ARUP's Laboratory Test Directory

CDKL5-Related Disorders (CDKL5) Sequencing and Deletion/Duplication : 2004935
[ image for: Patient History for Rett Syndrome (MECP2) or CDKL5-Related Disorders (CDKL5) Testing]
Patient History for Rett Syndrome (MECP2) or CDKL5-Related Disorders (CDKL5) Testing
[ image for: Additional Technical Information]
Additional Technical Information


Mnemonic: CDKL5 FGA

Ordering Recommendation: Order to confirm the clinical diagnosis of a CDKL5 mutation-related disorder (eg, infantile spasm syndrome or MECP2-negative atypical Rett syndrome).
Methodology: Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification
Performed: Varies
Reported: Within 35 days
Specimen Required: Collect: Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation: Transport 3 mL whole blood. (Min: 2 mL)

Storage/Transport Temperature: Refrigerated.

Stability (collection to initiation of testing): Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Interpretive Data: Background Information for CDKL5-Related Disorders (CDKL5) Sequencing and Deletion/Duplication:
Characteristics: Vary widely but may include early onset intractable seizures, severe developmental delay, with females often exhibiting features of Rett syndrome.
Incidence: Unknown; more frequent in females than males.
Inheritance: X-linked dominant; reported cases are de novo.
Penetrance: 100 percent.
Cause: Pathogenic CDKL5 gene mutations.
Clinical Sensitivity: Approximately 17 percent in females with infantile spasms or seizures.
Methodology: Bidirectional sequencing of the CDKL5 coding region and intron-exon boundaries. Multiplex ligation-dependent probe amplification (MLPA) to detect large CDKL5 coding region deletions/duplications.
Analytical Sensitivity and Specificity of Sequencing and MLPA: 99 percent.
Limitations: Rare diagnostic errors can occur due to primer or probe site mutations. Regulatory region mutations and deep intronic mutations will not be detected. Large deletions/duplications of exon 3 will not be detected. The breakpoints of large deletions/duplications will not be determined.



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
CPT Code(s): 81406, 81479
Cross References: Atypical Rett (CDKL5-Related Disorders (CDKL5) Sequencing and Deletion/Duplication) , Epileptic Encephalopathy, Early Infantile 2 (CDKL5-Related Disorders (CDKL5) Sequencing and Deletion/Duplication) , Infantile Spasms/Atypical Rett (CDKL5-Related Disorders (CDKL5) Sequencing and Deletion/Duplication) , Rett-Like Syndrome (CDKL5-Related Disorders (CDKL5) Sequencing and Deletion/Duplication)