Introduction

CDKL5 (CDD) is a genetic disorder that is linked to the development of epilepsy in people, where early genetic screening can allow adequate treatment for those impacted by it in infancy. Currently, approximately 750 new cases of impacted individuals have been recorded for CDD, since its discovery, as an increasing number of people begin to become aware of this disorder. Diagnosis of this condition in the early stages of fetal development can aid families on decisions regarding family planning, but also permit identification of the mutations that cause CDD and thus target research for the disorder.

Causes of CDKL5 deficiency

The cause of CDKL5 is understood to be due to a mutation of the CDKL5 gene found on the X chromosome. CDKL5 gene mutation results in a faulty CDKL5 protein, which under normal conditions is necessary for brain development and function.¹ Therefore, the lack of this protein contributes to stunted brain development and thus epileptic episodes.

Despite there being no single cause for the mutation to the CDKL5 gene, the following are thought to be the potential triggers for the genetic mutation causing the development of the disorder: 

• De novo mutation
• X-linked inheritance 

CDKL5 gene mutation causes do not have any known lifestyle or environmental triggers, meaning its occurrence has been flagged down as simply being sporadic and non-specific. There is no way of curbing this mutation due to no known stimulants for the mutation.

Signs of CDKL5 deficiency

Signs of CDKL5 deficiency tend to present in areas of the body that rely on brain function to work in infants. These include:

• Early onset epilepsy 
• Motor and communication impairments²
• Severe developmental delays³
• Intellectual disability

These signs are often confused with other causes that contribute to these signs, since the symptoms of CDD tend to overlap with other neurological conditions, making its diagnosis harder. This is especially true for epilepsy, which can occur due to many other factors, like: 

• Brain damage
• Stroke 
• Inherited genetic disorders 
• Environmental influences (e.g substance abuse whilst a mother is pregnant)

Therefore, it is necessary that genetic screening can be utilised to rule out or confirm any signs that are associated with CDD deficiency, for appropriate treatment.

Challenges of diagnosing paediatric epilepsy

Epilepsy diagnosis is extremely complex because there isn’t a single diagnostic test for the condition. The diagnosis of epilepsy relies on a combination of tests, including physical examinations, patient history and neurological assessments, increasing the risk of misdiagnosis due to the diversity in ruling whether an infant has epilepsy.⁴

The role of genetic screening

Genetic screening is a tool used to analyse whether an individual’s genes highlight a mutation which predisposes them to a genetic condition or confirms its presence. In the case of CDD, genetic screening in infants can ensure early diagnosis, targeted treatment, and easy development. There is a range of genetic screening used to identify the cause of paediatric epilepsy, and these include: 

• Targeted Gene Panels 
• Whole exome sequencing⁵
• Chromosome microarray analysis⁶
• Whole genome sequencing 

Implementation of genetic screening at a younger age will ensure improved quality of life for sufferers of CDD; however, most importantly, it allows a smoother diagnosis of the cause of epilepsy without the risk of misdiagnosis. 

What parents and caregivers should know?

The key indicators of CDD in young infants are if a child is exhibiting seizures in the first few months of infancy and an overall lack of motor development, which can trigger the need for genetic screening. The best time to ask for genetic screening is when your infant is presenting these symptoms, and the tests used to diagnose the root cause of these issues fail to reveal the definitive problem. 

If you are concerned that your child may be deficient in CDKL5 and hence a sufferer of epilepsy, there are a multitude of ways you can obtain a genetic scan:

• GP referral to an epilepsy specialist
• NHS testing when there is a suspicion of a genetic condition
• Speaking to your child’s paediatrician 

It's also essential to know that these services are widely accessible and that you shouldn’t wait for your child to show more symptoms, but take advantage of these services as soon as you can.

The future of paediatric epilepsy diagnosis 

Technological advancements over the last decade have presented an exciting opportunity for advancing diagnoses of disorders like paediatric epilepsy, outside of genetic screening. With the rise of artificial intelligence (AI) across various fields like the medical industry, AI has begun to be implemented to interpret MRI scans, spotting anomalies that could typically be missed by the human eye, allowing accurate diagnosis of epilepsy.⁷

Moreover, pilot newborn screening programs are being trialled as a way to identify newborns who have an increased risk for rare and serious conditions.⁸ These programs can act as a form of preventative care post birth, minimisation of long-term complications, and inform family decisions regarding a family’s baby’s health. These programs, coupled with genetic screening, can become a powerful duo for treating and diagnosing pediatric epilepsy induced by CDKL5 deficiency.

Advocacy and awareness

Despite scientific advancements, one of the biggest barriers to diagnosis is awareness and a lack of knowledge regarding CDKL5 deficiency and pediatric epilepsy. Many paediatricians and general practitioners are not fully familiar with CDKL5 or other rare epilepsies.

Besides, raising awareness among frontline healthcare providers and educating parents on early signs (such as seizures in the first few months) is essential for timely referrals to specialists. Increased education is fundamental for recognising and taking the subsequent steps in treating paediatric epilepsy.

Support networks

Families facing a diagnosis of CDKL5 deficiency often feel isolated. Fortunately, global and national organisations are working to provide information, advocacy, and community support:

• International Foundation for CDKL5 Research (IFCR): Offers resources, updates on research, and family support
• Epilepsy Foundation: Provides education on epilepsy, patient support services, and promotes funding for research
• Genetic Alliance UK / Global Genes: Connect families affected by rare disorders and promote equity in genetic healthcare access

Together, these developments promise a future where no child’s epilepsy goes unexplained and where early diagnosis leads to better lives for children and their families.

Summary

CDKL5 Deficiency Disorder is a rare but serious genetic cause of early onset epilepsy that often presents within the first few months of life. Because symptoms can be subtle and traditional diagnostic tools may fall short, many families face a long and difficult journey before receiving a clear diagnosis. However, advances in genetic screening are transforming this landscape, allowing for earlier and more accurate identification of conditions like CDKL5. Early diagnosis opens the door to better targeted treatments, early intervention therapies, and vital support networks. With greater awareness among healthcare providers and families, more children can get the help they need sooner. Parents are encouraged to consult the doctor regarding the possibility of genetic testing if the child shows signs of unexplained seizures or developmental delays. It can lead to answers to their unanswered questions.