抗凝血酶基因10381T缺失导致的Ⅰ型抗凝血酶缺陷症

Type Ⅰ antithrombin deficiency due to 10381T deletion in antithrombin gene

目的对1例遗传性抗凝血酶(AT)缺陷症先症者及其家系进行表型诊断和基因诊断,并探讨其家系成员发病机制。方法用发色底物法检测该家系9名成员的AT活性(AT∶A)、蛋白S活性(PS∶A)、蛋白C活性(PC∶A),用免疫比浊法检测AT抗原量(AT∶Ag),用Western blot检测血浆中的AT分子质量和含量,抽提外周血基因组DNA,用PCR对AT基因的7个外显子及其侧翼序列进行扩增,用直接测序法对该家系所有成员的扩增产物进行测序分析并进行基因突变检测,同时筛查100例正常人以排除基因突变的多态性。结果该家系先症者AT∶A和AT∶Ag分别为48%和121 mg/L,先症者AT基因的第6外显子发现10381T del。其家系的部分成员检测到相同的移码突变。结论该家系先症者及部分成员存在Ⅰ型遗传性抗凝血酶缺陷症,是由AT基因10381T del移码突变所致。

Objective To make a phenotype diagnosis and gene diagnosis aiming directly at one case of hereditary antithrombin （AT） deficiency syndrome of proband and their family phenotype, and explore the pathogenesis of family members. Methods The activity of AT（ AT： A） , protein S and protein C were detected by chromogenic sub strate method, with immune turbidimetry on AT antigen （AT： Ag） detection, the molecules weight and content of AT were detected by Western bloting method, Genomic DNA was extracted from blood, the 7 exons of AT and flan king sequences were amplified by PCR, products of PCR of all family members were conducted by direct sequen cing analysising and gene mutation detection, screening 100 cases of normal people to exclude the of polymorphism of gene mutation. Results The AT： A and AT： Ag of proband was 48% and 121 mg/L respectively, the proband＇ sixth exon of AT gene is c. 10381T del. Some members of the family were detected the same frameshift mutations.Conclusions The pedigree and some members of the first symptoms are type Ⅰ hereditary antithrombin deficiency due to AT gene 10381T del ffameshift mutations.