preventing related diseases.Research into FH-related gene mutations,especially LDLR,is critical for accurate diagnosis and effective treatment.

The Prevalence of Heterozygous Familial Hypercholesterolemia among Adult Filipino Patients with Dyslipidemia at Universidad de Santa Isabel Health Services Department: An Observational Descriptive Prospective Study

Objectives: It is to determine the prevalence of familial hypercholesterolemia (FH) among adult Filipino patients with dyslipidemia at Universidad de Santa Isabel Health Services Department in one year. Methods: An observational descriptive prospective study involves Filipino patients, aged 19 years and older, with dyslipidemia. The Dutch Lipid Network (DLN) Criteria was used to diagnose FH. Prevalence data and categorical variables were expressed as percentages, while continuous variables were reported as mean and standard deviations. Results: 529 patients were included in the study. 302 were females, and 227 were males. 180 (34%) scored Unlikely, 100 (19%) scored Probable, 185 (35%) scored Possible, and 64 (12%) were classified under Definite Familial Hypercholesterolemia. Most of the patients diagnosed with definite FH did not have diabetes, cerebrovascular disease (CVD), and coronary artery disease (CAD). The diagnosis was not affected by gender, BMI, smoking, and alcohol consumption. Hypertension was significantly correlated to the diagnosis of FH, as most of them were already hypertensive at diagnosis. It was noted that hypertension, diabetes, CVD, and CAD were seen at an earlier age among patients with definite FH. Conclusion: The prevalence of heterozygous FH at 12% among dyslipidemia patients and 1.3% among the general population was described for the first time in our region. This result should raise the awareness of our healthcare providers that FH, which is a major risk factor for premature CAD and CVD, exists, and early detection and management are important.

Genetically confirmed familial hypercholesterolemia in outpatients with hypercholesterolemia

Background Familial hypercholesterolemia （FH） is an autosomal dominant disorder of lipoprotein metabolism which can lead to premature coronary heart disease （pCHD）. There are about 3.8 million potential FH patients in China, whereas the clinical and genetic data of FH are limited. Methods Dutch Lipid Clinic Network （DLCN） criteria was used to diagnose FH in outpatients with hypercholesterolemia. Resequencing chip analysis combined with Sanger sequencing validation were used to identify mutations in the definite FH patients according to DLCN criteria. In silico analysis was conducted in mutations with previously unknown pathogenicity. Then, the novel mutant receptors were transfected into human embryo kidney 293 （HEK-293） cells. The binding and the internalization activities of the mu- tant receptors were analyzed by flow cytometry. Results The prevalence of definite FH in outpatients with hypercholesterolemia in this study is 3.2%. Using genetic testing, one homozygous FH （HoFH）, one heterozygous FH （HeFH） and three compound heterozygous FH patients were confirmed. Eight mutations in low-density lipoprotein receptor （LDLR） gene were identified, in which c.357delG was a novel mutation and co-segregated with the FH phenotype. Bioinformatic analysis confirmed that c.357delG was a pathogenic mutation. Furthermore, when compared with the wild-type LDLRs by flow eytometry analysis, the binding and internalization activities of c.357delG mutant LDLRs were reduced by 35% and 49%, respectively. Conclusions This study identified eight LDLR gene mutations in five patients with definite FH, in which c.357delG is a novel pathogenic mutation. These findings increase our understanding of the genetic spectrum of FH in China.

Two cases of familial hypercholesterolemia with premature acute coronary syndrome:Case report

Objective:To investigate the clinical characteristics of familial hypercholesterolemia and early-onset acute coronary syndrome(ACS),in order to improve the understanding and diagnosis and treatment of the disease.Methods:We retrospectively studied the clinical data of 2 patients with familial hypercholesterolemia and premature acute coronary syndrome treated in the Department of Cardiology,Tongji Hospital,Tongji Medical College,Huazhong University of Science and Technology.All patients underwent genetic testing and coronary artery angiography.Results:Two patients were heterozygous familial hypercholesterolemia by gene test.Coronary artery angiography showed that three coronary arteries had serious lesions,which recovered well after drug and surgical treatment.Conclusion:Patients with familial hypercholesterolemia were prone to early onset of acute coronary syndrome,which should be identified,diagnosed and treated as soon as possible.

