Fragile X Molecular Analysis with Reflex to Methylation Testing

Abbrev Code:FRGXMD   
Order Code:LAB3483Order Name:Fragile X Molecular Analysis
Synonyms:FMR1 Premutation
Methodology:AmplideX FMR1 PCR kit (RUO) with a three-primer CGG Repeat Primed (RP) PCR. PCR fragments are sizing on an Applied Biosystems Genetic Analyzer with reflex to methylation status testing for FMR1 repeats of 55 or greater.
CPT Codes: G0452 x1, 81243 x1
Turnaround Time:Results are reported within 10-14 days.
Special Instructions:

This molecular test analyzes only for the trinucleotide repeats in the Fragile-X gene. For molecular and chromosome studies, order Fragile-X Chromosome and Molecular Analysis and submit 5 mL of blood in a green (sodium heparin) tube for Cytogenetics and 10 mL in a yellow ACD (Solution A) tube for Molecular Diagnostics. Test should be ordered through a genetic counselor, or medical geneticist. Patient must be counseled regarding this test: Counseling is available through the Molecular Diagnostics genetic counselor at 612-624-8948. A signed informed consent in the patient's medical record is required; the consent should not be sent to the laboratory. The link to the Genetic Testing Consent Form is provided as a convenience for the providers and genetic counselors.


Bone Marrow Transplant Patients; If a patient is the recipient of an allogeneic transplant, this test must be done on a pre-transplant sample. Contact the Molecular Diagnostics lab to see if a pre-transplant sample is available.


Associated Links:

Genetic Testing Consent Form

Collection Instructions

Optimal Volume:10 mL
Minimum\Peds Volume:5 mL
Container:Yellow (ACD, Solution A) tube available from laboratory
Causes for Rejection:Frozen or clotted specimen, incorrect anticoagulant, specimen more than 5 days old. Patient only tested ONCE; if duplicate sample is collected, testing is canceled, credited and original results and collection date reported. Call 612-273-8445 with questions. Add on testing to hematology samples is not accepted.

Processing and Shipping

Specimen Processing:Store at room temperature.
Shipping Instructions:Ship at room temperature. Do not freeze. Must arrive within 24 hours.
Test Performed at or Referral Lab Molecular Diagnostics  (UMMC East Bank)


Reference Range:Normal, premutation, or affected. Methylation percentage reported for all positive alleles identified. See interpretive report.
Use:The evaluation of x-linked mental retardation or confirmation of clinically diagnosed Fragile X syndrome.

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