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Fragile X Syndrome, Mol. Analysis
Clinical Genetic Test
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offered by
Mayo Clinic Laboratories
View lab's test page
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GTR Test Accession: Help GTR000593179.3
CAP
INHERITED DISEASEENDOCRINOLOGYREPRODUCTIVE HEALTH ... View more
Last updated in GTR: 2024-04-09
View version history
Last annual review date for the lab: 2023-05-30 LinkOut
At a Glance
Test purpose: Help
Diagnosis; Screening
Conditions (4): 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
Confirmation of a diagnosis of fragile X syndrome, fragile X …
Clinical validity: Help
Not provided
Clinical utility: Help
Establish or confirm diagnosis; Reproductive decision-making
Ordering Information
Offered by: Help
Mayo Clinic Laboratories
View lab's website
View lab's test page
Test short name: Help
FXS
Specimen Source: Help
Who can order: Help
  • Genetic Counselor
  • Health Care Provider
  • Licensed Dentist
  • Licensed Physician
  • Nurse Practitioner
  • Physician Assistant
  • Public Health Mandate
  • Registered Nurse
Lab contact: Help
Huong Cabral, MS, Certified Genetic counselor, CGC, Genetic Counselor
GCMolgen@mayo.edu
1-800-533-1710
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
https://www.mayocliniclabs.com/test-catalog/Specimen/35428
Order URL
Test development: Help
Test developed by laboratory (no manufacturer test name)
Informed consent required: Help
Based on applicable state law
Pre-test genetic counseling required: Help
No
Post-test genetic counseling required: Help
No
Recommended fields not provided:
Test strategy
Conditions Help
Total conditions: 4
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
Applied Biosystems 3730 capillary sequencing instrument
Targeted variant analysis
Trinucleotide repeat by PCR or Southern Blot
Applied Biosystems 3730 capillary sequencing instrument
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)
  • 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.

Target population: Help
Confirmation of a diagnosis of fragile X syndrome, fragile X tremor/ataxia syndrome, or premature ovarian insufficiency caused by expansions in the FMR1 gene Determination of carrier status for individuals with a family history of fragile X syndrome or X-linked intellectual disability Prenatal diagnosis of fragile X syndrome when there is … View more
View citations (4)
  • Fragile-X syndrome and fragile X-associated tremor/ataxia syndrome: two faces of FMR1. Jacquemont S, et al. Lancet Neurol. 2007;6(1):45-55. doi:10.1016/S1474-4422(06)70676-7. PMID: 17166801.
  • 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.
  • 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.
  • Biancalana V, Glaeser D, McQuaid S, Steinbach P. EMQN best practice guidelines for the molecular genetic testing and reporting of fragile X syndrome and other fragile X-associated disorders. Eur J Hum Genet. 2015;23(4):417-25. doi:10.1038/ejhg.2014.185. Epub 2014 Sep 17. PMID: 25227148.
Variant Interpretation:
Are family members with defined clinical status recruited to assess significance of VUS without charge? Help
Decline to answer.

Will the lab re-contact the ordering physician if variant interpretation changes? Help
No. The laboratory encourages health care providers to contact the laboratory at any time to learn how the status of a particular variant may have changed over time.
Research:
Is research allowed on the sample after clinical testing is complete? Help
Research testing is only performed under IRB approved protocol with an opt-out policy in place.
Recommended fields not provided:
Clinical validity, What is the protocol for interpreting a variation as a VUS?, Sample negative report, Sample positive report
Technical Information
Test Procedure: Help
A polymerase chain reaction (PCR)-based assay is used to detect expansions of a CGG trinucleotide tract in the 5'UTR of the FMR1 gene. Methylation status for large premutations (170+) and full mutation alleles is determined by capillary electrophoresis analysis of a PCR-amplified product from DNA that is treated with a … View more
View citations (2)
  • Grasso M, Boon EM, Filipovic-Sadic S, van Bunderen PA, Gennaro E, Cao R, Latham GJ, Hadd AG, Coviello DA. A novel methylation PCR that offers standardized determination of FMR1 methylation and CGG repeat length without southern blot analysis. J Mol Diagn. 2014;16(1):23-31. doi:10.1016/j.jmoldx.2013.09.004. Epub 2013 Oct 29. PMID: 24177047.
  • Analysis of a CGG sequence at the FMR-1 locus in fragile X families and in the general population. Snow K, et al. Am J Hum Genet. 1993;53(6):1217-28. PMID: 7902673.
Test Confirmation: Help
Positive results are confirmed when appropriate.
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
Analytical sensitivity, specificity, and accuracy are ≥ 99%.
Assay limitations: Help
For predictive testing, it is important to first document the presence of CGG-repeat amplification in the FMR1 gene in an affected family member to confirm that molecular expansion is the underlying mechanism of disease in the family. Test results should be interpreted in the context of clinical findings, family history, … 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:
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
Category: FDA exercises enforcement discretion
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.