蛋白S基因突变导致深静脉血栓形成的研究

Recurrent deep vein thrombosis caused by heterozygous missense mutation of the protein S gene:genetic analysis of a case

目的了解1例青少年起病的复发性深静脉血栓形成(DVT)患者蛋白S(PS)缺乏的分子发病机制。方法收集患者及其家系成员的血标本,进行凝血和抗凝指标的检测。凝血功能的检测采用一步凝固法,蛋白C、蛋白S的活性检测采用发色底物法,蛋白S抗原检测采用ELISA方法。对患者及其家系成员的PS基因各外显子片段及外显子内含子侧翼序列进行PCR扩增和产物送测序分析。结果患者及其父亲为遗传性PS缺乏患者,其PS基因第10号外显子发生了C82792T杂合点突变,导致PS蛋白氨基酸肽链第314个精氨酸残基(R)被半胱氨酸残基(C)所替换,发生R314C杂合突变。结论患者反复发作DVT系由PS基因错义杂合突变导致的遗传性PS缺乏所致,该基因突变为国际上首次报道。

Objective To analyze the molecular pathogenesis of protein S deficiency in an adolescent case of recurrent deep vein thrombosis（DVT）.Methods Blood samples from the patient and his family members were collected for detection of the coagulation parameters by one-step clotting method,and the protein S（PS） and protein C activities were measured by a chromogenic assay.Enzyme-linked immunosorbent assay was employed for detecting the levels of free PS antigen.All the exons and exon-intron boundaries of the patients’PS gene were amplified using PCR and analyzed by direct sequencing.Results As carriers of hereditary PS deficiency,both the patient and his father showed a heterozygous C82792T point mutation in the 10th exon of their PS gene which resulted in the substitution of arginine314 by cysteine in the polypeptide chain of PS protein.Conclusion Recurrence of DVT in this patient is the result of hereditary PS deficiency caused by a novel heterozygous missense mutation in the PS gene.