Fragile X Syndrome, Repeat Number Analysis with Reflex to Methylation … see more Fragile X Syndrome, Repeat Number Analysis with Reflex to Methylation Analysis  see less
GTR Test Accession: Help GTR000593816.3
Last updated in GTR: 2021-08-24
Last annual review date for the lab: 2023-07-14 LinkOut
At a Glance
Diagnosis; Pre-symptomatic; Risk Assessment; ...
Autism spectrum disorder; Cerebellar ataxia; Fragile X syndrome; ...
Genes (1): Help
FMR1 (Xq27.3)
Molecular Genetics - Methylation analysis: Methylation-specific PCR; ...
Individuals with clinical features overlapping with Fragile X syndrome (e.g. …
This assay will detect the CGG trinucleotide expansion in >99% …
Establish or confirm diagnosis; Reproductive decision-making
Ordering Information
Offered by: Help
Institute for Genomic Medicine (IGM) Clinical Laboratory
View lab's website
View lab's test page
Test short name: Help
Fragile X
Specimen Source: Help
Who can order: Help
  • Genetic Counselor
  • Health Care Provider
  • Licensed Physician
  • Nurse Practitioner
Test Order Code: Help
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
Samples can be accepted 7 days a week (Monday - Sunday). All samples must be labeled with minimum of two patient identifying information (e.g. Patient Name and Date of Birth). Please submit all samples with a completed test requisition form.
Order URL
Test development: Help
Manufactured (research use only; not FDA-reviewed)
Informed consent required: Help
Test strategy: Help
PCR analysis will be performed to evaluate the number of CGG repeats. For diagnostic testing, if a premutation (55-200 repeats) or a full mutation (>200 repeats) is detected by PCR, then reflex to methylation analysis will be automatically performed.
Pre-test genetic counseling required: Help
Post-test genetic counseling required: Help
Recommended fields not provided:
Conditions Help
Total conditions: 6
Condition/Phenotype Identifier
Test Targets
Genes Help
Total genes: 1
Gene Associated Condition Germline or Somatic Allele (Lab-provided) Variant in NCBI
Total methods: 2
Method Category Help
Test method Help
Instrument *
Methylation analysis
Methylation-specific PCR
Targeted variant analysis
Tetra-nucleotide repeat by PCR or Southern Blot
* Instrument: Not provided
Clinical Information
Test purpose: Help
Diagnosis; Pre-symptomatic; Risk Assessment; Screening
Clinical validity: Help
This assay will detect the CGG trinucleotide expansion in >99% of individuals with Fragile X syndrome and other FMR1-related disorders.
View citations (2)
Clinical utility: Help
Establish or confirm diagnosis
View citations (2)

Reproductive decision-making
View citations (2)

Target population: Help
Individuals with clinical features overlapping with Fragile X syndrome (e.g. intellectual disability, autism spectrum disorder, etc.) or other FMR-1 related disorders (e.g. late onset progressive cerebellar ataxia, intention tremor, premature ovarian failure, etc.).
Variant Interpretation:
What is the protocol for interpreting a variation as a VUS? Help
VUS and novel variants will be interpreted by trained variant analysis team member and a lab director using the current ACMG variant classification criteria.

Are family members with defined clinical status recruited to assess significance of VUS without charge? Help

Will the lab re-contact the ordering physician if variant interpretation changes? Help
Yes. No systemic re-evaluation of previously reported variants/findings are currently performed. However, if the same variant/finding is identified in another patient and current assessment results in change in variant classification/interpretation, then the laboratory will recontact the ordering provider and issue an updated report.
Recommended fields not provided:
Technical Information
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
Analytical Sensitivity >99%. Analytical Specificity >99%. Accuracy/Precision >99%.
Proficiency testing (PT):
Is proficiency testing performed for this test? Help

Method used for proficiency testing: Help
Formal PT program

PT Provider: Help
College of American Pathologists, CAP
Laboratory's policy on reporting novel variations Help
Unusual or clinically significant novel variants will be communicated to the ordering provider via telephone call or email communication.
Recommended fields not provided:
Regulatory Approval
FDA Review: Help
Category: Not Applicable
Additional Information

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