| Test Code | D4042 | |
| Test Summary | This test detects the CGG repeat expansion in the FMR1 gene. |
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| Turn-Around-Time (TAT)* | 10 - 14 days | |
| Acceptable Sample Types | DNA, Isolated Dried Blood Spots Saliva Whole Blood (EDTA) |
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| Acceptable Billing Types |
Self (patient) Payment Institutional Billing
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| Self (patient) Price | $385.00 | |
| Institutional Price | $385.00 | |
| CPT Codes** | 81244 (x1) |
This test detects the number of CGG repeats in the FMR1 gene. Normal: Approximately 5-44 CGG repeats. Intermediate: Approximately 54-45 unmethylated CGG repeats. Premutation: Approximately 55-200 CGG repeats and methylation of expanded allele. Affected: Over 200 CGG repeats and methylation of expanded allele
This test may be appropriate for individuals with a clinical suspicion of a FMR1 disorder and/or family history of the condition.
FMR1 disorders include fragile X syndrome (FXS), fragile X-associated tremor/ataxia syndrome (FXTAS), and fragile X-associated primary ovarian insufficiency (FXPOI). FXS occurs is caused from a FMR1 full mutation in affected males. Symptoms may include developmental delay, intellectual disability, autism, characteristic craniofacial features. FXTAS is caused by a FMR1 premutation. Symptoms may include a progressive cerebellar ataxia and tremor. FXPOI has been noted in 20% of women who carry a premutation allele.
DNA is amplified by the polymerase chain reaction (PCR) to determine the size of the CGG repeat region within the FMR1 gene.
Required DNA Quantity by Test Type*:
- Next Generation Sequencing (NGS): Send >1000 ng total gDNA @ >15 ng/μL. Please ship samples in 10mM Tris. Do not use EDTA.
- Sanger Sequencing: Send >500 ng total gDNA @ >15 ng/μL (varies by the size of the gene and the variants requested).
- Non-Sanger Sequencing Tests: Send >500 ng total gDNA @ >15 ng/μL.
- Research Laboratories: DNA extracted in research laboratories is not acceptable. Only under exceptional circumstances (e.g., proband not available) will DNA extracted in a research laboratory be accepted for clinical testing. Additional testing (e.g., of other family members) may be required to confirm results.
- Laboratories outside the United States: Non-US laboratories are not subject to CLIA regulations and will be reviewed on a case-by-case basis. Please call to speak with a laboratory genetic counselor prior to submitting a DNA sample from any non-CLIA certified laboratory.
- Special Notes: If extracted DNA is submitted, information regarding the method used for extraction should be sent along with the sample.
Dried blood spot card
Follow kit instructions. Briefly, allow blood to saturate card until indicated areas are filled and blood has soaked through card. Air dry card at ambient temperature for at least 3 hours.
- NBS: Please contact PKIG to request the StepOne® kit.
- Gene Sequencing: Please contact PKIG to request the DBS collection kit.
- For pre-punched DBS: The required minimum 6 punches with 3.2 mm or 4 punches 4.75 mm.
Oragene™ Saliva Collection Kit or ORAcollect-Dx kit
Collect saliva on an Oragene™ Saliva Collection Kit ORAcollect-Dx kit according to the manufacturer’s instructions.
Please contact PerkinElmer to request the saliva collection kit for patients that cannot provide a blood sample as whole blood is the preferred sample.
EDTA (purple top)
Infants (< 2-years): 2 to 3 mL; Children (>2-years): 3 to 5 mL; Older children and adults: Minimum 5mL. The blood tube should be inverted several times immediately after blood collection to prevent coagulation.
Clotted or hemolyzed samples are not accepted.