MDL Fragile X-CGG Nmbr DNA Mut (FXM)
Department: Molecular Diagnostics
Test Synonym(s): LAB3032, FXM, FRAGILE X GENE (FMR1), Fragile X Mutation, Fragile X-CGG DNA Mutation
CPT Codes: 81243
Methodology: Direct Detection of CGG Expansion Mutation by PCR and capillary electrophoresis
Tube Type: Lavender top (EDTA)
Specimen: Whole blood; purified DNA - 1µg (NOTE: refer to Reasons for Rejection for DNA extraction criteria)
Alternate Specimen: Dark green top (Sodium Heparin)
Pediatric Requirements: 2 microtainers
Volume: 1 tube
Minimum Volume: 2 microtainers; purified DNA - 100ng
Temperature: EDTA, Sodium Heparin: room temperature or refrigerated, purified DNA: refrigerate or freeze
Stability: EDTA, Sodium Heparin - Room temperature: 2 days Refrigerated: 7 days; Purified DNA - indefinitely @ -70°C
Reasons for Rejection: Client will be notified by Molecular Diagnostics Lab if specimen is rejected. Purified DNA - externally extracted nucleic acid received for clinical testing only accepted from CLIA-certified laboratories or laboratories meeting equivalent requirements as determined by College of American Pathologists (CAP) and/ or CMS. Documentation stating that the DNA was extracted in a CLIA lab will be required and should accompany the DNA specimen. DNA samples received from facilities not meeting requirement will be rejected. The Molecular Diagnostic Laboratory medical director will contact the referral facility.
Days Performed: Once a week - variable days
Times Performed: Batched
TAT: 10 days
Significance: Direct Detection of CGG Expansion in the FMR1 Gene
Special Instructions: Call or email the Molecular Diagnostics Laboratory at 615-343-8121 or moleculardiagnosticlab@vumc.org if assistance is needed for specimen submission or if the patient has received a transfusion in the prior 2 weeks or has a history of a stem cell transplant.
Click here to print the Molecular Diagnostics requisition.
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