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Fragile X (FMR1) Screen with Reflex to Fragile X (FMR1) Diagnostic (INACTIVE as of 01/06/14. Refer to 2009033)
2001946
Ordering Recommendation
Mnemonic
FRAG X SCR
Methodology
Polymerase Chain Reaction/Fragment Analysis
Performed
Varies
Reported
7-10 days
New York DOH Approval Status
This test is New York DOH approved.
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
For buccal collection, the patient should not eat, drink, smoke, or chew gum for 30 minutes before collecting oral samples. 
Collect
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B). Or, one buccal sponge using the ORAcollect™collection kit (ARUP supply #49295
Specimen Preparation
Transport 3 mL whole blood. (Min: 3 mL); or, one buccal sponge in the ORAcollect™collection kit. 
Storage/Transport Temperature
For whole blood, ship refrigerated. For buccal sponge, ship at room temperature. 
Unacceptable Conditions
 
Remarks
Use only the ORAcollect™kit for buccal sampling. Other buccal collection devices (e.g., swab) are not acceptable for testing. 
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable 
Reference Interval
Test Number
Components
Reference Interval
Fragile X (FMR1) Mutation ScreenBy report
0040011Fragile X (FMR1) Diagnostic (INACTIVE as of 01/06/14. Refer to 2009033)By report

Interpretive Data
Background Information for Fragile X (FMR1) Screen:
Characteristics:
Fragile X syndrome, the most common heritable form of mental retardation, is characterized by moderate mental retardation in males and mild mental retardation in females, behavioral phenotype, connective tissue anomalies, and physical findings. Older male premutation carriers may develop fragile X-associated tremor/ataxia syndrome (FXTAS) characterized by progressive cerebellar ataxia and intention tremor. Female premutation carriers may develop premature ovarian insufficiency (20 percent), or rarely, FXTAS.
Incidence of Disease: 1 in 4000 males and 1 in 8000 females.
Incidence of Premutation: 1 in 1000 males and 1 in 350 females.
Inheritance: X-linked dominant.
Penetrance: Reduced in females.
Cause: CGG expansions in the 5' untranslated region of FMR1 leading to hypermethylation of the gene and inhibition of FMR1 transcription.
Full mutation:>200 CGG repeats (methylated)
Premutation: 55-200 CGG repeats (unmethylated)
Intermediate: 45-54 CGG repeats (unmethylated)
Common: 5-44 CGG repeats (unmethylated)
Clinical Sensitivity & Specificity: 99 percent for pre and full mutation alleles.
Methodology: PCR followed by capillary electrophoresis.
Analytic Sensitivity & Specificity: 99 percent.
Limitations: Rare FMR1 mutations, unrelated to trinucleotide expansion may not be detected. Precise sizing of the CGG repeats is not provided. Intermediate alleles will not be reported. Diagnostic errors can occur due to rare sequence variations.

Compliance Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test. However, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing. Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
If the screen suggests a pre or full mutation, then Fragile X (FMR1) Diagnostic will be added for analysis of sizing and methylation. Additional charges apply.
CPT Code(s)
81243
If reflexed, add 81244
Components
Component Test Code*Component Chart NameLOINC
2001947Fragile X Screen, Specimen31208-2
2001948Fragile X Screen, Symptoms56831-1
2001949Fragile X Screen, Family History10157-6
2001950Fragile X Screen Interpretation36913-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • FMR1 screen
  • Fragile X tremor ataxia syndrome
  • FXTAS
  • Inherited Mental Retardation
  • Martin-Bell Syndrome