Antithrombin Deficiency, SERPINC1 Gene, Next-Generation Sequencing, Varies

Casandra

Casandra Test Code MC83167Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID GNANTCPT Code 81479

Antithrombin Deficiency, SERPINC1 Gene, Next-Generation Sequencing, Varies

Clinical Use

Use

Evaluating antithrombin AT deficiency in patients with a personal or family history suggestive of this hereditary thrombophilia. Confirming an AT deficiency diagnosis with the identification of a known or suspected disease-causing alteration in the SERPINC1 gene, particularly in patients with borderline low AT activity levels. Determining the disease-causing alteration within the SERPINC1 gene to delineate the underlying molecular defect in a patient with a laboratory diagnosis of AT deficiency. Prognosis and risk assessment based on genotype-phenotype correlations. Ascertaining the variant status of family members related to an individual with a confirmed SERPINC1 variant for the purposes of informing clinical management and genetic counseling. Evaluating individuals with apparent heparin resistance.

Special Instructions

This test should only be considered if clinical and family history, initial coagulation screens, and antithrombin (AT) activity and antigen testing results suggest a diagnosis of antithrombin deficiency. This test does not measure AT activity levels. For assessment of AT activity, order ATTF / Antithrombin Activity, Plasma. Submit Rare Coagulation Disorder Patient Information form for a more thorough interpretation.

Limitations

Next-generation sequencing may not detect all types of genomic variants. In rare cases, false-negative or false-positive results may occur. The test is validated to detect 95% of deletions up to 75 base pairs (bp) and insertions up to 47 bp. Larger delins may be less reliably detected. Additionally, the test may not detect low levels of mosaicism or differentiate between somatic and germline variants. Deletions/duplications extending past genes on the panel may not be interpreted. There are regions of homology, high guanine-cytosine content, or repetitive sequences that may evade effective evaluation.

Test Details

New York Approved