XSense®, Fragile X with Reflex

XSense®, Fragile X with Reflex

Test Code

16313
81243
CPT Code is subject to a Medicare Limited Coverage Policy and may require a signed ABN when ordering.
16313
81243
CPT Code is subject to a Medicare Limited Coverage Policy and may require a signed ABN when ordering.
Not offered in Quest Diagnostics Nichols Institute (IFD) – San Juan Capistrano. Please provide SERVICE AREA INFORMATION to find available tests you can order.
In-home collection is not available in your area through Quest Mobile.

Clinical Significance

XSense®, Fragile X with Reflex - Fragile X syndrome (FXS OMIM # 300624) is the most common inherited mental retardation syndrome, affecting approximately 1:4000 males and approximately 1:8000 females. The disease is caused by the expansion of a trinucleotide CGG repeat in the 5'-untranslated (UTR) region of the FMR1 gene. Methylation of the expanded CGG tract leads to silencing of expression of the FMR1 gene. The American College of Medical Genetics defines a normal repeat length as between 5 and 44. Intermediate alleles of between 45-54 repeats almost never expand to full mutations in a single meiosis. Premutation alleles are ...

Test Resources

Test FAQ

XSense, Fragile X with Reflex

Test Summary

XSense, Fragile X With Reflex

Test Details

Includes

  • If Fragile X, PCR result is not Normal, or Gray zone, then Fragile X Methylation Analysis will be performed at an additional charge (CPT codes(s): 81244)

Methodology

Polymerase Chain Reaction (PCR) with Detection by Capillary Electrophoresis

Assay Category

This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Reference Range(s)

See Laboratory Report

Alternative Name(s)

FRAX,Fragile X Syndrome (FXS),Fra(X),Fragile X with Reflex,Martin-Bell Syndrome,FMR1

LOINC® Codes, Performing Laboratory

Service Area must be determined
If Fragile X, PCR result is not Normal, or Gray zone, then Fragile X Methylation Analysis will be performed at an additional charge (CPT codes(s): 81244)

Methodology

Polymerase Chain Reaction (PCR) with Detection by Capillary Electrophoresis
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Reference Range(s)

See Laboratory Report

Alternative Name(s)

FRAX,Fragile X Syndrome (FXS),Fra(X),Fragile X with Reflex,Martin-Bell Syndrome,FMR1
Service Area must be determined

Preferred Specimen(s)

4 mL whole blood collected in an EDTA (lavender-top), ACD (yellow-top), or sodium heparin (green-top) tube

Minimum Volume

3 mL

Collection Instructions

Whole blood: Normal phlebotomy procedure. Specimen stability is crucial. Store and ship room temperature immediately. Do not freeze.

Transport Container

Original collection tube

Transport Temperature

Room temperature

Specimen Stability

  • Room temperature: 8 days
  • Refrigerated: 8 days
  • Frozen: Unacceptable

Reject Criteria

Extensive hemolysis observed • Received frozen

Setup Schedule

Service Area must be determined
4 mL whole blood collected in an EDTA (lavender-top), ACD (yellow-top), or sodium heparin (green-top) tube
3 mL
Whole blood: Normal phlebotomy procedure. Specimen stability is crucial. Store and ship room temperature immediately. Do not freeze.
Original collection tube
Room temperature
Room temperature: 8 days
Refrigerated: 8 days
Frozen: Unacceptable
Extensive hemolysis observed • Received frozen
Service Area must be determined
Not offered in Quest Diagnostics Nichols Institute (IFD) – San Juan Capistrano. Please provide SERVICE AREA INFORMATION to find available tests you can order.
In-home collection is not available in your area through Quest Mobile.
Test Details

Clinical Significance

Test Resources

Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.

The CPT codes provided are based on AMA guidance and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

This material contains content from LOINC® (http://loinc.org). The LOINC Table, LOINC Table Core are copyright © 1995-2019, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee and is available at no cost under the license at http://loinc.org/license.

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