نیلوفر سلیمانی - Department of Hematology and Blood Transfusion, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
محمد رضا رضوانی - Department of Hematology and Blood Transfusion, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
محمود شمس - Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
اکبر درگلاله Dorgalaleh - Hamin Tis Research Institute, Tehran, Iran
شادی طبیبیان - Iranian Comprehensive Hemophilia Care Center, Tehran, Iran
فرهاد ذاکر - Department of Hematology and Blood Transfusion, Faculty of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran

Background and Aims: Protein S (PS) is a vitamin K-dependent glycoprotein synthesized by endothelial and somatic cells that acts as an anticoagulant in its free form and an inhibitor of the complement system in its bound form. Deficiency of PS is a congenital thrombophilia that can have significant clinical consequences. This study aimed to report the clinical and genetic characterization of four Iranian patients with PS deficiency. Materials and Methods: In this study, we investigated the genetic basis of PS deficiency in four Iranian patients from three unrelated families, including two females and two males with a mean age of ۳۲.۵(± ۲۵.۷۳) years. Whole blood was collected to measure PS total antigen levels and isolated genomic DNA, which was then amplified using polymerase chain reaction to direct sequencing of the PROS۱ gene with the Sanger method. Each novel variation was subjected to in silico analysis. Results: Two novel variants in the PROS۱ gene were identified: c.-۱۹۶ C > G in exon ۱ and c.۱۹۸A > C in exon ۲. In this setting, both variants were present in a heterozygous state in patient C۱ and a homozygous state in patient C۲. In addition, a silico analysis was conducted to assess the impact of the identified variants, showing that the c.۱۹۸A > C variant was likely detrimental and the c.۱۹۸A > C variant was likely pathogenic. Conclusion: The results highlight the heterogeneity of PS deficiency and the need for further investigation to identify additional mutations and understand the genetic basis of this condition in the Iranian population.

Genotyping, PROS۱ gene, Protein S deficiency, Thrombophilia, Protein S Deficiency, PROS۱ gene, Thrombophilia, Genotyping