1.Analysis of clinical phenotypes and variants of LDLR gene in two Chinese patients with familial hypercholesterolemia.
Kexin WANG ; Tao SUN ; Xiaoping ZHANG ; Yahui ZHANG ; Hai GAO ; Yanlong REN ; Xiaoyan LI
Chinese Journal of Medical Genetics 2022;39(12):1344-1348
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
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China
;
Hyperlipoproteinemia Type II/genetics*
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Phenotype
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Receptors, LDL/genetics*
2.Genetic analysis of a patient with familial hypercholesterolemia due to variant of LDLR gene.
Guanxiong WANG ; Liting LIU ; Yang GAO ; Mingrong LYU ; Huan WU ; Xiaojin HE
Chinese Journal of Medical Genetics 2023;40(4):458-461
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
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Cholesterol, LDL/genetics*
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Heterozygote
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Hyperlipoproteinemia Type II/genetics*
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Mutation
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Pedigree
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Phenotype
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Receptors, LDL/genetics*
3.Functional analysis of low-density lipoprotein receptor in homozygous familial hypercholesterolemia patients with novel 1439 C-->T mutation of low-density lipoprotein receptor gene.
Jie LIN ; Lu-ya WANG ; Shu LIU ; Jun-hui XIA ; Qiang YONG ; Lan-ping DU ; Xiao-dong PAN ; Hong XUE ; Bao-sheng CHEN ; Zhi-sheng JIANG
Chinese Medical Journal 2008;121(9):776-781
BACKGROUNDFamilial 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.
METHODSThe 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).
RESULTSThe 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.
CONCLUSIONSThe 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.
Adult ; Child, Preschool ; Homozygote ; Humans ; Hyperlipoproteinemia Type II ; genetics ; Middle Aged ; Mutation ; Receptors, LDL ; genetics ; physiology
4.Screening of LDLR gene mutations in nine patients with familial hypercholesterolemia.
Xiaolu MENG ; Nuo SI ; Yuqi SHEN ; Qi WANG ; Jiangchun HE ; Chaoxiao LU ; Wei WU ; Shuyang ZHANG ; Xue ZHANG
Chinese Journal of Medical Genetics 2018;35(6):783-786
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
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Genetic Testing
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Humans
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Hyperlipoproteinemia Type II
;
genetics
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Mutation
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Phenotype
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Receptors, LDL
;
genetics
6.Clinical analysis of 4 children with hereditary hypercholesterolemia.
Hui Min HAO ; Ya Nan GUO ; Dong Xia FU ; Bing Yan CAO ; Hai Yan WEI
Chinese Journal of Pediatrics 2022;60(12):1327-1331
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
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Humans
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Hypercholesterolemia/genetics*
;
Retrospective Studies
;
Hyperlipoproteinemia Type II/genetics*
;
Cholesterol, LDL
7.Identification and 3D architecture analysis of the LIPC gene mutation in a pedigree with familial hypercholesterolemia-like phenotype.
Hang ZHANG ; Fang Yuan LI ; Yu HAO ; Xu Min WANG ; Ju ZHANG ; Ya Luan MA ; Hui ZENG ; Jie LIN
Chinese Journal of Cardiology 2023;51(7):716-721
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
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Male
;
Hyperlipoproteinemia Type II/genetics*
;
Lipase/genetics*
;
Lipids
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Mutation
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Pedigree
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Phenotype
;
Proteins
8.Screening, Diagnosis, and Treatment of Familial Hypercholesterolemia: Symposium of the Education Committee, Korean Society of Lipid and Atherosclerosis.
Chan Joo LEE ; Ji Hyun LEE ; Seonghoon CHOI ; Shin Hye KIM ; Hyun Jae KANG ; Sang Hak LEE ; Kyong Soo PARK
Journal of Lipid and Atherosclerosis 2018;7(2):122-154
Familial hypercholesterolemia (FH) is typically associated with single gene mutation that is inherited by autosomal dominant manner. Due to high cardiovascular risk, aggressive discovery, diagnosis, and treatment of FH are critical. Although FH is being increasingly spotlighted, we do not have sufficient data on Korean patients with FH. Here, we present the content of symposium of the Education Committee, Korean Society of Lipid and Atherosclerosis held in May 2018: 1) epidemiology, clinical diagnosis, Korean FH data, and regulation in Korea; 2) genes associated with FH, sequencing process in suspicious proband, cascade screening, and difficulty in genetic diagnosis in FH; 3) the importance of lipid-lowering therapy in FH, conventional and novel therapeutics for FH; 4) diagnosis of FH in children and adolescence, screening, and treatment of FH in children and adolescence; 5) history of FH studies in Korea, the structure and current status of FH registry of Korean Society of Lipid and Atherosclerosis; and 6) difficulty in diagnosis of heterozygous and homozygous FH, drug intolerance and achievement of treatment target. Discussion between speakers and panels were also added. We hope that this article is helpful for understanding FH and future studies performed in Korea.
Adolescent
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Atherosclerosis*
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Child
;
Diagnosis*
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Education*
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Epidemiology
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Genetics
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Hope
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Humans
;
Hyperlipoproteinemia Type II*
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Korea
;
Mass Screening*