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Xpansion Interpreter
Clinical Genetic Test
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offered by
Asuragen Clinical Laboratory
View lab's test page
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GTR Test Accession: Help GTR000500911.8
NYS CLEP
INHERITED DISEASEENDOCRINOLOGYREPRODUCTIVE HEALTH ... View more
Last updated in GTR: 2021-11-16
View version history
Last annual review date for the lab: 2023-09-18 LinkOut
At a Glance
Test purpose: Help
Risk Assessment
Conditions (2): Help
Fragile X syndrome; Premature ovarian failure 1
Genes (1): Help
FMR1 (Xq27.3)
Methods (1): Help
Molecular Genetics - Targeted variant analysis: Trinucleotide repeat by PCR or Southern Blot
Target population: Help
Female fragile X intermediate and premutation carriers of reproductive age …
Clinical validity: Help
Not provided
Clinical utility: Help
Predictive risk information for patient and/or family members; Reproductive decision-making
Ordering Information
Offered by: Help
Asuragen Clinical Laboratory
View lab's website
View lab's test page
Test short name: Help
XI
Specimen Source: Help
Who can order: Help
  • Genetic Counselor
  • Health Care Provider
  • Licensed Physician
  • Nurse Practitioner
  • Physician Assistant
  • Registered Nurse
CPT codes: Help
**AMA CPT codes notice

Copyright: 2023 American Medical Association. All rights reserved.

Lab contact: Help
Deepa Eveleigh, MS, MB(ASCP), Scientific Director
develeigh@asuragen.com
512-681-5265
Contact Policy: Help
Laboratory can only accept contact from health care providers. Patients/families are encouraged to discuss genetic testing options with their health care provider.
How to Order: Help
Xpansion Interpreter (AGG interruption testing) is provided as a service to specific carrier screening laboratories throughout the United States. Please contact any of the following laboratories to inquire regarding XI: Progenity, Sema4, Natera, or Myriad Women's Health.
Order URL
Test service: Help
Result interpretation
    Comment: Modified risk estimates for CGG repeat instability and likelihood for expansion to fragile X full mutation upon transmission to offspring
Test development: Help
Test developed by laboratory (no manufacturer test name)
Informed consent required: Help
Based on applicable state law
Test strategy: Help
Reflex or adjunct testing for women of reproductive age identified by fragile X DNA Analysis to be fragile X intermediate or premutation carriers.
Pre-test genetic counseling required: Help
No
Post-test genetic counseling required: Help
No
Recommended fields not provided:
Test Order Code
Conditions Help
Total conditions: 2
Condition/Phenotype Identifier
Test Targets
Genes Help
Total genes: 1
Gene Associated Condition Germline or Somatic Allele (Lab-provided) Variant in NCBI
Methodology
Total methods: 1
Method Category Help
Test method Help
Instrument
Targeted variant analysis
Trinucleotide repeat by PCR or Southern Blot
Applied Biosystems 3500XL capillary sequencing instrument
Clinical Information
Test purpose: Help
Risk Assessment
Clinical utility: Help
Predictive risk information for patient and/or family members
View citations (1)
  • Yrigollen CM, Durbin-Johnson B, Gane L, Nelson DL, Hagerman R, Hagerman PJ, Tassone F, Nolin SL, Sah S, Glicksman A, Sherman SL, Allen E, Berry-Kravis E, Tassone F, Yrigollen C, Cronister A, Jodah M, Ersalesi N, Dobkin C, Brown WT, Shroff R, Latham GJ, Hadd AG. AGG interruptions within the maternal FMR1 gene reduce the risk of offspring with fragile X syndrome. Genet Med. 2012;14(8):729-36. doi:10.1038/gim.2012.34. Epub 2012 Apr 12. PMID: 22498846 l 23444167.

Reproductive decision-making
View citations (1)
  • Yrigollen CM, Durbin-Johnson B, Gane L, Nelson DL, Hagerman R, Hagerman PJ, Tassone F, Nolin SL, Sah S, Glicksman A, Sherman SL, Allen E, Berry-Kravis E, Tassone F, Yrigollen C, Cronister A, Jodah M, Ersalesi N, Dobkin C, Brown WT, Shroff R, Latham GJ, Hadd AG. AGG interruptions within the maternal FMR1 gene reduce the risk of offspring with fragile X syndrome. Genet Med. 2012;14(8):729-36. doi:10.1038/gim.2012.34. Epub 2012 Apr 12. PMID: 22498846 l 23444167.

Target population: Help
Female fragile X intermediate and premutation carriers of reproductive age and women undergoing fertility treatment
View citations (2)
  • Yrigollen CM, Durbin-Johnson B, Gane L, Nelson DL, Hagerman R, Hagerman PJ, Tassone F. AGG interruptions within the maternal FMR1 gene reduce the risk of offspring with fragile X syndrome. Genet Med. 2012;14(8):729-36. doi:10.1038/gim.2012.34. Epub 2012 Apr 12. PMID: 22498846.
  • Nolin SL, Sah S, Glicksman A, Sherman SL, Allen E, Berry-Kravis E, Tassone F, Yrigollen C, Cronister A, Jodah M, Ersalesi N, Dobkin C, Brown WT, Shroff R, Latham GJ, Hadd AG. Fragile X AGG analysis provides new risk predictions for 45-69 repeat alleles. Am J Med Genet A. 2013;161A(4):771-8. doi:10.1002/ajmg.a.35833. Epub 2013 Feb 26. PMID: 23444167.
Recommended fields not provided:
Clinical validity, What is the protocol for interpreting a variation as a VUS?, Are family members with defined clinical status recruited to assess significance of VUS without charge?, Will the lab re-contact the ordering physician if variant interpretation changes?, Is research allowed on the sample after clinical testing is complete?, Sample negative report, Sample positive report
Technical Information
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
The Xpansion Interpreter has >99% accuracy in detection of number and position of interrupting AGG repeats within the CGG trinucleotide repeat region of FMR1. In addition, this assay is capable of sizing uninterrupted CGG repeat length and/or overall CGG repeat length with precision that is within one CGG repeat.
View citations (1)
  • Yrigollen CM, Durbin-Johnson B, Gane L, Nelson DL, Hagerman R, Hagerman PJ, Tassone F, Nolin SL, Sah S, Glicksman A, Sherman SL, Allen E, Berry-Kravis E, Tassone F, Yrigollen C, Cronister A, Jodah M, Ersalesi N, Dobkin C, Brown WT, Shroff R, Latham GJ, Hadd AG. AGG interruptions within the maternal FMR1 gene reduce the risk of offspring with fragile X syndrome. Genet Med. 2012;14(8):729-36. doi:10.1038/gim.2012.34. Epub 2012 Apr 12. PMID: 22498846 l 23444167.
Proficiency testing (PT):
Is proficiency testing performed for this test? Help
Yes

Method used for proficiency testing: Help
Alternative Assessment
Recommended fields not provided:
Test Confirmation, Assay limitations, Description of internal test validation method, PT Provider, Description of PT method, Major CAP category, CAP category, CAP test list
Regulatory Approval
FDA Review: Help
Category: FDA exercises enforcement discretion
NYS CLEP Approval: Help
Number: 42392
Status: Approved
Additional Information

IMPORTANT NOTE: NIH does not independently verify information submitted to GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.