OBJECTIVE: To investigate the gene detection results of 2 patients with familial hypercholesterolemia (FH) caused by complex heterozygous variation, and to clarify the relationship between clinical manifestations and gene variation. METHODS: Two patients (patient 1 and 2) with FH who visited Beijing Anzhen Hospital Affiliated to Capital Medical University in 2018 were selected as research subjects. A retrospective study method was used to collect clinical and family history data of the two patients. And 2 mL of peripheral venous blood from each of the two patients was collected, and genomic DNA extraction was performed on the blood samples. Sanger sequencing was used to validate the variant sites of the two patients detected by whole-exome sequencing (WES). Pathogenicity of variants was classified based on the American College of Medical Genetics and Genomics (ACMG) Standards and Guidelines for the Classification of Genetic Variants (hereinafter referred to as the "ACMG Guidelines"), and the impact of variant was analyzed using multiple bioinformatics tools including SIFT, PolyPhen-2, and SWISS-MODEL. This study has been approved by Beijing Anzhen Hospital Affiliated to Capital Medical University (Ethics No. 2024215X). RESULTS: Patient 1 initially presented with early-onset coronary heart disease, with initial lipid levels of serum total cholesterol (TC) 9.86 mmol/L (normal reference value: 3.10~5.20 mmol/L) and serum low-density lipoprotein cholesterol (LDL-C) 8.37 mmol/L (normal reference value: 1.27~3.12 mmol/L) on admission. Patient 1 initially underwent treatment with rosuvastatin combined with ezetimibe for one month, but the lipid-lowering effect was not significant. The lipid-lowering therapy was then adjusted to atorvastatin combined with ezetimibe and probucol. After one year of treatment, the patient developed paroxysmal chest pain symptoms. A follow-up lipid profile showed a serum TC level of 4.50 mmol/L and a LDL-C level of 3.55 mmol/L. The lipid-lowering regimen was continued, and the serum LDL-C levels were maintained between 2.65 and 3.66 mmol/L. Patient 2 was found to have an abnormally high blood lipid level and carotid artery hardening during physical examination, with an initial blood lipid level of serum TC 11.82 mmol/L and serum LDL-C 9.63 mmol/L. After receiving rosuvastatain therapy, the lipid-lowering effect was significant. WES revealed that patient 1 carried the heterozygous variants c.1871_1873del(p.Ile624del) and c.1747C>T (p.His583Tyr) in the LDLR gene (NM_000527.4), while patient 2 carried the heterozygous variants c.1747C>T (p.His583Tyr) in the LDLR gene and c.6936_6937inv (p.Ile2313Val) in the APOB gene (NM_000384). According to the ACMG Guidelines, the LDLR gene c.1747C>T (p.His583Tyr) was classified as a pathogenic variant (PS3+PM1+PM2_supporting+PM5+PP2+PP3), and c.1871_1873del (p.Ile624del) was classified as a pathogenic variant (PS3+PS4+PM2_supporting+PM1+PM4); the APOB gene c.6936_6937inv (p.Ile2313Val) was classified as a variant of uncertain clinical significance (PM2_supporting BP4). CONCLUSION Patients 1 and 2 in this study were patients with complex heterozygous variant FH, and their genotypic differences may be related to the differences in clinical serum LDL-C levels and the efficacy of hypolipidemic agents.
Humans ; Hyperlipoproteinemia Type II/drug therapy* ; Male ; Female ; Heterozygote ; Adult ; Middle Aged ; Receptors, LDL/genetics* ; Retrospective Studies ; Mutation ; Exome Sequencing

Objective: To identify and analyze 3D architecture of the mutational sites of susceptible genes in a pedigree with familial hypercholesterolemia-like phenotype (FHLP). Methods: This is a case series study. A pedigree with suspected familial hypercholesterolemia was surveyed. The proband admitted in Beijing Anzhen Hospital in April 2019. Whole-exome sequencing was performed to determine the mutational sites of susceptible genes in the proband. Polymerase chain reaction (PCR) sequencing was used to verify the pathogenic variant on proband's relatives. The structural and functional changes of the proteins were analyzed and predicted by Discovery Studio 4.0 and PyMol 2.0. Results: The patients in the pedigree showed abnormal lipid profiles, especially elevated levels of total cholesterol(TC). The genetic screening detected the c.1330C>T SNP in the exon 8 of lipase C (LIPC) gene, this mutation leads to an amino acid substitution from arginine to cysteine at position 444 (Arg444Cys), in the proband and proband's father and brother. In this family, members with this mutation exhibited elevated TC, whereas lipid profile was normal from the proband's mother without this mutation. This finding indicated that LIPC: c.1330C>T mutation might be the mutational sites of susceptible genes. The analysis showed that Arg444Cys predominantly affected the ligand-binding property of the protein, but had a limited impact on catalytic function. Conclusion: LIPC: c.1330C>T is a new mutational site of susceptible genes in this FHLP pedigree.
Humans ; Male ; Hyperlipoproteinemia Type II/genetics* ; Lipase/genetics* ; Lipids ; Mutation ; Pedigree ; Phenotype ; Proteins

