体外评估 LDLR c.2160delC 变异在家族性高胆固醇血症中的致病性。

In vitro assessment of the pathogenicity of the LDLR c.2160delC variant in familial hypercholesterolemia.

机构信息

Department of Cardiology, The First Affiliated Hospital of Ningbo University, Ningbo, Zhejiang, China.

Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.

出版信息

Lipids Health Dis. 2023 Jun 20;22(1):77. doi: 10.1186/s12944-023-01848-6.

DOI:10.1186/s12944-023-01848-6

PMID:37340302

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10280840/

Abstract

BACKGROUND

Familial hypercholesterolemia (FH) is an inherited disorder with markedly elevated low-density lipoprotein cholesterol (LDL-C) and premature atherosclerotic cardiovascular disease. Although many mutations have been reported in FH, only a few have been identified as pathogenic mutations. This study aimed to confirm the pathogenicity of the LDL receptor (LDLR) c.2160delC variant in FH.

METHODS

In this study, the proband and her family members were systematically investigated, and a pedigree map was drawn. High-throughput whole-exome sequencing was used to explore the variants in this family. Next, quantitative polymerase chain reaction (qPCR), western blot (WB) assays, and flow cytometry were conducted to detect the effect of the LDLR c.2160delC variant on its expression. The LDL uptake capacity and cell localization of LDLR variants were analyzed by confocal microscopy.

RESULTS

According to Dutch Lipid Clinic Network (DLCN) diagnostic criteria, three FH patients were identified with the LDLR c.2160delC variant in this family. An in-silico analysis suggested that the deletion mutation at the 2160 site of LDLR causes a termination mutation. The results of qPCR and WB verified that the LDLR c.2160delC variant led to early termination of LDLR gene transcription. Furthermore, the LDLR c.2160delC variant caused LDLR to accumulate in the endoplasmic reticulum, preventing it from reaching the cell surface and internalizing LDL.

CONCLUSIONS

The LDLR c.2160delC variant is a terminating mutation that plays a pathogenic role in FH.

摘要

背景

家族性高胆固醇血症（FH）是一种遗传性疾病，其特征为低密度脂蛋白胆固醇（LDL-C）显著升高和早发动脉粥样硬化性心血管疾病。尽管 FH 已报道了许多突变，但只有少数被确定为致病性突变。本研究旨在证实 LDL 受体（LDLR）c.2160delC 变异在 FH 中的致病性。

方法

本研究对先证者及其家系成员进行了系统的调查，并绘制了家系图谱。使用高通量全外显子组测序来探索该家系中的变异。接下来，进行了定量聚合酶链反应（qPCR）、western blot（WB）检测和流式细胞术，以检测 LDLR c.2160delC 变异对其表达的影响。通过共聚焦显微镜分析 LDLR 变体的 LDL 摄取能力和细胞定位。

结果

根据荷兰脂质诊所网络（DLCN）诊断标准，该家系中确定了 3 名 FH 患者携带 LDLR c.2160delC 变异。计算机分析表明，LDLR 2160 位点的缺失突变导致终止突变。qPCR 和 WB 的结果证实，LDLR c.2160delC 变异导致 LDLR 基因转录的早期终止。此外，LDLR c.2160delC 变异导致 LDLR 在内质网中积累，阻止其到达细胞表面并内化 LDL。