Pedigree analysis of three Chinese pedigree affected with hereditary protein S deficiencies caused by frameshift variants of PROS1 gene
10.3760/cma.j.cn114452-20250304-00129
- VernacularTitle:移码突变导致的遗传性蛋白S缺陷症3个家系分析
- Author:
Haiyue ZHANG
1
;
Shuang LIANG
1
;
Xinyang YUE
1
;
Tenglong DAI
1
;
Jun WU
1
Author Information
1. 首都医科大学附属北京积水潭医院医学检验中心，北京 100035
- Publication Type:Journal Article
- Keywords:
Protein S deficiency;
Gene variant;
PROS1 gene;
Bioinformatics
- From:
Chinese Journal of Laboratory Medicine
2025;48(8):1034-1040
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the phenotypes and gene mutations of the three families with hereditary protein S (PS) deficiency caused by frameshift heterozygous variants.Methods:Case report and case series study. We investigate three probands and their family members (14 people from three generations) who registrated in Beijing Jishuitan Hospital of Capital Medical University from Feb 1st to 28th, 2025. The clinical data of the three probands and their family members were collected. The related coagulation tests of all members were detected. Protein S activity (PS:A) was determined using coagulation assay, and total protein S antigen (TPS:Ag) and free protein S antigen (FPS:Ag) were measured using ELISA. All exons and their flanking sequences of the probands were amplified using PCR technique, and gene analysis by direct sequencing, and variant genes were searched which were then verified by cloning sequencing, meanwhile, the corresponding variant loci of the family members were analyzed. A calibrated automated thrombin generation (CAT) method was used to study thrombin production. ClustalX-2.1-win software was used to analyze the conservatism of the mutant loci; Mutation Taster and Franklin.genoox online bioinformatics software were used to predict the pathogenicity of the mutant loci; PyMol software was used to analyze the changes in protein spatial structure before and after mutation.Results:The PS:A, TPS:Ag and FPS:Ag of the three probands with hereditary PS deficiency were decreased. Genetic sequencing identified a total of three PROS1 genetic variants, and all the three probands were heterozygous frameshift variants: p.Gln51Argfs*2 in Proband A; p.Met251Valfs*17 in Proband B; and Thr478tyrfs*21 in Proband C. Conservative analysis showed that p.Gln51, p.Met251 and p.Thr478 loci were not conserved among the homologous species; Mutation Taster and Franklin.genoox analysis showed that these variants were pathogenic; protein structure model analysis showed that p.Gln51Argfs*2, p.Met251Valfs*17 and p. Thr478Tyrfs*21 variants may result in altered protein spatial structure.Conclusion:The heterozygous frameshift variations of PS p.Gln51Arg fs*2, p.Met251Valfs*17 and p.Thr478Tyrfs*21 would alter the spatial structure of PS molecules, and reduce their structural stability, leading to PS deficiency.