OBJECTIVE: To analyze variant of LDLR gene in a patient with familial hypercholesterolemia (FH) in order to provide a basis for the clinical diagnosis and genetic counseling. METHODS: A patient who had visited the Reproductive Medicine Center of the First Affiliated Hospital of Anhui Medical University in June 2020 was selected as the study subject. Clinical data of the patient was collected. Whole exome sequencing (WES) was applied to the patient. Candidate variant was verified by Sanger sequencing. Conservation of the variant site was analyzed by searching the UCSC database. RESULTS: The total cholesterol level of the patient was increased, especially low density lipoprotein cholesterol. A heterozygous c.2344A>T (p.Lys782*) variant was detected in the LDLR gene. Sanger sequencing confirmed that the variant was inherited from the father. CONCLUSION The heterozygous c.2344A>T (p.Lys782*) variant of the LDLR gene probably underlay the FH in this patient. Above finding has provided a basis for genetic counseling and prenatal diagnosis for this family.
Humans ; Cholesterol, LDL/genetics* ; Heterozygote ; Hyperlipoproteinemia Type II/genetics* ; Mutation ; Pedigree ; Phenotype ; Receptors, LDL/genetics*

OBJECTIVE: To explore the correlation between clinical phenotypes and pathogenic variants in two patients with familial hypercholesterolemia. METHODS: Both patients were subjected to whole exome sequencing (WES) with a focus on the analysis of genes associated with dyslipidemia. Candidate variants were verified by Sanger sequencing of the patients and their family members. RESULTS: WES revealed that the proband 1 has harbored two heterozygous variants of the LDLR gene, namely c.1360G>A (p.D454N) and c.292G>A (p.G98S), whilst proband 2 has harbored a heterozygous c.321T>G (p.C107W) variant of the LDLR gene. Based on the guidelines from the American College of Medical Genetic and Genomics (ACMG), the above variants were respectively predicted to be likely pathogenic (PM1+PM2+PP2+PP3+PP4+PP5), variant of unknown significance (PM1+PP2+PP3), and likely pathogenic (PM1+PM2+PP2+PP4+PP5). Treatment with PCSK9 inhibitor has attained a significant effect in proband 1 but no apparent effect in proband 2. CONCLUSION Variants of the LDLR gene probably underlay the familial hypercholesterolemia in the two pedigrees. The difference in the severity of the clinical phenotypes and response to PCSK9 inhibitor treatment between the two probands may be attributed to the different genotypes of the LDLR gene. Genetic testing not only can provide a basis for clinical diagnosis, but also facilitate the choice of lipid-lowering drugs.
Humans ; China ; Hyperlipoproteinemia Type II/genetics* ; Phenotype ; Receptors, LDL/genetics*

Genetic Testing ; Humans ; Hyperlipoproteinemia Type II/genetics* ; Pedigree ; Receptors, LDL/genetics*

Antiviral Agents ; Cholesterol, LDL ; Humans ; Hyperlipoproteinemia Type II ; Proprotein Convertase 9/genetics*

Objective: To investigate the clinical characteristics of hereditary hypercholesterolemia in childhood. Methods: The clinical data including general conditions, clinical manifestations, laboratory tests, and genetic testing results of 4 children with hereditary hypercholesterolemia who admitted to Henan Children's Hospital from January 2020 to December 2020 were retrospectively analyzed. Results: There were 4 female children aged 5.5,1.5,6.3,3.1 years, all presented with skin xanthoxoma as the chief complaint. Plasma total cholesterol (range 11.8 to 20.9 mmol/L) and low density lipoprotein-cholesterol (range 8.2 to 13.7 mmol/L) were significantly elevated. The serum β-glutamate levels in case 1 (241.2 μmol/L) and case 2 (164.2 μmol/L) increased significantly. Genetic analysis revealed compound heterozygous variants of ABCG8 gene in case 1 and ABCG5 gene in case 2 who were diagnosed with sitosterolemia. Case 3 and 4 who all had family history of hypercholesterolemia and compound heterozygous variants of LDLR gene were diagnosed with familial hypercholesterolemia. After diet treatment, the blood lipids returned normal and the skin xanoma subsided in case 1 and 2. In case 3 and 4, the blood lipids gradually decreased after diet and rosuvastatin treatment. Conclusions: Xanthomatosis is the common clinical manifestation of sitosterolemia and familial hypercholesterolemia. Family history, blood plant sterol profile, genetic variation, and changes in blood lipids after early dietary treatment are helpful for disease identification.
Child ; Humans ; Hypercholesterolemia/genetics* ; Retrospective Studies ; Hyperlipoproteinemia Type II/genetics* ; Cholesterol, LDL

