FMR1 Triplet Repeat (CGG) Testing

Omics test Model
Test Code D4042
Test Summary

This test detects CGG repeat expansion in the FMR1 gene.
Turn Around Time 10 - 14 days
Acceptable Sample Types DNA, Isolated , Dried Blood Spots , Saliva , Whole Blood (EDTA)
Acceptable Billing Types Institutional Billing , Self (patient) Payment
NY Approved No
CPT Codes** 81244(x1)
*TAT starts after the sample and all required sample information is received at the processing laboratory.

**The CPT codes listed are in accordance with Current Procedural Terminology, a publication of the American Medical Association, and are provided for informational purposes only. CPT coding is the sole responsibility of the billing party.

This testing service has not been cleared or approved by the U.S. Food and Drug Administration. Testing services may not be licensed in accordance with the laws in all countries. The availability of specific test offerings is dependent upon laboratory location.
This test is not available in your region Japan, please select your nearest laboratory to request more information.
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Test Inquiry
Test Code: D4042
Download PDF Version
General Biochemical and Molecular Requisition Form

Test Description

This test detects the number of CGG repeats in the FMR1 gene. Normal: Approximately 5-44 CGG repeats. Intermediate: Approximately 54-45 unmethylated CGG repeats. Premutation: Approximately 55-200 CGG repeats and methylation of expanded allele. Affected: Over 200 CGG repeats and methylation of expanded allele.

Condition Description

FMR1 disorders include fragile X syndrome (FXS), fragile X-associated tremor/ataxia syndrome (FXTAS), and fragile X-associated primary ovarian insufficiency (FXPOI). FXS occurs is caused from a FMR1 full mutation in affected males. Symptoms may include developmental delay, intellectual disability, autism, characteristic craniofacial features. FXTAS is caused by a FMR1 premutation. Symptoms may include a progressive cerebellar ataxia and tremor. FXPOI has been noted in 20% of women who carry a premutation allele.

Genes

FMR1

Test Methods and Limitations

DNA is amplified by the polymerase chain reaction (PCR) to determine the size of the CGG repeat region within the FMR1 gene.

Detailed Sample Requirements

DNA, Isolated
Test Details Page
Collection

Required DNA Quantity by Test Type*:

  • Next Generation Sequencing (NGS): Send >1000 ng total gDNA @ >15 ng/μL. Please ship samples in 10mM Tris. Do not use EDTA.
  • Sanger Sequencing: Send >500 ng total gDNA @ >15 ng/μL (varies by the size of the gene and the variants requested).
  • Non-Sanger Sequencing Tests: Send >500 ng total gDNA @ >15 ng/μL.
Sample Condition * Required DNA Quality: High molecular weight DNA (>12kb). A260/A280 reading should be ≥ 1.8. A260/230 a ratio range of 1.8 to 2.2. Contact the laboratory for specific amounts if total ng cannot be met.
Shipping Ship overnight at ambient temperature.
Special Sample Instructions
  • Research Laboratories: DNA extracted in research laboratories is not acceptable. Only under exceptional circumstances (e.g., proband not available) will DNA extracted in a research laboratory be accepted for clinical testing. Additional testing (e.g., of other family members) may be required to confirm results.
  • Laboratories outside the United States: Non-US laboratories are not subject to CLIA regulations and will be reviewed on a case-by-case basis. Please call to speak with a laboratory genetic counselor before submitting a DNA sample from any non-CLIA-certified laboratory.
  • Special Notes: If extracted DNA is submitted, information regarding the method used for extraction should be sent along with the sample.
Whole Blood (EDTA)
Test Details Page
Collection Container(s) EDTA (purple top)
Collection Infants (< 2-years): 2 to 3 mL; Children (>2-years): 3 to 5 mL; Older children and adults: Minimum 5mL. The blood tube should be inverted several times immediately after blood collection to prevent coagulation.
Sample Condition Store at ambient temperature. Do not refrigerate or freeze.
Shipping Ship overnight at ambient temperature ensuring receipt within 5-days of collection.
Special Sample Instructions Clotted or hemolyzed samples are not accepted.
Saliva
Test Details Page
Collection Container(s) Oragene™ Saliva Collection Kit or ORAcollect-Dx kit
Collection Collect saliva on an Oragene™ Saliva Collection Kit ORAcollect-Dx kit according to the manufacturer's instructions.
Sample Condition Store at ambient temperature. Do not refrigerate or freeze.
Shipping Ship overnight at ambient temperature.
Special Sample Instructions Please contact Revvity Omics to request the saliva collection kit for patients who cannot provide a blood sample as whole blood is the preferred sample. Testing using Saliva swabs is currently not available for customers in India. Contact the Revvity Omics laboratory for more information.
Dried Blood Spots
Test Details Page
Collection Container(s) Dried blood spot card
Collection

Follow kit instructions. Briefly, allow blood to saturate the card until indicated areas are filled and blood has soaked through the card. Air dry the card at ambient temperature for at least 3 hours.

  • NBS: Please contact Revvity Omics to request the StepOne® kit.
  • Gene Sequencing: Please contact Revvity Omics to request the DBS collection kit.
  • For pre-punched DBS: The required minimum is 6 punches
Sample Condition Follow the instructions provided with the collection set. Store the dried blood at ambient temperature for up to two days. If the specimen cannot be sent as soon as it is dry, the filter paper should be placed in a sealable plastic bag and stored in a refrigerator (≤ 8°C) or preferably in a freezer.
Shipping Follow kit instructions. Double bag and ship overnight at ambient temperature.

Resources

General Biochemical and Molecular Requisition Form