Similar hypercoagulable state and thrombosis risk in type I and type III protein S-deficient individuals from families with mixed type I/III protein S deficiency

SummaryWhile many mutations thought to result in protein S (PS) deficiency are known, there have been few attempts to relate genotype expression with plasma phenotype. We have investigated the nature and consequence of PS gene (PROS1) mutations in 17 PS-deficient families who presented with mixed type I and type III phenotypes. Seven different mutations were found in nine families: delG-34 (STOP codon at –24), Val-24Glu, Arg49Cys, Asn217Ser, Gly295Val, +5 G to A intron j and His623Pro. PS wild type (PSWT) and the five missense mutants were transiently expressed in COS-1 cells. All mutants expressed lower (p<0.05) PS antigen compared to PSWT (100%). The mutants Val-24Glu, Gly295Val and His623Pro expressed very low/undetectable PS levels. The mutant Asn217Ser produced around 30% of PSWT, while the mutant Arg49Cys had the highest PS levels (around 50%). Metabolic labelling and pulse-chase experiments showed that all of the mutants had impaired secretion, but this was of variable severity. Also, enhanced intracellular degradation of unsecreted material was found for all mutants. There was a strong correspondence between plasma free PS levels in carriers of the mutations, secreted PS from transfected COS-1 cells and labelled PS from 24 h conditioned medium in pulse-chase experiment. We conclude that the magnitude of secretion defect depends on the nature of the PROS1 mutation and influences the level of free PS in plasma. It is likely that the severity of the secretion defect will determine the risk for venous thrombosis.

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Genetic and Phenotypic Analysis of a Large (122-Member) Protein S–Deficient Kindred Provides an Explanation for the Familial Coexistence of Type I and Type III Plasma Phenotypes

Blood ◽

10.1182/blood.v89.12.4364 ◽

1997 ◽

Vol 89 (12) ◽

pp. 4364-4370 ◽

Cited By ~ 58

Author(s):

Rachel E. Simmonds ◽

Bengt Zöller ◽

Helen Ireland ◽

Elizabeth Thompson ◽

Pablo Garcı́a de Frutos ◽

...

Keyword(s):

Total Protein ◽

Family Members ◽

Protein S ◽

Type I ◽

Protein S Deficiency ◽

Antigen Level ◽

Phenotypic Analysis ◽

Type Iii ◽

S Deficiency ◽

Free Antigen

Abstract Protein S deficiency is a known risk factor for thrombosis. The coexistence of phenotypic type I (reduction in total and free antigen) and type III (reduction in free antigen only) protein S deficiencies in 14 of 18 families was recently reported. We investigated the cause of this phenotypic variation in the largest of these families (122 family members, including 44 affected individuals) using both molecular genetic and phenotypic analysis. We have identified a sole causative mutation (Gly295Val) in three family members representative of the variable phenotype. Complete cosegregation of the mutation with reduced free protein S antigen levels was found, regardless of the total antigen level. Analysis of phenotypic data showed high correlations between total protein S antigen and age in both normal and protein S–deficient family members, irrespective of gender. Free protein S antigen levels were not influenced by age, a finding explained by an association between β-chain containing C4b-binding protein (C4bBP-β+) antigen levels and age. We propose that the identified Gly295Val mutation causes quantitative, or type I, protein S deficiency, and that as age increases the total protein S antigen level normalizes with respect to the reference plasma pool, giving rise to a type III protein S–deficient phenotype.

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Evaluation of the relationship between protein S and C4b-binding protein isoforms in hereditary protein S deficiency demonstrating type I and type III deficiencies to be phenotypic variants of the same genetic disease

Blood ◽

10.1182/blood.v85.12.3524.bloodjournal85123524 ◽

1995 ◽

Vol 85 (12) ◽

pp. 3524-3531 ◽

Cited By ~ 89

Author(s):

B Zoller ◽

P Garcia de Frutos ◽

B Dahlback

Keyword(s):

