Test Directory
Protein S Gene Sequencing
Justification
Specimen Requirements
| Sample Type | Volume Required | Minimum Volume | Stability | |
|---|---|---|---|---|
| PREFERRED | EDTA Whole Blood | 3mL | 1mL | Room Temp.: 1 month Refrigerated: 1 month |
| ALTERNATIVE | Cheek swab | 2 swab | - | Room Temp.: 1 month Refrigerated: 1 month |
| REJECTION CRITERIA | Sample contamination; sample compromised |
| SPECIAL INSTRUCTIONS | - |
General Information
| METHODOLOGY | NGS |
| STAT TAT | < 48 hours (M-F) |
| STAT TAT Performance | > 90% of results released in 48 hours |
| ROUTINE TAT | < 5 days (M-F) |
| ALTERNATIVE NAMES | PROS1 gene sequencing, PS gene sequencing |
| DESCRIPTION | This test sequences the exons plus 5bp of the flanking introns of the PROS1 gene. Sanger sequencing may be used to confirm variants as needed. Congenital protein S deficiency is associated with thrombophilia and an increased risk of thromboembolism; it is caused by mutations in the PROS1 gene. The prevalence of severe protein S deficiency is rare while mild protein S deficiency may be as common as 1 in 500. Individuals with mild protein S deficiency are at an elevated risk of developing a deep vein thrombosis (DVT) and pulmonary embolism (PE). In severe cases of protein S deficiency, infants develop a life-threatening blood clotting disorder called purpura fulminans soon after birth. Rapid genetic testing may be recommended to confirm functional protein S defects in infants. Ordering the protein S activity, free antigen and total antigen are recommended to assess the functional and antigenic impact of any identified PROS1 gene variants |
| LIMITATIONS | This test will not detect variants located outside of the targeted DNA regions. This test is not optimized to detect chimerism or somatic mosaicism. This test will detect small indels but may miss larger deletions or duplications. Balanced structural variants will not be detected unless specifically targeted by a custom PCR assay. |
| NORMAL RANGE | Interpretation: Negative |
| ASSOCIATED TESTING | - |
| REFERENCES | Dahlbäck B. Vitamin K-Dependent Protein S: Beyond the Protein C Pathway. Semin Thromb Hemost. 2018 Mar;44(2):176-184. |
| SAMPLE REPORT | Upon request |
| NEW YORK STATE APPROVED | No |
Test Codes
| ORDER CODE | P3375 |
| CPT CODE | 81479 |
| LOINC CODE | 92994-3 |