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Fragile X syndrome (FMR1 gene)
Clinical Genetic Test
Help
offered by
Molecular Genetics and Cytogenetics, Clinical Laboratory Service
GTR Test Accession: Help GTR000568277.4
CAP
INHERITED DISEASESYNDROMIC DISEASE
Last updated in GTR: 2020-08-10
View version history
Last annual review date for the lab: 2023-07-28 LinkOut
At a Glance
Test purpose: Help
Diagnosis; Mutation Confirmation
Conditions (1): Help
Fragile X syndrome
Genes (1): Help
FMR1 (Xq27.3)
Methods (1): Help
Molecular Genetics - Targeted variant analysis: Trinucleotide repeat by PCR or Southern Blot
Target population: Help
Not provided
Clinical validity: Help
CGG-repeat-expansion full mutations account for >99% of cases of fragile …
Clinical utility: Help
Establish or confirm diagnosis
Ordering Information
Offered by: Help
Molecular Genetics and Cytogenetics, Clinical Laboratory Service
View lab's website
Test short name: Help
SXF
Specimen Source: Help
Who can order: Help
  • Licensed Physician
Test Order Code: Help
2642
Lab contact: Help
Marcela Lagos, MD, Lab Director
mlagos@med.puc.cl
+56 223548515
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.
Test service: Help
Clinical Testing/Confirmation of Mutations Identified Previously
Informed consent required: Help
Decline to answer
Pre-test genetic counseling required: Help
Decline to answer
Post-test genetic counseling required: Help
Decline to answer
Recommended fields not provided:
How to Order, Test strategy, Test development
Conditions Help
Total conditions: 1
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
* Instrument: Not provided
Clinical Information
Test purpose: Help
Diagnosis; Mutation Confirmation
Clinical validity: Help
CGG-repeat-expansion full mutations account for >99% of cases of fragile X syndrome. Therefore, tests that effectively detect and measure the CGG-repeat region of the FMR1 gene are >99% sensitive.
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.
Clinical utility: Help
Establish or confirm diagnosis
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.

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
Decline to answer.
Recommended fields not provided:
Target population, 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
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
50 patients with fragile-X Syndrome and 10 samples of CAP were analyzed using the AmplideX® kit (TP-PCR). It was possible to establish the number of CGG repeats in 100% of the cases (up to 200 repetitions). The results were compared with those obtained by Southern blot. 2 patients with mosaicism … 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, 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.