中国人群家族性高胆固醇血症LDLR基因突变研究进展

家族性高胆固醇血症(Familial hypercholesterolemia,FH)主要是由于低密度脂蛋白受体(Low-density lipoprotein receptor,LDLR)基因突变导致的单基因显性遗传性疾病。FH患者LDLR基因突变导致细胞膜表面LDLR减少或缺如,机体代谢胆固醇能力降低,血浆胆固醇增高并沉积在不同的组织和器官,常伴有全身黄色瘤和早发冠心病,因此FH也是最常见的严重代谢性疾病。世界范围内对LDLR基因突变的报道总共有1741种,经整理我国目前报道的140例FH指示病例,包括108种LDLR基因突变类型。文章对已报道的中国FH患者LDLR基因突变特点进行系统分析和综述,旨在为FH诊断治疗提供参考依据。     

家族性高胆固醇血症样表型遗传异质性的分子基础

家族性高胆固醇血症(FH)是由于低密度脂蛋白受体(LDL—R)基因突变,致使细胞表面LDL-R蛋白功能缺陷,导致血浆低密度脂蛋白(LDL)大幅度增高,并可导致早发冠心病。“FH”已经成为携带LDL-R基因突变患者的同意词,但日益增多的研究证实,其他6种基因突变也可通过不同机制导致FH样表型。这些致病基因的发现．促进胆固醇代谢的研究进入新领域,有助于深入探讨胆固醇代谢的调节机制,并将为FH样表型的诊断和治疗提供新的理论依据。文章就有关FH样表型遗传异质性的分子基础研究的近况作一简要综述．以引起人们的关注。     

家族性高胆固醇血症患者低密度脂蛋白受体基因复合杂合突变分析

目的:对1例临床确诊为纯合型家族性高胆固醇血症(FH)先证者及其核心家系成员进行基因检测分析,探讨患儿发病的分子病理基础.方法:收集先证者及父母血标本及临床资料,酚氯仿法提取基因组DNA,DNA直接测序方法检测低密度脂蛋白受体(LDL-R)基因18个外显子和启动子及载脂蛋白B(ApoB100)R3500Q位点,核苷酸序列分析结果与Gen Bank比对寻找突变.结果:(1)先证者三尖瓣轻度关闭不全,先证者父母双侧颈总动脉内-中膜增厚,先证者母亲左侧颈内动脉起始处后壁多发混合回声斑块(2)该家系排除ApoB100基因R3500Q突变;(3)先证者LDL-R基因第13外显子发生A606T和D601Y复合杂合突变,前者第1879位G→A碱基置换,导致丙氨酸改变为苏氨酸,后者为1864位G>T碱基置换,导致天冬氨酸改变为酪氨酸,其父为携带A606T突变的杂合子,其母为携带D601Y突变的杂合子.结论:先证者LDL-R基因存在A606T和D601Y复合杂合突变,它们分别来源于父系及母系遗传.     

家族性高胆固醇血症HDL-miRNAs调节血单核细胞功能机制

本研究通过生物信息学方法分析家族性高胆固醇血症患者外周血单核细胞差异表达基因、HDL载体差异表达miRNA及其生物学功能,研究差异HDL-miRNA与单核细胞差异基因的相关性,探讨HDL-miRNA调控外周血单核细胞功能机制,寻找动脉粥样硬化防治新靶点。运用R语言分析GEO数据库共享平台家族性高胆固醇血症外周血单核细胞基因及HDL-miRNA探针芯片得到差异基因及差异miRNA,利用miRwalk2. 0预测miRNA靶基因,并利用STRING进行蛋白互作分析,构建差异miRNA与差异基因之间的调控网络。运用GO及KEGG分析研究基因功能。利用GEO数据(GSE6054)筛选出834个差异表达基因,利用GEO数据(GSE25108)筛选出HDL上差异miRNA28个。交叉匹配得到由19个差异miRNA和56个差异基因组配对的74对miRNA-靶基因。GO富集分析56个差异基因主要富集于肾上腺素受体信号等分子功能。KEGG分析56个差异基因主要富集于造血谱系通路上。家族性高胆固醇血症差异HDL-miRNA与外周血单核细胞差异mRNA具有相关性,HDL-miRNA有通过调控血单核细胞功能的可能性,可能参与高胆固醇血症导致动脉粥样硬化过程。     