Genetic Disease ◽

Plasma Concentrations ◽

Protein S ◽

Type I ◽

Protein S Deficiency ◽

Free Protein ◽

Type Iii ◽

S Deficiency ◽

Low Levels ◽

The Relationship

Type III protein S deficiency is characterized by a low plasma level of free protein S, whereas the total concentration of protein S is normal. In contrast, both free and total protein S levels are low in type I deficiency. To elucidate the molecular mechanism behind the selective deficiency of free protein S in type III deficiency, the relationship between the plasma concentrations of beta-chain containing isoforms of C4b-binding protein (C4BP beta+) and different forms of protein S (free, bound, and total) was evaluated in 327 members of 18 protein S-deficient families. In normal relatives (n = 190), protein S correlated well with C4BP beta+, with free protein S (96 +/- 23 nmol/L) being equal to the molar excess of protein S (355 +/- 65 nmol/L) over C4BP beta+ (275 +/- 47 nmol/L). In protein S-deficient family members (n = 117), the equimolar relationship between protein S (215 +/- 50 nmol/L) and C4BP beta+ (228 +/- 51 nmol/L), together with the high affinity of the interaction, resulted in low levels of free protein S (16 +/- 10 nmol/L). Free protein S levels were distinctly low in protein S-deficient members, whereas in 47 of the protein S-deficient individuals, the concentration of total protein S was within the normal range, which fulfils the criteria for type III deficiency. The remaining 70 had low levels of both total and free protein S and, accordingly, would be type I deficient. Coexistence of type I and type III deficiency was found in 14 families, suggesting the two types of protein S deficiency to be phenotypic variants of the same genetic disease. Interestingly, not only protein S but also C4BP beta+ levels were decreased in orally anticoagulated controls and even more so in anticoagulated protein S-deficient members, suggesting that the concentration of C4BP beta+ is influenced by that of protein S. In conclusion, our results indicate that type I and type III deficiencies are phenotypic variants of the same genetic disease and that the low plasma concentrations of free protein S in both types are the result of an equimolar relationship between protein S and C4BP beta+.

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Free and Total Protein S Antigen Levels on the Risk of Venous Thrombosis: Results From the MEGA Study

Blood ◽

10.1182/blood.v118.21.538.538 ◽

2011 ◽

Vol 118 (21) ◽

pp. 538-538

Author(s):

Daniel D. Ribeiro ◽

Maria Carolina T. Pintao ◽

Willem M. Lijfering ◽

Pieter H. Reitsma ◽

Frits R. Rosendaal

Keyword(s):

Venous Thrombosis ◽

Total Protein ◽

Protein S ◽

Type I ◽

Protein S Deficiency ◽

Blood Draw ◽

Free Protein ◽

Type Iii ◽

S Deficiency ◽

Increased Risk

Abstract Abstract 538 Context: Conflicting data have been reported on the risk for venous thrombosis in individuals with low total protein S levels (i.e. type I protein S deficiency) and low free protein S levels with normal total protein S levels (i.e. type III protein S deficiency). This may be due to small numbers, wrong cut off level or inclusion of individuals with mild transitory decrements in protein S levels. Most studies that showed that type I and type III protein S deficiency were related with an increased risk for venous thrombosis, have been performed in thrombophilic families, suggesting that these deficiencies are inherited. As the prevalence of inherited type I or type III protein S deficiency is not known, the relevance of these findings within normal populations remain to be established. Objectives: To assess the risk of first venous thrombosis in persons with low levels of free protein S or total protein S in a large population-based case–control study. Design: MEGA study, 4956 consecutive patients aged 18 to 70 years with a first episode of venous thrombosis were included. Age- and sex-matched controls were partners of patients (n=3297) or individuals recruited by random digit dialing (n=3000). DNA was obtained by standard methods and was available for 4485 patients and 4889 control subjects. Citrated plasma was available for 2471 patients and 2940 controls. Molecular basis for protein S deficiency was investigated by analysis of copy number variation of PROS1 and sequencing of individuals with the lowest levels of protein S in attempt to explain the different findings in risk estimates between families and population studies. Statistical analysis: Odds ratios were adjusted for age and sex (matching factors) for levels of free/total protein S and their 95% confidence levels (95% CIs) with the use of logistic regression. The 2.5th-97.5th percentile of both total and free protein S in control subjects that did not use vitamin K antagonists (VKA) at time of blood draw were considered as the reference range. Individuals that used VKA at time of blood draw were excluded when calculating relative risk estimates. Furthermore, a preplanned sensitivity analysis was performed where we excluded estrogen users and pregnant women at time of blood draw. Results: Individuals with low free protein S levels or low total protein S levels (<2.5th percentile) were not at increased risk of venous thrombosis as compared to individuals with protein S levels in the 2.5th-97.5th percentile; odds ratio 0.82 (95% CI, 0.56–1.21) and 0.90 (95% CI, 0.62–1.31) respectively. Excluding all women who used estrogens or were pregnant/puerperic at time of venous thrombosis or at time of blood sampling increased the odds ratios slightly to 1.55 (95% CI, 0.84–2.88) for individuals with low free protein S levels and to 1.28 (95% CI, 0.70–2.35) in individuals with low total protein S levels. We subsequently compared decreasing cut off values of free and total protein S levels on the risk of venous thrombosis as compared to the same reference group. Although numbers became small, it appeared that a free protein S cut off level of < 0.20th or < 0.10th percentile could identify individuals at high risk of venous thrombosis (odds ratios 2.01; 95% CI, 0.57–7.15, and 5.44; 95% CI, 0.61–48.78, respectively). Even extremely low (<0.10th percentile) total protein S levels were not associated with venous thrombosis. Only one patient had a copy number variation of PROS1 in 2270 consecutive samples tested. Currently, we are sequencing the PROS1 gene in all individuals with protein S levels <1st percentile of which results will be available before the ASH conference of 2011. Conclusion: Low free protein S and low total protein S levels could not identify individuals at risk for venous thrombosis in a population based study. Although extremely low free protein S levels were associated with an increased risk for venous thrombosis, numbers were too small to support testing on free protein S in an unselected group of venous thrombosis patients. Disclosures: No relevant conflicts of interest to declare.