A Pedigree Analysis of a Family With Familial Hypercholesterolemia

Objective The current study was designed to investigate the features of a family with familial hypercholesterolemia(FH). Methods Twenty members of three generations in a family with FH were enrolled in the study. The data collected were from clinical observation and subjected to pedigree analysis. Results The proband was a 41 years old male who suffered from angina pectoris with multi-vessel stenosis of coronary artery at the age of 40. Among 20 members, 8 individuals were demonstrated with hypercholes-terolemia in this family with the total incidence of 40% [54.5% (6/11) in male and 22. 2% (2/9) in femaleThe serum total cholesterol level was elevated in childhood from 7. 1 to 10. 8 mmol/L and tended to be raised with increasing age. In addition, the level of total cholesterol was found to be elevated both in a monozy-gote twin brothers and their offspring in the family. Conclusion FH appears to be a hereditary disease of autosomal dominance inheritance and the outcome of FH patients with coronary heart disease seems to be poor in prognosis.

Familial Hypercholesterolemia in an Azorean Family:A Novel Mutation in the Low-Density Lipoprotein Receptor Gene

Familial hypercholesterolemia (FH) is one of the most prevalent autosomal dominant inherited disorders. Mutations have been found in at least 3 genes: the low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), and proprotein convertase subtilisin/kexin type 9 (PCSK9). We report on an Azorean family with FH due to a novel mutation in the LDLR gene across three generations. The index-case was first seen at our endocrinology consultation at 12 years old, because of delayed growth and development. Laboratorial investigations revealed a complete failure of the anterior hypophysis due to a congenital malformation of the sella turcica. A total cholesterol of 313 mg/dL (90 - 190 mg/dL) and low-density lipoprotein cholesterol (LDL-C) of 262 mg/dL (<115 mg/dL) was found in routine blood tests. There was a paternal history of hypercholesterolemia, corneal arcus and myocardial infarction at an early age. Screening for mutations in LDLR gene was carried out. &#73n the affected cases, an intronic heterozygous point mutation (c.818-3C > G) causing a premature termination of transcription (stop codon) was identified.

Prevalence of familial hypercholesterolemia and its association with coronary artery disease:A Chinese cohort study

Background:Familial hypercholesterolemia(FH)is underrecognized,and its association with coronary artery disease(CAD)remains limited,especially in China.We aimed to investigate the prevalence of FH and its relationship with CAD in a large Chinese cohort.Methods:FH was defined using the Make Early Diagnosis to Prevent Early Death(MEDPED)criteria.The crude and age-sex standardized prevalence of FH were calculated based on surveys of the Prediction for Atherosclerotic Cardiovascular Disease Risk in China(China-PAR)project during 2007−2008.The associations of FH with incident CAD and its major subtypes were estimated with the cohort-stratified multivariate Cox proportional hazard models based on the data from the baseline to the last follow-up(2018−2020).Results:Among 98,885 included participants,190 participants were defined as FH.Crude and age−sex standardized prevalence and 95%confidence interval(CI)of FH were 0.19%(0.17%-0.22%)and 0.13%(0.10%-0.16%),respectively.The prevalence varied across age groups and peaked in the group of 60-<70 years(0.28%),and the peak prevalence(0.18%)in males was earlier,yet lower than the peak crude prevalence in females(0.41%).During a mean follow-up of 10.7 years,2493 cases of incident CAD were identified.After multivariate adjustment,FH patients had a 2.03-fold greater risk of developing CAD compared to non-FH participants.Conclusions:The prevalence of FH was estimated to be 0.19%in the participants,and it was associated with an elevated risk of incident CAD.Our study suggests that early screening of FH has certain public health significance for the prevention of CAD.

