Test Details
Methodology
Polymerase chain reaction (PCR) followed by capillary electrophoresis for detection of CGG repeats, with reflex to AGG interruption analysis for CGG repeat sizes of 55-90 and methylation PCR analysis for CGG repeat sizes >149
Polymerase chain reaction (PCR) followed by capillary electrophoresis |
Polymerase chain reaction (PCR) followed by capillary electrophoresis for detection of CGG repeats, with reflex to AGG interruption analysis for CGG repeat sizes of 55-90 and methylation PCR analysis for CGG repeat sizes >149 |
Result Turnaround Time
8 - 14 days (In some cases, additional time may be required for confirmatory or reflex tests.)
8 - 14 days |
8 - 14 days (In some cases, additional time may be required for confirmatory or reflex tests.) |
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
This test is used for diagnostic testing and carrier screening for fragile X syndrome.
This test is used for |
This test is used for diagnostic testing and carrier screening for fragile X syndrome. |
Special Instructions
To test fetal specimens, including cord blood, order Fragile X Syndrome, Fetal Analysis [481718].
Limitations
Technologies used do not detect germline mosaicism and do not rule out the presence of large chromosomal aberrations including rearrangements and gene fusions, or variants in regions or genes not included in this test, or possible inter/intragenic interactions between variants, or repeat expansions. Variant classification and/or interpretation may change with time if more information becomes available. False positive or false negative results may occur for reasons that include: rare genetic variants, sex chromosome abnormalities, pseudogene interference, blood transfusions, bone marrow transplantation, somatic or tissue-specific mosaicism, mislabeled samples or erroneous representation of family relationships.
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Technologies used do not detect germline mosaicism and do not rule out the presence of large chromosomal aberrations including rearrangements and gene fusions, or variants in regions or genes not included in this test, or possible inter/intragenic interactions between variants, or repeat expansions. Variant classification and/or interpretation may change with time if more information becomes available. False positive or false negative results may occur for reasons that include: rare genetic variants, sex chromosome abnormalities, pseudogene interference, blood transfusions, bone marrow transplantation, somatic or tissue-specific mosaicism, mislabeled samples or erroneous representation of family relationships. |
Technologies used do not detect germline mosaicism and do not rule out the presence of large chromosomal aberrations including rearrangements and gene fusions, or variants in regions or genes not included in this test, or possible inter/intragenic interactions between variants, or repeat expansions. Variant classification and/or interpretation may change with time if more information becomes available. False positive or false negative results may occur for reasons that include: rare genetic variants, sex chromosome abnormalities, pseudogene interference, blood transfusions, bone marrow transplantation, somatic or tissue-specific mosaicism, mislabeled samples or erroneous representation of family relationships. This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration. |
Specimen Requirements
Specimen
Whole blood or PurFlock buccal swab kit or Oragene Dx saliva kit
Volume
4 mL whole blood or PurFlock buccal swab kit or Oragene Dx saliva kit
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4 mL whole blood or PurFlock buccal swab kit or Oragene Dx saliva kit |
Minimum Volume
3 mL whole blood or PurFlock buccal swab kit or Oragene Dx saliva kit
Container
Lavender-top (EDTA) or yellow-top (ACD-A) or pink-top (EDTA) or tan-top (EDTA) tubes, or PurFlock buccal swab kit or Oragene Dx 500 saliva collection kit
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Lavender-top (EDTA) or yellow-top (ACD-A) or pink-top (EDTA) or tan-top (EDTA) tubes, or PurFlock buccal swab kit or Oragene Dx 500 saliva collection kit |
Collection Instructions
Standard phlebotomy. Follow PurFlock buccal swab kit or Oragene Dx 500 saliva kit collection instructions. Do not eat, drink, smoke or chew gum 30 minutes prior to collection.
Stability Requirements
Whole blood: 14 days at room temperature or 30 days at 4°C
Buccal: 60 days at room temperature
Saliva: 60 days at room temperature
Storage Instructions
Maintain specimen at room temperature or refrigerate at 4°C. Do not freeze.
Causes for Rejection
Frozen or hemolyzed specimen; quantity not sufficient for analysis; improper container