Fragile X, DNA Testing
Order Code: FX
Order Form: Molecular Genetics General Consult Requisition
Specimen:
Whole Blood
Collection Medium:
Lavender top tube 3 mL (EDTA)
Minimum:
Adult minimum: 3 mL whole blood in lavender top tube (EDTA) Children minimum: 2 mL whole blood in lavender top tube (EDTA) Testing on smaller volumes than those requested will be attempted. However, in some cases, small blood volumes may compromise the ability to perform testing. Testing requires a dedicated collection tube.
Testing Schedule:
Weekly
Analytic Time:
21 days
Reference Range:
Normal: < or = to 44 CGG repeats Indeterminate: 45-55 CGG repeats Pre mutation (carrier): 56-199 CGG repeats Full mutation (affected): > or = to 200 CGG repeats
Comments:
Send blood at room temperature.
Methodology:
Polymerase Chain Reaction (PCR) and Southern Blot
Sample Processing:
Do Not Centrifuge.
Label transport tube with two patient identifiers, date and time of collection.
Patient's age and sex is required on requisition for processing.
Relevant clinical information must be submitted with specimen in order to provide correct interpretation of test results.
Submit whole blood in original container.
Sample Storage:
Room temperature for up to 24 hours, then refrigerate the whole blood if it is necessary to be held overnight, or weekends, or holidays.
Transport Instructions:
Recommend express mail or equivalent if not on courier service.
Place requisition into outside pocket of bag.
Ship at ambient temperature.
CPT Code:
83890, 83892 (x2), 83894 (x2), 83896, 83897, 83898, 83912
 
See Additional Information:
Fragile X Syndrome Information