Hemophilia A, F8 Gene, Next-Generation Sequencing, Varies

Casandra

Casandra Test Code MC78902Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID GNHMACPT Codes 81265, 81407, 88233, 88235, 88240

Hemophilia A, F8 Gene, Next-Generation Sequencing, Varies

Clinical Use

Use

This test is useful for confirming a clinical diagnosis of hemophilia A in affected male patients by identifying a disease-causing variant in the F8 gene. It determines the disease-causing alteration within the F8 gene to delineate the underlying molecular defect in a male patient with a laboratory diagnosis of hemophilia A. It also identifies the causative alteration for prognostic and genetic counseling purposes, assesses hemophilia A carrier status for female patients with a family history, and enables prenatal testing when a familial F8 variant has been previously identified.

Special Instructions

For male patients, this test should only be considered if clinical and family history, initial coagulation screens, and/or initial activity tests indicate a diagnosis of hemophilia A. For female patients, this test should only be considered if there is a confirmed diagnosis of hemophilia A in a family member or the patient has abnormally low factor VIII (FVIII) activity. Acquired (nongenetic) causes of hemophilia A should be excluded before genetic testing.

Limitations

Next-generation sequencing may not detect all types of genomic variants and may not effectively evaluate regions with technical limitations such as homology, high GC content, and repetitive sequences. The analysis targets single and multi-exon deletions/duplications, but resolution at the single exon level may not always be achieved. Balanced structural rearrangements might not be detected, and the test does not evaluate for the presence of inversions in the F8 gene.

Test Details

New York Approved