Short answer · Medically reviewed summary · Last updated: 2026-05-08
CDKL5 deficiency disorder is currently classified under the ICD-10 code G40.42 (Cyclin-dependent kinase-like 5 deficiency disorder), which was specifically assigned in 2020 to improve diagnostic tracking. Prior to the adoption of this specific code, CDKL5 was often categorized under broader codes such as G40.89 or G40.4, and it does not have a unique, dedicated ICD-9 code, as it was historically grouped under "Other epilepsies" (ICD-9 345.8). What is the clinical significance of the CDKL5 ICD-10 code? The assignment of the specific ICD-10 code G40.42 for CDKL5 is a significant milestone for the community, as it allows clinicians and researchers to more accurately track the prevalence and healthcare utilization of CDKL5 deficiency disorder.
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ICD10 code of CDKL5 and ICD9 code
ICD-10 and ICD-9 codes for CDKL5, with classification details for clinicians, coders and patients.
CDKL5 deficiency disorder is currently classified under the ICD-10 code G40.42 (Cyclin-dependent kinase-like 5 deficiency disorder), which was specifically assigned in 2020 to improve diagnostic tracking. Prior to the adoption of this specific code, CDKL5 was often categorized under broader codes such as G40.89 or G40.4, and it does not have a unique, dedicated ICD-9 code, as it was historically grouped under "Other epilepsies" (ICD-9 345.8).
What is the clinical significance of the CDKL5 ICD-10 code?
The assignment of the specific ICD-10 code G40.42 for CDKL5 is a significant milestone for the community, as it allows clinicians and researchers to more accurately track the prevalence and healthcare utilization of CDKL5 deficiency disorder. Previously, the lack of a unique code meant that patients with CDKL5 were often lost in larger datasets, making it difficult to advocate for dedicated resources or clinical research funding.
How is CDKL5 deficiency diagnosed?
Diagnosis of CDKL5 is confirmed through genetic testing that identifies a pathogenic variant in the CDKL5 gene located on the X chromosome. Because symptoms like early-onset seizures and developmental delays overlap with other conditions, clinicians look for specific clinical markers:
- Onset of seizures within the first three months of life.
- Severe global developmental delay and intellectual disability.
- Hypotonia (low muscle tone) and cortical visual impairment.
- Specific movement patterns, including repetitive hand stereotypies.
Is CDKL5 hereditary?
In the vast majority of cases, CDKL5 deficiency disorder occurs as a de novo (spontaneous) genetic mutation, meaning it is not inherited from either parent. While the CDKL5 gene is located on the X chromosome, the mutation typically happens during the formation of reproductive cells or early embryonic development. Genetic counseling is strongly recommended for families to discuss the extremely low recurrence risk for future pregnancies.
Next steps
- Consult a pediatric neurologist or a clinical geneticist to confirm your CDKL5 diagnosis and management plan.
- Connect with the 71 members of our CDKL5 community on DiseaseMaps.org to share experiences and coping strategies.
- Register with the International CDKL5 Disorder Database to contribute to global research efforts.
Medical disclaimer: This content is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment; always consult with your healthcare provider regarding your specific medical condition.
References
- NIH Genetic and Rare Diseases Information Center (GARD): CDKL5 Deficiency Disorder.
- Orphanet: CDKL5 deficiency disorder (ORPHA:369871).
- OMIM (Online Mendelian Inheritance in Man): Entry #300672.
- International Foundation for CDKL5 Research (IFCR).
Posted May 23, 2017 by Beth Ann 2120
