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

Screening and Evaluation of Gene Mutations in Familial Hypercholesterolemia Pedigrees in Guizhou Province

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。

Objective:To explore the results of gene mutation screening and evaluation in familial hypercholesterolemia(FH)families in Guizhou Province.Methods:According to the diagnostic criteria of the Dutch Lipid Diagnostic Network(DLCN)guidelines,a patient diagnosed with FH was selected from a tertiary hospital in Guiyang City from November 2021 to November 2022 for study.The pedigree was analyzed,and the total cholesterol(TC),triglyceride(TG),LDL-C,and high-density lipoprotein cholesterol(HDL-C)levels of family members were detected by C8000 automatic biochemical analyzer.The clinical data and DNA of the family were collected,and the pathogenic genes were sequenced by whole genome exon sequencing.The single nucleotide polymorphism(SNP)sites of four FH-related genes[low density lipoprotein receptor(LDLR),apolipoprotein B(ApoB),sibutramine 9a(PCSK9),LDLR adaptor protein 1(LDLRAP1)]were screened out,and the pathogenicity of SNP sites was analyzed by Polyphen-2 and SIFT software.The incidence of cardiovascular disease during dual filtration plasma exchange(DFPP)adsorption therapy and the changes in apolipoprotein A(ApoA),apolipoprotein E(ApoE),apolipoprotein B(ApoB),lipoprotein a(LPa),TC,TG,HDL-C,LDL-C,and free fatty acid(FFA)levels before and after treatment were also retrospectively analyzed.Results:The serum TC of I-1,II-1 and II-2 members of the family was 8.91 mmol/L,8.12 mmol/L and 7.98 mmol/L,respectively.I-1,II-1 and II-2 met the diagnostic criteria of FH.The scores of rs676210 and rs679899 in the ApoB gene of the family were 0.998 and 0.996,respectively,and the score of c.10094 A>T was 0.795.SIFT software predicted that the above three sites were harmful.The patient's condition was stable after DFPP treatment,and no serious cardiovascular events occurred.Compared with before adsorption treatment,the levels of ApoA,ApoE,ApoB,LPa,TG,HDL-C,LDL-C and TC after adsorption treatment were lower than those before adsorption treatment,and the levels of FFA were higher than those before adsorption treatment.The difference was statistically significant(P<0.05).Conclusion:Mutations in the two SNPs of the ApoB gene are likely to cause FH,and DFPP treatment is beneficial to regulate blood lipid levels in FH patients,thereby reducing the risk of cardiovascular disease.