Protein S Deficiency In Patients With Pulmonary Embolism Caused By PROS1 Gene Mutation

Background:Venous thromboembolism(VTE),including deep venous thrombosis(DVT)and pulmonary embolism(PE)is caused by damage to the vessel wall,slowing or stopping blood flow velocity,and hypercoagulability of the blood.In recent years,because of its acute onset,clinical manifestations of atypical,high mortality and other characteristics,pulmonary embolism has drawn more and more attention.The hereditary protein S deficiency(PSD)is a established risk factor for venous thrombosis.PSD is an autosomal dominant genetic disease with incomplete penetrance,which is associated with mutations or polymorphisms that encode protein S gene(PROS1),PROS1 has 16 exons,which transits 101 kb at 3q11.2.At present,at home and abroad have identified about 200 kinds of PROS1 mutations caused by PS synthesis or functional changes.However,reports of protein S deficiency leading to pulmonary embolism are rare,and fewer reports of PROS1 gene testing in eligible patients Purpose:By investigating the gene detection of PROS1 and clinical phenotype in patients with protein S deficiency and pulmonary embolism,find the mutation site and summarize the type of mutation.Methods:A total of 40 patients with free protein S activity of less than 50% in patients with pulmonary embolism who underwent pulmonary artery CTA examination from June2011 to December 2016 in Jilin Bethune First Clinical Hospital and 2 patients with normal protein S activity were selected.Collected their peripheral blood 10 ml,centrifugal separation of blood cells and plasma at room temperature,plasma application of the principle of coagulation method to detect free protein S activity,ELISA was used to detect the free protein S quantification,total protein S quantification;blood cell extraction DNA,for PCR amplification and sequencing.The patient's protein S is divided into three types:Type I is characterized by a decrease in total PS,free PS antigen level and PS activity in the patient's blood(type reduction);Type II is characterized by a decrease in the functional activity of PS in thepatient's blood while the total and free PS levels are still normal(Qualitative reduction);Type III is characterized in that the total PS antigen level is within the normal range and the level of free PS antigen is reduced.Results:Free protein S activity of less than 50% of patients in 40 cases,Among them,18 were male(45%),22 were female(55%),male was(54.88 ± 20.42)years old,and female was(56.59 ± 19.09)years old.Among them,hereditary protein S deficiency type: type I: 22 patients(55%);type II: 8 patients(20%);type III: 4 patients(10%);can not be classified: 6 patients(15%).PROS1 gene amplification and sequencing werecarried out,we found in the coding area of 21 different sites of the mutation,mainly distributed in the 2,5,8,10,12,14,16 exon.Of which 15 kinds of mutations in the amino acid changes,while five kinds of mutant amino acid not and a mutation into the termination of the password.In the noncoding region we also found 15 different sites of the mutation,mainly in the 16 exon.Protein S activity in patients with normal 2 cases,including 1 male,aged 60 years,female 1,aged 59 years.Mutations of 15 different loci were found on the coding sequence,mainly on the exon of 2,5,10.Of which 12 kinds of mutations occurred in the amino acid changes,two kinds of mutant amino acid did not change,one mutated into the termination of the password.In the non-coding sequence we also found 10 different sites of the mutation,mainly in the 16 exon.2 patients with normal PS activity were consistent with the results,and found in40 patients with PSD.Compared with the results of 40 patients with PSD: c.783C>T(pro 261 pro)mutation occurred at position 86 in exon 8,but the transcribed amino acid remained proline.The presence of c.2097 A>G(pro 699 pro)mutation at position131 of exon 16 was also synonymous mutation,but this mutation did not occur in all of the 40 patients(36/40).There were 3 patients with exon 12 at the 32 th G had c.1283G>A(ser 428 asn)mutation,leading to amino acid from serine(ser)mutation into asparagine(asn);1 case of exon 12 at the first 140 G c.1391 G>A(arg 464 gin)mutation,leading to amino acid from arginine(arg)mutation into glutamine(gin);1 case of exon12 at the 146 th T c.1397 T>C(val 466 ala)mutation,leading to amino acid from valine(val)mutation into alanine(ala).c.1590 T>C(asn 530 asn)mutation occurred in the second place of exon 14 in 2 patients,but the transcribed amino acid remained asparagine(asn)unchanged.Conclusion:1.A synaptic mutation of two different loci was found in the coding sequence of 40 patients with hereditary protein S deficiency leading to pulmonary embolism.c.783C>T(pro 261 pro)mutation(40/40)occurred at position 86 of exon 8,and c.2097A>G(pro 699 pro)mutation(36/40)occurred at position 131 of exon 16,and these mutations might Causing the occurrence of PSD.2.We found that c.1283 G> A(ser 428 asn)mutations(3/40)occurred in 3patients,and 1 case of c.1391 G> A(arg 464 gin)mutation(1/40),Mutation of c.1397T> C(val 466 ala)occurred in patients(1/40),and c.1590 T> C(asn 530 asn)mutations(2/40)occurred in 2 patients.