Rett Syndrome (MECP2), Deletion and Duplication
0051618
 
Ordering Recommendation
This is a second tier test and REQUIRES PERMISSION fromARUPs Genetic Counselor (800-242-2787, x2141) before ordering. Preferred initial test is the sequencing and deletion/duplication test.
Mnemonic
RETTDELDUP
Methodology
Multiplex Ligation-dependent Probe Amplification
Performed
Mon, Sat
Reported
7-14 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 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.
Incidence:
1 in 10,000.
Inheritance:
X-linked dominant; most cases are sporadic.
Cause:
Methyl-CpG-Binding Protein 2 (MECP2) gene mutations.
Clinical Sensitivity:
Up to 15 percent.
Methodology:
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.
Limitations:
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 www.aruplab.com.



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

See Compliance Statement C: www.aruplab.com/CS
Note
CPT Code(s)
81304
Components
Component Test Code*Component Chart Name
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, contact interface support at interface.support@aruplab.com.
Cross References
  • MECP2 (Rett Syndrome (MECP2), Deletion and Duplication)