Rett Syndrome (MECP2), Deletion and Duplication (INACTIVE as of 05/15/17: Refer to 0051614)
Ordering Recommendation

This is a second tier diagnostic 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).

Multiplex Ligation-dependent Probe Amplification
Mon, Sat
7-14 days
New York DOH Approval Status
This test is New York DOH approved.
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B). 
Specimen Preparation
Transport 3 mL whole blood. (Min: 1 mL) 
Storage/Transport Temperature
Unacceptable Conditions
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable 
Reference Interval
By report
Interpretive Data
Background Information
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 the hands is replaced by repetitive, stereotyped hand movements. MECP2-related disorders include Rett-like Syndrome, severe congenital encephalopathy, or mild to severe mental retardation.
1 in 10,000.
X-linked dominant; most cases are sporadic.
Methyl-CpG-Binding Protein 2 (MECP2) gene mutations.
Clinical Sensitivity:
Up to 15 percent.
Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large deletions/duplications in the MECP2 coding regions (exons 1-4).
Analytical Sensitivity:
90 percent.
Analytical Specificity:
98 percent.
Breakpoints of large deletions/duplications cannot be determined; deep intronic mutations, single base pair substitutions and small deletions/duplications will not be detected; analytical sensitivity may be compromised by rare primer site mutations. Diagnostic errors can occur due to rare sequence variations.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online at

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.

Component Test Code*Component Chart NameLOINC
0051617Rett Syndrome, Deletion and Duplication
2001376RETTDELDUP 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.
  • MECP2
  • MECP2 deletion/duplication assay