CDKL5-Related Disorders (CDKL5) Sequencing
Ordering Recommendation

Confirm the clinical diagnosis of a CDKL5-related disorder (eg, infantile spasm syndrome or MECP2-negative atypical Rett syndrome).

Polymerase Chain Reaction/Sequencing
21-28 days
New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
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
Interpretive Data
Background Information for CDKL5-Related Disorders (CDKL5) Sequencing:
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/seizures.
Methodology: Bidirectional sequencing of theCDKL5 coding region and intron-exon boundaries.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations, and large deletions/duplications will not be detected.

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
2004932CDKL5-Related Disorders Seq Specimen
2004933CDKL5-Related Disorders Seq Interp
* 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.
  • Atypical Rett
  • Epileptic Encehpalopathy, Early Infantile 2
  • Infantile Spasms/Atypical Rett
  • Rett-like Syndrome