2个遗传性凝血因子Ⅺ缺陷症家系的表型与基因型分析  

Phenotype and Genotype Analysis in Two Pedigrees with Hereditary Coagulation Factor Ⅺ Deficiency

作　　者：翁妙珊 林芬 章金灿 吴教仁 余雪梅 杨立业 WENG Miao-shan;LIN Fen;ZHANG Jin-can;WU Jiao-ren;YU Xue-mei;YANG Li-ye(Clinical Laboratory,Chaozhou Central Hospital Affiliated to Southern Medical University,Chaozhou 521000,China;Central Laboratory,Chaozhou Central Hospital Affiliated to Southern Medical University,Chaozhou 521000,China;Digestive Department,Chaozhou Central Hospital Affiliated to Southern Medical University,Chaozhou 521000,China)

机构地区：[1]南方医科大学附属潮州中心医院检验科,潮州521000 [2]南方医科大学附属潮州中心医院中心实验室,潮州521000 [3]南方医科大学附属潮州中心医院消化二科,潮州521000

出　　处：《四川大学学报（医学版）》2020年第2期252-256,共5页Journal of Sichuan University(Medical Sciences)

基　　金：潮州市卫生健康局科研项目(No.2019042);潮州市科技计划项目(No.2019ZC18)资助。

摘　　要：目的对2个遗传性凝血因子Ⅺ(FⅪ)缺陷症家系进行表型诊断和基因突变分析,探讨其分子发病机制。方法对2014年11月及2018年1月潮州中心医院收治的2例遗传性凝血因子FⅪ缺陷症患者及家系进行分析。采用血浆凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、FⅪ活性(FⅪ∶C)和FⅪ抗原(FⅪ∶Ag)等凝血指标进行表型诊断;对2个先证者FⅪ基因所有的外显子及其侧翼序列进行扩增,PCR产物纯化后直接测序,检测其基因突变。针对先证者的突变位点,分别对其家系成员进行相应的基因突变检测。应用逆转录PCR (RT-PCR)检测先证者-1 FⅪmRNA的水平,分析突变对FⅪmRNA剪切造成的影响。结果先证者-1男性,7岁。PT为10.7 s,APTT为97.4 s(参考值9~12.8 s和24~40 s),FⅪ∶C为0.6%,FⅪ∶Ag<1%(参考值65%~150%和72.1%~122.3%);先证者-2女性,30岁。PT为11.7 s,APTT为71.3 s,FⅪ∶C为0.7%,FⅪ∶Ag<1%。2例先证者因子Ⅷ活性(FⅧ∶C)、因子Ⅸ活性(FⅨ∶C)和因子Ⅻ活性(FⅫ∶C)均在正常范围内。先证者-1基因测序发现FⅪ基因内含子4的3′端剪切受位存在c.326-1G>A剪接突变及10号外显子c.1107C>A(p.Tyr351X)复合杂合突变;家系分析表明,先证者-1外婆、母亲及哥哥存在c.326-1G>A杂合剪接突变,奶奶及父亲存在c.1107C>A杂合无义突变。在先证者-1外周血中未能检测到FⅪmRNA。先证者-2 FⅪ基因测序发现8号外显子存在c.841C>T(p.Gln263X)纯合无义突变;家系分析表明先证者-2父亲、母亲、女儿及儿子存在c.841C>T杂合突变。结论 FⅪ基因c.326-1G>A剪接突变、p.Tyr351X和p.Gln263X是导致2个遗传性FⅪ缺陷症先证者FⅪ缺乏的原因。Objective To analyze the phenotype and genotype in two pedigrees with hereditary coagulation factor Ⅺ(FⅪ) deficiency, and investigate the molecular mechanisms of FⅪ deficiency. Methods Two patients with hereditary coagulation FⅪ deficiency were admitted to Chaozhou Central Hospital in Nov 2014 and Jan 2018. The prothrombin time(PT), activated partial thromboplastin time(APTT), FⅪ activity(FⅪ∶C) and FⅪ antigen(FⅪ∶Ag)were tested for phenotypic diagnosis. All the exons and exon-intron boundaries of FⅪ gene of proband were analyzed by PCR and sequencing. The family members were tested for the mutant site of proband. Then the mRNA of FⅪ in the proband was analyzed with RT-PCR. Results The proband-1 was a 7-year-old boy, PT was 10.7 s and APTT was 97.4 s(reference range: 9-12.8 s;24-40 s), FⅪ∶C(0.6%) and FⅪ∶Ag<1%(reference range: 65%-150%;72.1%-122.3%). The proband-2 was a 30-year-old female, and showed the PT(11.7 s), APTT(71.3 s), FⅪ∶C(0.7%) and FⅪ∶Ag<1%.FⅧ∶C, FⅨ∶C and FⅫ∶C of two proband were within the normal range. DNA sequencing showed that the proband-1 had a combined mutation of c.326-1 G>A and c.1107 C>A(p.Tyr351 X) in exon 10. His grandmother, mother and brother had a heterozygous splicing mutation of c.326-1 G>A, his grandmother and father had a homozygous mutation of c.1107 C>A. FXI mRNA was undetected in the proband-1. The proband-2 had a homozygous mutation of c.841 C>T(p.Gln263 X) in exon 8, and this mutation was also found in her father, mother, daughter and son. Conclusion The c.326-1 G>A, c.1107 C>A(p.Tyr351 X) and c.841 C>T(p.Gln263 X) might be the molecular pathogenesis for two probands with hereditary coagulation factor Ⅺ deficiency.

关 键 词：凝血因子Ⅺ缺乏 突变 表型 基因型 系谱 

分 类 号：R596.1[医药卫生—内科学]