贵州省1例家族性高胆固醇血症家系基因突变筛查与评估

摘要 目的：探讨贵州省1例家族性高胆固醇血症（FH）家系基因突变筛查与评估结果。方法：参照荷兰脂质诊断网络（DLCN）指南诊断标准于2021年11月-2022年11月贵阳市某三甲医院选取1例临床诊断FH的患者进行研究,分析其家系系谱,采用C8000型全自动生化分析仪检测家系成员总胆固醇（TC）、甘油三酯（TG）、LDL-C、高密度脂蛋白胆固醇（HDL-C）水平;并采集家系临床相关数据,收集血清样本提取白细胞DNA进行全基因组外显子测序致病基因,筛选出4个FH相关基因[低密度脂蛋白受体（LDLR）、载脂蛋白B（ApoB）、西布曲明9a型（PCSK9）、LDLR衔接蛋白1（LDLRAP1）]的单核苷酸多态性（SNP）位点情况,采用Polyphen-2和SIFT软件对SNP位点进行致病性分析;同时回顾性分析双重滤过血浆置换(DFPP)吸附治疗期间的心血管疾病发生情况及治疗前后的载脂蛋白A（ApoA）、载脂蛋白E（ApoE）、载脂蛋白B（ApoB）、脂蛋白a（LPa）、TC、TG、HDL-C、LDL-C、游离脂肪酸（FFA）水平变化情况。结果：该家系Ⅰ-1成员血清LDL-C达8.16 mmol/L,Ⅱ-1成员血清LDL-C达7.0 mmol/L,Ⅱ-2成员血清LDL-C达3.45 mmol/L,按照DLCN标准,Ⅰ-1评7分,Ⅱ-1评6分,均提示患FH可能性大,达到FH临床诊断标准。利用Polyphen-2预测,该家系ApoB基因中rs676210、rs679899分别得分0.999、0.998,1个新位点c.10094A＞T得分为0.829,均提示可能致病,SIFT软件预测以上三个位点均有害。DFPP治疗后患者病情稳定,至今无心绞痛严重心血管事件发生。与吸附治疗前比较,吸附治疗后ApoA、ApoE、ApoB、LPa、TG、HDL-C、LDL-C、TC水平较低FFA水平较高,差异有统计学意义（P＜0.05）。结论：ApoB基因SNP位点突变很可能是该家系引起FH的主要原因,而DFPP治疗有利于调节FH患者血脂水平,进而降低心血管疾病的发生风险。     

家族性高胆固醇血症患者低密度脂蛋白受体基因新突变位点的鉴定

家族性高胆固醇血症(hypercholesterolemia familial,FH)是由于低密度脂蛋白受体(low density lipoprotein receptor,LDLR)基因突变导致的常染色体显性遗传性疾病,临床上表现为多发黄色瘤、高水平血浆LDL、早发性冠心病及有阳性家族史。本研究通过临床症状结合血脂测定诊断出一个FH家系,其纯合子FH患者的血浆总胆固醇水平高达19．05mmol／L,LDL达17．06mmol／L,并有黄色瘤;而杂合子FH患者的血浆总胆固醇水平为7．96mmol／L,LDL为5．55mmol/L,并有心绞痛症状和黄色瘤。我们对该FH家系患者LDLR基因的PCR扩增DNA片段进行测序,发现纯合子FH患者LDLR基因Exon4区域内发生了GAG683GCG突变,即编码LDLR第683位的谷氨酸被丙氨酸替换,而杂合子FH患者该位点呈现杂合突变。此基因型与临床诊断遗传谱完全一致。同时,利用获得Epstein-Barr(EB)病毒转化型人永生淋巴细胞株(EBV-Ls)与荧光探针DiI标记的LDL结合反应,再通过流式细胞仪检测结果显示,具有功能性LDLR的EBV-Ls细胞比例,在纯合子FH患者(7．02％)和杂合子FH患者(62．64％)均比健康对照者(84．69％)低,纯合子FH患者LDLR活性仅为健康对照者的8．29％、而杂合子FH患者LDLR活性约为健康对照者的73．96％,前者呈现非常显著的降低。这些EBV-Ls细胞LDLR的功能变化分析,有力地支持了该FH家系的临床诊断和DNA测序结果。经查阅最新的UMD-LDLR完全版证实,本研究发现鉴定的GAG683GCG突变是人LDLR基因的新突变位点。     

