Preferred initial test to confirm the clinical diagnosis of a CDKL5-related disorder in individuals with infantile seizures, X-linked infantile spasm syndrome, MECP2-negative atypical Rett syndrome, autism, or intellectual disability with seizure disorder.
Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification
Lavender (K2EDTA), Pink (K2EDTA), or Yellow (ACD Solution A or B).
Transport 3 mL whole blood. (Min: 2 mL)
Ambient: 1 Week; Refrigerated: 1 Month; Frozen: 6 Months
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: Rare; more frequent in females than males.
Inheritance: X-linked dominant; reported cases are de novo.
Penetrance: 100 percent.
Cause: Pathogenic variants in CDKL5 gene.
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: Diagnostic errors can occur due to rare sequence variations. Regulatory region and deep intronic variants will not be detected. The breakpoints of large deletions/duplications will not be determined. Single exon deletions/duplications may not be detected due to probe location.
Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|2004936||CDKL5-Related Disorder Seq,DelDup Spec||31208-2|
|2004937||CDKL5-Related Disorder Seq,DelDup Interp||48978-1|
- Atypical Rett
- Epileptic Encephalopathy, Early Infantile 2
- Infantile Spasms/Atypical Rett
- Rett-Like Syndrome