遗传性FⅪ缺陷症出现双重杂合基因突变的分析  

Analysis on the novel compound heterozygous mutation F XI of a patient with hereditary factor XI deficiency

作　　者：许锴 舒旷怡[2] 李帆帆[2] 陈陶[2] 柳洁[2] 金速速 郭晶晶[2] 章赵华[2] 江明华[2] 

机构地区：[1]浙江省温州市人民医院检验科,325000 [2]温州医科大学附属第二医院育英儿童医院医学检验中心

出　　处：《中华医学杂志》2017年第48期3774-3778,共5页National Medical Journal of China

基　　金：浙江省自然科学基金（LY13H200003）;温州市科技计划项目（Y20140431）;温州市公益性科技计划项目（Y20140674）

摘　　要：目的分析一个中国汉族遗传性凝血因子Ⅺ（FⅪ）缺陷症家系的表型和基因缺陷特征，探讨F11基因的突变类型和临床表型的关系。方法采用凝固法检测先证者及家系成员的活化部分凝血活酶时间（APTT）、凝血酶原时间（PT）、凝血因子Ⅺ活性（FⅪ：C）等指标进行表型诊断；酶联免疫吸附测定方法（ELISA）检测凝血因子Ⅺ抗原（FⅪ：Ag）；提取外周血基因组DNA，对先证者及家系成员F11基因1～15号外显子及侧翼序列进行PCR扩增和测序，对105名健康对照者DNA相应突变区域进行PCR扩增和测序，与人类基因组突变数据库比对寻找突变位点并排除基因多态性；使用Pymol软件分析突变对FⅪ蛋白质结构及功能的影响。结果先证者APTT为74．2s，FⅪ：C为4．0％，FⅪ：Ag为2．9％；先证者姐姐APTT为67．1s，FⅪ：C为3．0％，FⅪ：Ag为1．8％；健康对照者APTT为34．5s，FⅪ：C为100．0％，FⅪ：Ag为100．0％；先证者父、母和弟弟FⅪ：C分别为72．0％、62．0％、78．0％；FⅪ：Ag分别为50．0％、43．0％、51．8％。先证者及家系成员其他凝血指标均正常。测序发现先证者及其姐姐F11存在双重杂合突变，外显子12的1491位碱基T缺失导致了移码突变，使465位氨基酸由亮氨酸突变为色氨酸，在突变位点后第7位出现终止密码子：F11NM_13142c．1491delT（P．Leu465Trp．fs＊7）；外显子15的1815位碱基G变为A，密码子由GGC变为GAC，导致错义突变F11 NM_13142c．1815G〉A（P．Gly573Asp）。其父和其弟弟为F11NM_13142c．1491delT（P．Leu465Trp．fs＊7）杂合突变者；其母为P．G1y573Asp杂合突变者，先证者舅舅F11基因为正常野生型。结论F11NM_13142c．1491delT（P．Leu465Trp．fs＊7）和F11NM_13142c．1815G〉A（P．Gly573Asp）双重杂合突变是导致先证者遗传性FⅪ缺陷症的分子致病原因，引起FⅪ抗原和活性同时降低。Objective To investigate the clinical phenotype and genotype characteristics of a Chinese hereditary factor XI deficiency pedigree. Methods The activated partial thromboplastin time （ APIT）, prothrombin time （ PT）, FXI activity （ FXI ： C） were measured by clotting method using automatic coagulation analyzer. The F XI antigen （F XI：Ag ） was assayed by enzyme-linked immunosorbent assay （ELISA）. Fifteen exons of F11 from the proband and his pedigree members were amplified by polymerase chain reaction （PCR）, then sequenced. Pymol software was used to analyze the novel mutations. Results AFTT, FXI：C and FXI：Ag of proband was 74. 2 s, 4. 0% and 2. 9% , respectively. For his older sister, AFTT, FXI ：C and FXI ： Ag was 67.1 s, 3.0% and 1.8% , respectively. AFTT, FXI ： C and FXI ： Ag of healthy controls were 34. 5 s, 100.0% and 100. 0%. FXI ：C of prohand＇s father, mother and brother were 72. 0%, 62. 0%, and 78.0%, respectively. FXI：Ag of them were 50. 0%, 45.0%, and 51.8%, respectively. The other coagulant parameters of the proband and his pedigree were all in the normal range. Sequence analysis showed two heterozygous gene mutations in F11 of the proband and his older sister. One was a deletion of T at nucleotide 1 491 in exon 12, resulting in a frameshift. A substitution of leucine 465 by tryptophan and a terminal coden after 7 amino acid：FllNM_13142c. 1491delT （p. Leu465Trp. fs ＊ 7）. The other was a G to A substitution at nucleotide 1 815 in exon 15, resulting in a substitution of glycine 573 by aspartic acid：Fll NM_13142c. 1815G 〉 A （p. Gly573Asp）. FIlNM_131g2c. lg91delT （p. Leu465Trp. fs ＊ 7） heterozygotes were found both in the proband＇s father and his brother while p. Gly575Asp heterozygote was only found in his mother. Fll of the proband＇s uncle was wild. Conclusion The novel compound heterozygous mutations of FllNM_13142c. 1491delT （ p. Leu465Trp. fs ＊ 7） and Fll NM_13142 c. 1815G 〉 A （p. Gly573Asp） are responsible for FXI deficie

关 键 词：因子Ⅺ 基因 突变 

分 类 号：R440[医药卫生—诊断学] R596.1[医药卫生—临床医学]