家族性高胆固醇血症低密度脂蛋白受体第13外显子突变分析

目的:探讨本课题组收集家族性高胆固醇血症(FH)患者中存在低密度脂蛋白受体(LDLR)第13外显子(E13)基因突变患者临床生化和心血管系统损害特点.方法:对9例临床诊断为FH、基因检测到LDLR基因E13突变的患者进行回顾性分析.结果:(1)临床诊断FH纯合子患者7名,其总胆固醇(TC)水平15.12～26.14 mmol/L,杂合子患者2名,TC水平11.30～11.75 mrnol/L.(2)均可见不同程度黄色瘤;(3)FH纯合子3例心电图出现ST-T改变;4例儿童和1例青年患者出现瓣膜损害,冠脉血流储备(CVFR)减低;杂合子心电图检查均正常,1例出现瓣膜损害,CVFR均正常.(4)核苷酸序列分析证实:9例E13突变患者中,A606T纯舍突变3名;D601Y纯合突变2名;A606T+、W462X和A606T+D601Y复合杂合突变各1名;A606T和D601Y杂合突变各1名.结论:FH严重损害患儿心血管系统和皮肤,LDLR基因E13出现的A606T和D601Y突变可能成为中国FH人群的高频突变位点.     

青少年家族性高胆固醇血症患者血浆同型半胱氨酸和高敏C 反应蛋白水 平的临床价值及与血脂相关性研究

目的:探讨血浆同型半胱氨酸(Homocysteine,Hcy)、高敏C反应蛋白(Hypersensitive C-reactive protein,hs-CRP)在家族性高胆固醇血症(FH)的纯合子和杂合子患者中的水平及其与临床生化指标的相关性。方法:入选在2013.10~2015.7期间在动脉硬化门诊随访、确诊的家族性高胆固醇患者34人(纯合子14例,杂合子20例)。根据FH纯合子、杂合子、健康体检者分成三组,分别测定其总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、空腹血糖(Glu)、Hcy、hs-CRP水平,并比较FH患者血浆LDL-C、非高密度脂蛋白(non-HDL)水平Hcy、hs-CRP水平的相关性。结果:FH组的TC、LDL-C、non-HDL、Hcy水平显著高于正常对照组(P0.05)。FH根据基因型亚组分析中,青少年纯合子组HDL-C[(0.78±0.21)vs(1.25±0.40)mmol/L]小于杂合子组(P0.001),而TC[(16.11±2.66)vs(7.30±2.54)mmol/L]、LDL-C[(14.06±2.22)vs(5.25±2.16)mmol/L]、non-HDL[(15.33±2.60)vs(6.05±2.61)mmol/L]、Hcy[(19.3±11.58)vs(11.29±3.42)μmol/L]水平显著高于杂合子组(P0.05)。Pearson相关性分析显示,FH患者血浆LDL-C、non-HDL水平与Hcy水平呈正相关(P0.05),而与hs-CRP无相关性。结论:FH患者,特别是青少年的纯合子患者,与对照组相较,具有较高的TC、LDL-C和Hcy水平,并且与血浆LDL-C、non-HDL水平呈正相关。FH患者hs-CRP的水平高于健康人,但差异无统计学意义,与血浆LDL-C、non-HDL水平也无明显相关性。     