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The Frequency of Type I Heterozygous Protein S and Protein C Deficiency in 141 Unrelated Young Patients with Venous Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642558 ◽

1988 ◽

Vol 59 (01) ◽

pp. 018-022 ◽

Cited By ~ 139

Author(s):

C L Gladson ◽

I Scharrer ◽

V Hach ◽

K H Beck ◽

J H Griffin

Keyword(s):

Venous Thrombosis ◽

Protein C ◽

Antithrombin Iii ◽

Young Patients ◽

Protein S ◽

Type I ◽

Protein S Deficiency ◽

Protein C Deficiency ◽

Low Protein ◽

S Deficiency

SummaryThe frequency of heterozygous protein C and protein S deficiency, detected by measuring total plasma antigen, in a group (n = 141) of young unrelated patients (<45 years old) with venous thrombotic disease was studied and compared to that of antithrombin III, fibrinogen, and plasminogen deficiencies. Among 91 patients not receiving oral anticoagulants, six had low protein S antigen levels and one had a low protein C antigen level. Among 50 patients receiving oral anticoagulant therapy, abnormally low ratios of protein S or C to other vitamin K-dependent factors were presented by one patient for protein S and five for protein C. Thus, heterozygous Type I protein S deficiency appeared in seven of 141 patients (5%) and heterozygous Type I protein C deficiency in six of 141 patients (4%). Eleven of thirteen deficient patients had recurrent venous thrombosis. In this group of 141 patients, 1% had an identifiable fibrinogen abnormality, 2% a plasminogen abnormality, and 3% an antithrombin III deficiency. Thus, among the known plasma protein deficiencies associated with venous thrombosis, protein S and protein C. deficiencies (9%) emerge as the leading identifiable associated abnormalities.

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A Mutation in the Protein S Pseudogene Is Linked to Protein S Deficiency in a Thrombophilic Family

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651024 ◽

1989 ◽

Vol 62 (03) ◽

pp. 897-901 ◽

Cited By ~ 10

Author(s):

Hans K Ploos van Amstel ◽

Pieter H Reitsma ◽

Karly Hamulyák ◽

Christine E M de Die-Smulders ◽

Pier M Mannucci ◽

...

Keyword(s):

Total Protein ◽

Protein S ◽

Southern Analysis ◽

Type I ◽

Protein S Deficiency ◽

S Deficiency ◽

The Family ◽

Dna Pattern ◽

Deficiency Type ◽

S Genes

SummaryProbands from 15 unrelated families with hereditary protein S deficiency type I, that is having a plasma total protein S concentration fifty percent of normal, were screened for abnormalities in their protein S genes by Southern analysis. Two probands were found to have a deviating DNA pattern with the restriction enzyme Mspl. In the two patients the alteration concerned the disappearance of a Mspl restriction site, CCGG, giving rise to an additional hybridizing Mspl fragment.Analysis of relatives of both probands showed that in one family the mutation does not co-segregate with the phenotype of reduced plasma protein S. In the family of the other proband, however, complete linkage between the mutated gene pattern and the reduced total protein S concentration was found: 12 heterozygous relatives showed the additional Mspl fragment but none of the investigated 26 normal members of the family. The mutation is shown to reside in the PSβ gene, the inactive protein S gene. The cause of type I protein S deficiency, a defect PSα gene has escaped detection by Southern analysis. No recombination has occurred between the PSα gene and the PSβ gene in 23 informative meioses. This suggests that the two protein S genes, located near the centromere of chromosome 3, are within 4 centiMorgan of each other.

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Protein S mRNA in Patients with Protein S Deficiency

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653862 ◽

1995 ◽

Vol 73 (05) ◽

pp. 746-749 ◽

Cited By ~ 5

Author(s):

E Sacchi ◽

M Pinotti ◽

G Marchetti ◽

G Merati ◽

L Tagliabue ◽

...

Keyword(s):

Gene Polymorphism ◽

Total Protein ◽

Restriction Analysis ◽

Protein S ◽

Type I ◽

Protein S Deficiency ◽

Phenotypic Analysis ◽

S Deficiency ◽

Deficiency Type ◽

S Genes

SummaryA protein S gene polymorphism, detectable by restriction analysis (BstXI) of amplified exonic sequences (exon 15), was studied in seven Italian families with protein S deficiency. In the 17 individuals heterozygous for the polymorphism the study was extended to platelet mRNA through reverse transcription, amplification and densitometric analysis. mRNA produced by the putative defective protein S genes was absent in three families and reduced to a different extent (as expressed by altered allelic ratios) in four families. The allelic ratios helped to distinguish total protein S deficiency (type I) from free protein S deficiency (type IIa) in families with equivocal phenotypes. This study indicates that the study of platelet mRNA, in association with phenotypic analysis based upon protein S assays in plasma, helps to classify patients with protein S deficiency.

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