摘要目的:通过分析不同等位基因分级的家族性高胆固醇血症（FH）患者前蛋白转化酶枯草溶菌素/kexin9型（PCSK9）抑制剂治疗前后低密度脂蛋白胆固醇（LDL-C）的变化，探讨FH表型分子病因分类对PCSK9抑制剂降脂疗效的提示作用。方法:选取2019年1月至2020年10月就诊于北京安贞医院的FH表型患者，收集其年龄、性别等临床信息，经二代测序技术进行致病基因检测。依据受累等位基因数量及基因受损程度将患者分为单等位基因-缺失突变组、单等位基因-缺陷突变组、多等位基因-缺失突变组、多等位基因-缺陷突变组以及无主要致病基因突变组。检测不同等位基因分级的患者干预前、4~6周的强化他汀治疗后、联合PCSK9抑制剂治疗1个月后的LDL-C水平和降幅，分析基线LDL-C水平与降幅的相关性以及各基因型分组治疗后LDL-C水平达到靶目标值的比例。结果:共纳入66例FH表型患者，其中男性47例（71.2%），女性19例（28.8%），年龄（43.1±13.4）岁。单等位基因-缺失突变组7例（10.6%），单等位基因-缺陷突变组25例（37.9%），多等位基因-缺失突变组8例（12.1%），多等位基因-缺陷突变组18例（27.3%），无主要致病突变组8例（12.1%）。PCSK9抑制剂联合治疗的LDL-C降幅由大到小依次是单等位基因组>无主要致病突变组>多等位基因组，整体分布于0~90%范围内，单等位基因2个分组和无主要致病基因组>50%>多等位基因2个分组。PCSK9抑制剂联合治疗下LDL-C进一步降幅由大到小依次为单等位基因组>无主要致病突变组>多等位基因组。总体FH表型患者中高强度他汀联合PCSK9抑制剂治疗后LDL-C降幅随基线LDL-C的水平升高而减小（ r=0.46， P<0.001），高强度他汀治疗基础上PCSK9抑制剂的进一步LDL-C降幅随基线LDL-C水平升高而减小（ r=0.40， P=0.001）。与其他组相比，单等位基因组高强度他汀联合PCSK9抑制剂治疗后LDL-C降幅较高且稳定，其中单等位基因-缺陷突变组LDL-C降幅随基线LDL-C水平升高而增大（ r=0.54， P=0.009），PCSK9抑制剂的进一步LDL-C降幅随基线LDL-C水平升高而减小（ r=0.43， P=0.040）。多等位基因组治疗前后LDL-C降幅因致病基因位点及组合方式不同而异。不同基因型FH表型患者LDL-C的达标率：为单等位基因组26例（86.7%）、无主要致病基因突变组6例（6/8）、多等位基因组1例（3.8%）。 结论:所有基因型患者均可以从他汀联合PCSK9抑制剂的强化降脂治疗中受益，不同分子病因的中国FH表型患者PCSK9抑制剂疗效存在显著差异，致病基因分析对FH患者PCSK9抑制剂降脂疗效具有提示作用。

abstractsObjective: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.