膳食干预对高胆固醇血症患者血脂和营养状况的影响

目的：探讨个体化膳食干预对高胆固醇血症患者血脂指标和营养状况的影响。方法：选取2013年6月—2014年12月收入北京友谊医院且诊断为高胆固醇血症的90例患者,膳食干预3个月,使用24 h膳食回顾调查法和食物频度法,分析调查对象每天膳食中热能及各种营养素的摄入量,与中国居民膳食推荐摄入量比较,分析膳食干预前后患者的饮食情况、血脂指标和相关营养指标的变化。结果：与每人每日各类食物适宜摄入量相比,高胆固醇血症患者在膳食干预前,蔬菜、水果、豆类食物的摄入量偏少,肉类、蛋、奶、油脂类食物摄入量偏高,营养素供能比例不适宜,蛋白质和脂肪供能比例偏高,碳水化合物供能比例偏低;与膳食干预前相比,膳食干预后每日谷类食物、肉类、鸡蛋、奶、油脂类的摄入量显著降低,蔬菜、水果、豆类的摄入量显著增加,摄入的总能量显著降低,摄入的蛋白质、脂肪的量及其供能比显著降低,动物蛋白的供能比显著降低,碳水化合物的摄入量及其供能比显著增加）;经过膳食干预后,高胆固醇血症患者的血清总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）水平显著降低,血清高密度脂蛋白胆固醇（HDL-C）水平显著増高,患者的体质指数（BMI）显著降低,血清总蛋白（TP）、白蛋白（ALB）、血红蛋白（HGB）与膳食干预前相比差异无统计学意义。结论：高胆固醇血症患者通过改善膳食结构和降低体质指数,可以降低TC、TG、LDL-C等血脂指标,升高HDL-C,其营养状况不会受到影响。     

Familial hypercholesterolemia in children

PURPOSE OF THIS REVIEW: This review provides an update on recent advances in the diagnosis and management of children with familial hypercholesterolemia. RECENT FINDINGS: A large cross-sectional cohort study of paediatric familial hypercholesterolemia demonstrated that affected children had a 5-fold more rapid increase of carotid arterial wall intima-media thickness during childhood years than their affected siblings. This faster progression led to a significant deviation in terms of intima-media thickness from the age of 12 years and onwards. Low-density lipoprotein cholesterol was a strong and independent predictor of carotid artery intima-media thickness in these children, which confirms the pivotal role of low-density lipoprotein cholesterol for the development of atherosclerosis. In this condition lipid lowering by statin therapy is accompanied by carotid intima-media thickness regression in familial-hypercholesterolemic children, which suggests that initiation of low-density lipoprotein cholesterol-reducing medication in childhood already can inhibit or possibly reduce the faster progression of atherosclerosis. Furthermore, these trials demonstrated that statins are safe and do not impair growth or sexual development in these children. Conversely, products containing plant sterols reduced low-density lipoprotein cholesterol levels by 14%, but did not improve endothelial dysfunction as assessed by flow-mediated dilatation. SUMMARY: Children with familial hypercholesterolemia clearly benefit from lipid-lowering strategies. Statins are safe agents and have been proven to reduce elevated low-density lipoprotein cholesterol levels significantly. In addition, statins improve surrogate markers for atherosclerosis. Therefore these agents should become the pivotal therapy in children with familial hypercholesterolemia.     

Familial hypercholesterolemia in South African Afrikaners

Summary Familial hypercholesterolemia (FH), at a prevalence of more than 1 in 100, is at least five times more common in one South African population group than in populations in North America and Europe. Fourteen homozygotic tamilial hypercholesterolemic subjects from this South African group were genotyped for two intragenic DNA restriction fragment length polymorphisms (RFLPs) in the LDL-receptor gene. A Stu I polymorphism is located in exon 8, and a Pvu II polymorphism, in intron 15. Of ten unrelated FH homozygotes genotyped for both RFLPs, nine were homozygous for an S+P- haplotype, and one was heterozygous for an S+P-/S-P+ heplotype. The remaining four were genotyped for Pvu II only and were homozygous for P-. Compared with a previously determined population frequency for the latter, this represents an association (P<0.05) between the frequency for the P- allele and FH in this population, and this finding is consistent with the founder gene effect previously postulated to be present on genealogical and biochemical evidence.     

