Identification of protein Sα gene mutations including four novel mutations in eight unrelated patients with protein S deficiency

Abstract

Summary Eight distinct and potentially causative mutations were identified in eight unrelated Japanese patients with protein S (PS) deficiency, by direct DNA sequencing of the protein Sα (PSα) gene‐specific polymerase chain reaction products of all 15 exons and exon/intron boundaries. There were five missense mutations, including two novel mutations (Cys80Tyr and Arg314His), and three showed a major impact on the expected gene products: novel mutations of a 5‐bp deletion (delCTCTG887:Cys206Stop) and a nonsense mutation (Glu208Stop), as well as a previously reported splice site (exon 10 +5 A→G) mutation. One of the patients showed compound heterozygosity for delCTCTG887 and 732A→G. Investigation for the cosegregation state of these two mutations with PS deficiency in the patient's family suggested that the delCTCTG887 mutation was responsible for the abnormal phenotype and that the 732A→G (Lys155Glu) mutation did not appear to play a key role. However, we also identified the same 732A→G (Lys155Glu) mutation in an unrelated patient with apparent PS deficiency with severe pulmonary embolism, and found that this mutation seemed to cosegregate with a PS‐deficient state in her family members. These data implied that unknown factor(s) other than the 732A→G mutation itself might influence phenotypic expression of PS status in different individuals.

Thrombosis from a Prothrombin Mutation Conveying Antithrombin Resistance

“…The amplicons were sequenced as described previously. 5 To detect the mutation, we performed PCR-restriction-fragment-length polymorphism (RFLP) analysis, using a mismatched lower primer (5′-TGTAGAAGCCATATTTCCCcTgC-3′, with base substitutions at c and g) and introducing a PstI site into the amplicon from a mutant allele. Genomic DNA was isolated from peripheral leukocytes by phenol extraction.…”

One novel and one recurrent mutation in the PROS1 gene cause type I protein S deficiency in patients with pulmonary embolism associated with deep vein thrombosis

“…1) and designated it as protein S Sapporo 1. Protein S Sapporo 1 is a novel mutation of the PROS1 gene that is not described in the 2000 ISTH database of PS mutations [16], the HGMD PROS1 database, or recent reports [12][13][14][15]. The proband, as well as his mother and elder brother, were phenotypically diagnosed with type I deficiency (Table I).…”

“…Type III deficiency is characterized by normal total PS antigen levels, but low free PS antigen levels and low PS activity. According to the Human Gene Mutation Database (HGMD) PROS1 database (URL: http:// archive.uwcm.ac.uk/uwcm/mg/search/120721.html) and recent reports [12][13][14][15], 189 mutations have been identified thus far in the PROS1 gene, most within families with type I and/or type III PS deficiency. Although this classification has been widely used, a newly proposed classification system suggests that PS deficiency can be categorized as quantitative deficiency (old type I and type III deficiency) and qualitative deficiency (type II deficiency), as reported by the 2000 The International Society on Thrombosis and Hemostasis (ISTH) [16].…”

The association of protein S Tokushima-K196E with a risk of deep vein thrombosis

“…We detected PS Tokushima (K196E) using PCR restriction fragment length polymorphism (PCR-RFLP) analysis. We used a mismatch PCR strategy for the PCR-RFLP analysis as reported [19]. PCR was performed using a mismatched primer which introduces a HinfI site only into the mutant allele PCR product.…”