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Fragile X CGG Repeat Expansion Analysis
Clinical Genetic Test
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offered by
Sanford Medical Genetics Laboratory
View lab's test page
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GTR Test Accession: Help GTR000613425.1
CAP
INHERITED DISEASESYNDROMIC DISEASEENDOCRINOLOGY ... View more
Registered in GTR: 2024-10-24
View version history
Last annual review date for the lab: 2024-10-24 LinkOut
At a Glance
Test purpose: Help
Diagnosis; Screening
Conditions (3): Help
Fragile X syndrome; Fragile X-associated tremor/ataxia syndrome; Premature ovarian failure
Genes (1): Help
FMR1 (Xq27.3)
Methods (2): Help
Molecular Genetics - Methylation analysis: Methylation-specific PCR; ...
Target population: Help
Individuals with symptoms of fragile X syndrome, fragile X tremor/ataxia …
Clinical validity: Help
Not provided
Clinical utility: Help
Establish or confirm diagnosis; Reproductive decision-making
Ordering Information
Offered by: Help
Sanford Medical Genetics Laboratory
View lab's test page
Test short name: Help
Fragile X
Specimen Source: Help
  • Peripheral (whole) blood
Who can order: Help
  • Health Care Provider
Test Order Code: Help
LBOR0123
CPT codes: Help
**AMA CPT codes notice

Copyright: 2023 American Medical Association. All rights reserved.

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
Call Sanford Client support at (605) 328-5493
Order URL
Informed consent required: Help
Based on applicable state law
Test strategy: Help
PCR and Methylation-specific PCR to determine FMR1 CGG repeat size and methylation status
Pre-test genetic counseling required: Help
Decline to answer
Post-test genetic counseling required: Help
Decline to answer
Recommended fields not provided:
Lab contact for this test, Test development
Conditions Help
Total conditions: 3
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: 2
Method Category Help
Test method Help
Instrument *
Methylation analysis
Methylation-specific PCR
Targeted variant analysis
Trinucleotide repeat by PCR or Southern Blot
* Instrument: Not provided
Clinical Information
Test purpose: Help
Diagnosis; Screening
Clinical utility: Help
Establish or confirm diagnosis
View citations (1)
  • Finucane B, Abrams L, Cronister A, Archibald AD, Bennett RL, McConkie-Rosell A. Genetic counseling and testing for FMR1 gene mutations: practice guidelines of the national society of genetic counselors. J Genet Couns. 2012;21(6):752-60. doi:10.1007/s10897-012-9524-8. Epub 2012 Jul 14. PMID: 22797890.

Reproductive decision-making
View citations (1)
  • Monaghan KG, Lyon E, Spector EB, . ACMG Standards and Guidelines for fragile X testing: a revision to the disease-specific supplements to the Standards and Guidelines for Clinical Genetics Laboratories of the American College of Medical Genetics and Genomics. Genet Med. 2013;15(7):575-86. doi:10.1038/gim.2013.61. Epub 2013 Jun 13. PMID: 23765048.

Target population: Help
Individuals with symptoms of fragile X syndrome, fragile X tremor/ataxia syndrome (FXTAS), or premature ovarian insufficiency (FXPOI); Individuals with a family history of fragile X syndrome
Recommended fields not provided:
Clinical validity, What is the protocol for interpreting a variation as a VUS?, Is research allowed on the sample after clinical testing is complete?, Sample negative report, Sample positive report
Technical Information
Test Procedure: Help
PCR is performed using genomic DNA from the submitted specimen to amplify the CGG trinucleotide repeat region in the 5'UTR of the FMR1 gene, followed by fragment sizing on an Applied Biosystems Genetic Analyzer and conversion of product size to the number of CGG repeats. If a full mutation allele … View more
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
FMR1 CGG repeat size is reported within one CGG repeat up to 70 CGG repeats, within 3 CGG repeats up to 120 repeats, and within 5% for repeats greater than 120. Alleles over 200 CGG repeats will be reported as ">200"
Assay limitations: Help
There are rare, pathogenic FMR1 genetic variants (missense changes or deletions) that can cause fragile X syndrome in 1% of cases and will not be detected by this assay. Intellectual disability attributed to expansion at other gfragile X loci are not detected by this assay. The reported sizes for large … View more
Proficiency testing (PT):
Is proficiency testing performed for this test? Help
Yes

Method used for proficiency testing: Help
Formal PT program

PT Provider: Help
American College of Medical Genetics / College of American Pathologists, ACMG/CAP
Recommended fields not provided:
Test Confirmation, Citations to support assay limitations, Description of internal test validation method, Citations for Analytical validity, Description of PT method, Major CAP category, CAP category, CAP test list
Regulatory Approval
FDA Review: Help
Not provided
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.