Familial defective apolipoprotein B-100: a mutation of apolipoprotein B that causes hypercholesterolemia

Familial defective apolipoprotein B-100 is a genetic disorder of apolipoprotein B-100 that causes moderate to severe hypercholesterolemia. A single amino acid mutation in apolipoprotein B diminishes the ability of low density lipoproteins to bind to the low density lipoprotein receptor. Low density lipoproteins accumulate in the plasma because their efficient receptor-mediated catabolism is disrupted. This mutation has been identified in the United States, Canada, and Europe and is estimated to occur at a frequency of approximately 1/500 in these populations. Thus, it appears that this newly described disorder may be a significant genetic cause of hypercholesterolemia in Western societies.     

A relaxation technique in the management of hypercholesterolemia.

Chronic sympathetic nervous system overactivity has been implicated as a factor capable of elevating and maintaining high serum cholesterol levels independent of dietary measures. We conducted a controlled trial to determine the effect of a relaxation technique. Transcendental Meditation, on serum cholesterol levels in hypercholesterolemic subjects. Serum cholesterol levels were measured at beginning and end of an 11-month period in 12 hypercholesterolemic subjects who regularly practiced meditation. Eleven hypercholesterolemic controls who did not practice the technique were similarly followed up for 13 months. Paired comparisons showed a significant (p less than 0.005) reduction in fasting serum cholesterol levels of those subjects who practiced meditation. These results suggest that the regular practice of a relaxation technique may contribute, most likely through a reduction in adrenergic activity, to the amelioration of hypercholesterolemia in certain subjects.     

Familial hypercholesterolemia in St. Petersburg: Diversity of mutations argues against a strong founder effect

Examination of low-density lipoprotein (LDL) receptor gene, its promoter, and most of exon-intron boundaries from 74 probands with familial hypercholesterolemia (FH) of St. Petersburg revealed 34 mutations and 8 widely spread polymorphisms at this locus. Only four mutations were considered neutral, while the other 30 are likely to cause familial hypercholesterolemia (FH). Mutations in the LDL receptor gene, causing the disease, were identified in 41 (55%) out of 74 families with FH. Mutation R3500Q in apolipoprotein B (APOB) gene was not detected in all probands. Therefore in the families lacking mutations hypercholesterolemia was caused by mutations in the introns of the LDL receptor gene or by other genetic factors. Nineteen mutations causing disease progression were described in St. Petersburg for the first time, while 18 of them are specific for Russia. Among Ashkenazi Jews, predominant mutation G197del was detected in 30% (7 out of 22) of patients with FH. In the Slavic population of St. Petersburg, no predominant mutations were detected. Only five mutations were identified in two Slavic families, while 24 were found in unique families. These data are indicative of the lack of a strong founder effect for FH in the St. Petersburg population.     

Familial hypercholesterolemia in St. Petersburg: diversity of mutations argues against a strong founder effect

Examination of low-density lipoprotein (LDL) receptor, its promoter, and major exon-intron boundaries from a sample of patients with familial hypercholesterolemia (FH) from 74 probands of St. Petersburg revealed 34 mutations and 8 widely spread polymorphisms at this locus. Only four mutations were considered silent, while the other 30 are likely associated with familial hypercholesterolemia (FH). Mutations in the LDL receptor gene, inducing the disease, were identified in 41 (55%) out of 74 families with FH. Mutation R3500Q in apolipoprotein B (APOB) gene was not detected in all probands. Therefore in the families lacking mutations hypercholesterolemia was induced by mutations in the introns of the LDL receptor gene or by other genetic factors. Nineteen mutations causing disease progression were described in St. Petersburg for the first time, while 18 of them are specific for Russia. Among Ashkenazi Jews, major mutation G197del was detected in 30% (7 out of 22) of patients with FH. In the Slavic population of St. Petersburg, no major mutations were detected. Only five mutations were identified in two families, while 24 were found in isolated families. These data are indicative of the lack of a strong founder effect for FH in the St. Petersburg population.