Objective: This study intends to explore the difference in the efficacy of PCSK9 inhibitors in patients with different FH phenotypes by analyzing the level of blood lipids before and after treatment with PCSK9 inhibitors in patients with familial hypercholesterolemia (FH) with different allele grades. Methods: Patients with FH phenotype, who admitted to Beijing Anzhen Hospital from January 2019 to October 2020, were enrolled. Age, sex and other clinical information were collected from enrolled, and the pathogenic genes were detected by the second generation sequencing technique. The patients were divided into five groups according to the number of alleles involved and the degree of gene damage: single allele-null mutation group, single allele-defect mutation group, multi-allele-null mutation group, multi-allele-defect mutation group and no major pathogenic gene mutation group. The results of blood lipids were collected before medication, 4-6 weeks of intensive statin treatment and one month after combined treatment with PCSK9 inhibitor (PCSK9i). The LDL-C level were compared among groups. ASCVD risk stratification was performed in all patients, and the proportion of LDL-C level reaching the corresponding risk stratification target value of each genotype group after treatment was analyzed. Results: A total of 66 patients with FH phenotype were included, including 47 males (71.2%) and 19 females (28.8%),the mean age was(43.1±13.4 years). There were 7 cases in single allele-null mutation group (10.6%), 25 cases in single allele-defect mutation group (37.9%), 8 cases in multi-allele-null mutation group (12.1%), 18 cases in multi-allele-defect mutation group (27.3%) and 8 cases in no major pathogenic mutation group (12.1%). The degree of LDL-C reduction post combined PCSK9 inhibitor therapy was as follows: single allele mutation group>no major pathogenic mutation group>multi-allele mutation group, general distribution was in the range of 0-90.0%. Two groups of single allele mutation and no major pathogenic mutation group>50.0%>multi-allele mutation group. Under the combined treatment of PCSK9 inhibitors, the further decrease of LDL-C was in the order of single allele mutation group>non-major pathogenic mutant group>multi-allele mutation group. The efficacy of combined therapy on reducing LDL-C at 1 month after treatment decreased with the increase of baseline LDL-C level (r = 0.46, P<0.001) in patients with FH phenotype. In addition, the further decrease of LDL-C level post high-intensity statin therapy combined with PCSK9 inhibitors decreased with the increase of baseline LDL-C levels (r = 0.40, P<0.001). The degree of LDL-C decrease was high and stable by statin combined with PCSK9 inhibitor therapy in single allele mutation group. In the single allele-defect mutant group, the decrease of LDL-C increased with the increase of baseline LDL-C level post intensive statin treatment and combined PCSK9 inhibitor treatment ((r=0.54, P=0.009); r=0.45,P=0.030), and the further decrease of LDL-C level decreased with the increase of baseline LDL-C level in single allele-defect mutant group post combined therapy with PCSK9 inhibitor (r=0.43, P=0.040). The decrease of LDL-C in patients with the multi-allele mutation group varied with different pathogenic gene loci and combinations post combined therapy with PCSK9 inhibitor. There was no significant difference in the level of blood lipids between the group without major pathogenic gene mutation and the group with single allele mutation before and after treatment. The percentage of patients achieving LDL-C goals with different genotypes of phenotypic FH were as follows: single allele mutation group (86.7%), non-major pathogenic mutant group (75.0%) and multi-allele mutation grou (<5.0%). Conclusions: All patients with different FH phenotypes could benefit from the intensive lipid-lowering therapy with statins and PCSK9 inhibitors, however, there are significant differences in the efficacy of lowering LDL-C in Chinese patients with FH phenotype with different molecular etiologies. Therefore, the pathogenic gene analysis may suggest the lipid-lowering effect of PCSK9 inhibitors in patients with FH.
Adult ; Female ; Genotype ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Hyperlipoproteinemia Type II/genetics* ; Male ; Middle Aged ; Proprotein Convertase 9/genetics*

Child ; DNA Copy Number Variations/genetics* ; High-Throughput Nucleotide Sequencing ; Humans ; Hyperlipoproteinemia Type II/genetics* ; Multiplex Polymerase Chain Reaction

OBJECTIVE: To screen for LDLR gene mutations in 9 patients with familial hypercholesterolemia (FH). METHODS: All exons of the LDLR gene and flanking intronic sequences were amplified by PCR and subjected to automatic DNA sequencing. For patients with homozygous or compound heterozygous mutations, parental DNA sequencing or T cloning sequencing was carried out to determine the parental origin of the mutant alleles. RESULTS: Direct sequencing of PCR products revealed 8 LDLR variants in 7 patients, which included c.259T>G, c.513delC, c.530C>T, c.682G>T, c.763C>T, c.1187-10G>A, c.1948delG, and c.1730G>A, among which c.1948delG was novel. Four patients have carried heterozygous mutations, two carried homozygous mutations, and one carried compound heterozygous mutations. The patients with biallelic mutations presented with a more severe phenotype compared those carrying heterozygous mutations. CONCLUSION LDLR mutations were identified in 7 out of 9 patients with FH. Among the 8 identified LDLR mutations, c.1948delG was firstly reported. Above findings have expanded the mutation spectrum of LDLR gene.
DNA Mutational Analysis ; Genetic Testing ; Humans ; Hyperlipoproteinemia Type II ; genetics ; Mutation ; Phenotype ; Receptors, LDL ; genetics