Rett Syndrome (MECP2), Full Gene Sequencing
0051378
Ordering Recommendation
Acceptable first-tier test for Rett syndrome. Consultation with a genetic counselor is recommended to plan the optimal MECP2 genetic testing sequence. ARUP's genetic counselors are available at 800-242-2787 x2141.
Mnemonic
RETT FGS
Methodology
Polymerase Chain Reaction/Sequencing
Performed
Varies
Reported
Within 14 days  
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
  
Collect
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).  
Specimen Preparation
Transport 3 mL whole blood. (Min: 1 mL)  
Storage/Transport Temperature
Refrigerated.  
Unacceptable Conditions
  
Remarks
  
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable  
Reference Interval
By report  
Interpretive Data
Background Information:
Characteristics:
Classic Rett Syndrome is a progressive neurodevelopmental disorder characterized by normal development until 6-18 months of age, followed by rapid developmental regression, deceleration of head growth, loss of speech and acquired motor skills, and seizures; purposeful use of hands is replaced by repetitive stereotyped hand movements. MECP2-related disorders include Rett-like Syndrome, severe congenital encephalopathy, or mild to severe mental retardation.
Incidence:
1in 10,000
Inheritance:
X-linked dominant; most cases are sporadic.
Cause:
Methyl-CpG-Binding Protein 2 (MECP2) gene mutations.
Clinical Sensitivity:
80%
Methodology:
Bidirectional sequencing of the MECP2 coding regions (exons 1-4) and intron-exon boundaries.
Analytical Sensitivity:
99%
Analytical Specificity:
99%
Limitations:
Deep intronic mutations and large deletions/duplications will not be identified. Diagnostic errors can occur due to rare sequence variations.





See Compliance Statement C: www.aruplab.com/CS
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
 
CPT Code(s)
81302
Components
Component Test Code*Component Chart NameLOINC
0051379Rett Syndrome, Full Gene Sequencing 
2001375RETT FGS Specimen 
* 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
  • MECP2 sequencing assay