Functional analysis of low-density lipoprotein receptor in homozygous familial hypercholesterolemia patients with novel 1439 C →T mutation of low-density lipoprotein receptor gene

Background Familial hypercholesterolemia （FH）, caused by low density lipoprotein （LDL） receptor （LDL-R） gene mutations, is associated with increased risk of premature coronary heart disease. Until now, limited molecular data concerning FH are available in China. The present study described the clinical profiles and cell biological defects of a Chinese FH kindred with novel LDL-R gene mutation. Methods The patient＇s LDL-R gene coding region was sequenced. The patient＇s lymphocytes were isolated and the LDL-R expression, binding and up-take functions were observed by immunohistochemistry staining and flow cytometry detection. The patient＇s heart and the major large vessels were detected by vessel ultrasound examination and myocardial perfusion imaging （MPI）. Results The patient＇s LDL-R expression, LDL binding and up-take functions were significantly lower than normal control （39%, 63% and 76% respectively）. A novel homozygous 1439 C→T mutation of the LDL-R gene was detected in the patient and his family. ECG showed atypical angina pectoris. Echocardiogram showed stenosis of the coronary artery and calcification of the aortic valve and its root. Blood vessel ultrasound examination showed the thickness of large vessel intima, and the vessel lumen was narrowed by 71%. MPI showed ischemic changes. Conclusions The LDL-R synthesis dysfunction of FH patients leads to arterial stenosis and calcification, which are the major phenotype of the clinical disorder. The mutation of the LDL-R gene is determined. These data increase the mutational spectrum of FH in China.

Two novel mutations of the LDL receptor gene associated with familial hypercholesterolemia in a Chinese family

Background Familial hypercholesterolemia （FH） is a type of dominant autosomal disease that causes high levels of plasma low-density lipoprotein cholesterol （LDL-C）. In the past years, molecular data related to FH were limited in China. Now, to gain more information about FH, we analyzed one proband with a severe FH phenotype as well as his relatives. Methods After the entire coding sequence and the intron-exon junctions of the low-density lipoprotein receptor （LDLR） gene were amplified using PCR, we sequenced the LDLR gene of a Chinese FH family. RT-PCR was used to detect changes in the mRNA. Results Two novel mutations were identified in the LDLR gene of this family. One, W165X, was a G〉A substitution at the third nucleotide of codon 165. The other, IVS5-1G〉A, was also a G〉A substitution at the acceptor splice site of intron 5. The most striking discovery is that the proband was heterozygous for W165X but homozygous for IVS5-1G〉A. The cDNA sequencing showed that the IVS5-1G〉A mutation caused the insertion of 10 nucleotides, namely GCTCTCACAA, between exon 5 and exon 6. Conclusions The two nucleotide variations are thought to be the FH-causing mutations because the co-segregation of the mutant allele with the phenotype of FH has been shown in this Chinese family. These data show an increase in the mutational spectrum of FH in China and verify a scarce mutational form in the LDLR gene.

Analysis of low-density lipoprotein receptor gene mutations in a Chinese patient with clinically homozygous familial hypercholesterolemia

Objective To screen the point mutation of the low-density lipoprotein receptor (LDL-R) gene in Chinese familial hypercholesterolemia (FH) patients,characterize the relationship between the genotype and the phenotype and discuss the molecular pathological mechanism of FH. Methods A patient with clinical phenotype of homozygous FH and her parents were investigated for mutations in the promoter and all eighteen exons of the LDL-R gene. Screening was carried out using Touch-down PCR and direct DNA sequencing; multiple alignment analysis by DNASIS 2.5 was used to find base alteration,and the LDL-R gene mutation database was searched to identify the alteration. In addition,the apolipoprotein B gene (apo B) was screened for known mutations (R3500Q) that cause familial defective apo B 100 (FDB) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).Results Two new heterozygous mutations in exons 4 and 9 of the LDL-R gene were identified in the proband (C122Y and T383I) as well as her parents. Both of the mutations have not been published in the LDL-R gene mutation database. No mutation of apo B 100 (R3500Q) was observed. Conclusion Two new mutations (C112Y and T383I) were found in the LDL-R gene,which may result in FH and may be particularly pathogenetic genotypes in Chinese people.

