Hemophilia A F8 Gene, Intron 22 Inversion Mutation Analysis, Prenatal

Casandra

Casandra Test Code MC64082Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID F822PCPT Code 81403

Hemophilia A F8 Gene, Intron 22 Inversion Mutation Analysis, Prenatal

Clinical Use

Use

This test is used for prenatal testing for hemophilia A when an F8 intron 22 inversion has been identified in a family member. The intron 22 inversion accounts for approximately 45 percent of variants associated with severe hemophilia A. A known family inversion is required for analysis. Knowledge of familial inversion enables targeted prenatal diagnosis. If the familial inversion is not detected in an affected male or obligate female carrier, further methods such as F8 sequencing may be considered.

Special Instructions

Reflex tests may be ordered at additional charge depending on specimen type: CULAF (amniotic fluid culture), CULFB (fibroblast culture), MATCC (maternal cell contamination studies), or STR-based compensation analyses. A maternal whole blood specimen is required to perform maternal cell contamination studies. Methodology used is Inverse Shifting‑Polymerase Chain Reaction (IS‑PCR). New York state availability: Yes.

Limitations

Inversion analysis is only valid if the familial intron 22 inversion is known. Absence of this inversion does not rule out other F8 mutations; additional testing like F8 sequencing may be necessary. Reflex testing incurs additional charges. Interpretation depends on quality and type of prenatal specimen and avoidance of maternal cell contamination.

Test Details

New York Approved