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
CAP
INHERITED DISEASENERVOUS SYSTEMSYNDROMIC DISEASE ... View more
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
No
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
No
Post-test genetic counseling required: Help
No
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
Methodology
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
No.

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
Yes

Method used for proficiency testing: Help
Formal PT program

PT Provider: Help
College of American Pathologists, CAP
VUS:
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

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.