Hirose Masaya, Kimura Fuminori, Wang Hua-Qin, Takebayashi Koichi, Kobayashi Masashi, Nakanishi Keiko, Akiyama Minoru, Kimura Toshio, Noda Yoichi
Department of Obstetrics and Gynecology, Shiga University of Medical Science, Ohtsu, Japan.
J Thromb Thrombolysis. 2002 Apr;13(2):85-8. doi: 10.1023/a:1016294730165.
We attempted to identify a gene defect in a young woman with type III protein S deficiency and venous thrombosis during pregnancy.
Measurements of total and free PS antigen levels in plasma were carried out using an enzyme-linked immunosorbent assay. Plasma PS cofactor activity was determined by a clotting assay using activated factor V as the substrate. Genomic DNA prepared from peripheral blood was amplified by polymerase chain reaction (PCR) with PROS1-specific oligonucleotide primers. PCR products were sequenced on both strands using specific oligonucleotide primers.
Plasma PS cofactor activity was undetectable in every measurement at 36 weeks of gestation, as well as at 2 weeks and 4 months after delivery. Plasma total PS antigen levels were 70% and 67% at 2 weeks and 4 months after delivery, respectively. Free PS antigen level was 24% at 4 months after delivery. Of all exons analyzed, codon 295 of GGC in exon 10 was substituted for AGC. This missense mutation predicted an amino acid change of glycine to serine.
Measurements of total and free PS antigen levels along with PS activity indicated that this was a case of type III PS deficiency. DNA analysis identified a heterozygous missense mutation of codon 295 in the PS gene, substituting glycine for serine.
我们试图在一名患有III型蛋白S缺乏症且在孕期发生静脉血栓形成的年轻女性中鉴定基因缺陷。
采用酶联免疫吸附测定法检测血浆中总蛋白S和游离蛋白S抗原水平。以活化因子V为底物，通过凝血测定法测定血浆蛋白S辅因子活性。使用PROS1特异性寡核苷酸引物，通过聚合酶链反应（PCR）扩增从外周血制备的基因组DNA。使用特异性寡核苷酸引物对PCR产物的两条链进行测序。
在妊娠36周时以及分娩后2周和4个月的每次检测中均未检测到血浆蛋白S辅因子活性。分娩后2周和4个月时血浆总蛋白S抗原水平分别为70%和67%。分娩后4个月时游离蛋白S抗原水平为24%。在所有分析的外显子中，第10外显子中GGC的第295密码子被替换为AGC。这种错义突变预测甘氨酸会变为丝氨酸。
总蛋白S和游离蛋白S抗原水平以及蛋白S活性的检测表明，这是一例III型蛋白S缺乏症病例。DNA分析鉴定出蛋白S基因中第295密码子存在杂合错义突变，导致甘氨酸被丝氨酸替代。