A novel mutation in proprotein convertase subtilisin/kexin type 9 gene leads to familial hypercholesterolemia in a Chinese family

Background Familial hypercholesterolemia （FH） is an autosomal disorder associated with elevated plasma low density lipoprotein （LDL） levels leading to premature coronary heart disease （CHD）. As a result of long-term hyperlipemia, FH patients will present endarterium thickening and atherosclerosis. In the present study we scanned the related gene of a clinically diagnosed autosomal genetic hypercholesterolemia family for the possible mutations and established eukaryotic expression vector of mutation of proprotein convertase subtilisin/kexin type 9 （PCSK9） gene with gene recombination technique to investigate the contributions of the variation on low density lipoprotein receptor （LDL-R） metabolism and function alternation.Methods Mutation detection was conducted for LDL-R, apolipoprotein B100 （apoB100） and PCSK9 gene with nucleotide sequencing in a Chinese FH family. The full-length cDNA of wild type PCSK9 gene （WT-PCSK9） was obtained from Bel-7402. Site mutagenesis was used to establish the recombinant eukaryotic expression vector carrying pathogenic type of PCSK9 gene and the inserted fragment was sequenced. With the blank vector as control, liposome transfection method was used to transfect the Bel-7402 cells with recombinant plasmid. The expression of LDL-R mRNA was examined by RT-PCR. PCSK9 and the expression of LDL-R protein were determined by Western blotting. Results The G→T mutation at the 918 nucleotide of PCSK9 gene resulted in the substitution of the arginine by a serine at the codon 306 of exon 6. After sequencing, it was confirmed that the inserted fragment of established expression vector had correct size and sequence and the mutant was highly expressed in Bel-7402 cells. There was no significant variation in the levels of LDL-R mRNA. LDL-R mature protein was decreased by 57% after the cells were transfected by WT-PCSK9 plasmid. Mature LDL-R was significantly decreased by 12% after the cells were transfected by R306S mutant as evidenced by gray scale scanning, suggesting that the new mutant R306S can significantly decrease the expression of mature LDL-R protein.Conclusions A novel missense mutation of PCSK9 gene, R306S, was found and the eukaryotic expression vectors of mutant and wild-type of PCSK9 gene were established. There was no significant variation in the levels of LDL-R mRNA. The R306S mutation could significantly lead to the decrease of LDL-R mature protein expression, which might be the pathogenic gene of the FH family.

Proprotein convertase subtilisin/kexin type 9 inhibitor non responses in an adult with a history of coronary revascularization:A case report

BACKGROUND Familial hypercholesterolemia(FH)is an autosomal dominant disorder that is characterized by severely increased low-density lipoprotein(LDL)cholesterol levels.At the same time,elevated LDL levels accelerated the development of coronary heart disease.Several classes of drugs are currently in use to treat FH.Proprotein convertase subtilisin/kexin type 9 inhibitor(PCSK9i)is novel one of these.CASE SUMMARY This manuscript reports a case of FH that responded modestly after treatment with PCSK9i and statin drugs.Of even more concern is that the patient frequently admitted to the hospital during a 12-year follow-up period.Subsequently,we identified a heterozygous mutation,1448G>A(W483X)of the LDL receptor(LDLR)in this patient.The serum levels of PCSK9(proprotein convertase subtilisin/kexin type 9)in the patient was 71.30±26.66 ng/mL,which is close the average level reported in the literature.This LDLR mutation affects LDLR metabolism or structure,which may make it unsuitable for use of PCSK9i.CONCLUSION Our outcome demonstrates that LDLR-W483X represents a partial loss-of-function LDLR and may contribute to PCSK9i ineffective. In the meanwhile, additional measures aretherefore required (particularly with gene sequencing or change the treatment plan) must beinitiated as early as possible. Genetic testing for clinically challenging cases who do not respond toPCSK9i therapy is very helpful.