A clear prognosis of CASK gene mutations is extremely difficult to provide. There are a range of symptoms, severities and abilities of children with CASK. Due to the gene being fairly recently discovered and studied, older people with CASK gene mutation may not have been diagnosed. Therefore there is a lack of older CASK patients, not because of fatalities, but simply due to the fact they do not know they have CASK. Many patients may have been given the broad diagnosis of cerebral palsy.

Below are data collected from our international CASK family via the Facebook support group.

Please also see our page Common Issues to learn more.


Walking prognosis

Many parents will be told upon diagnosis that their child will never walk. Although not all children with CASK walk, and the journey to walking can be a difficult and long one, there is reason to have hope since a significant minority do achieve this milestone!

Figure 1: Graph to show the number of over 2’s who are able to walk unassisted (sample size = 98)



The most recent parent survey (July 2020) revealed that 78% of CASK children who are over 12 months old can sit unassisted.



All children with neurodevelopmental problems are at an increased risk of seizures. In a 2020 survey of 106 parents, 39% of all CASK children had developed epilepsy.

Fig 2: Graph to show ages at which CASK children develop epilepsy


Types of epilepsy

Infantile spasms is a very rare but serious form of epilepsy so it is unusual that it appears as the most common form of epilepsy in CASK children. It is also normally associated with occurring in the first year of life (typically between 3 and 8 months of life) but in CASK children it often occurs later, even proceeding into teenage years and beyond. Many doctors refer to the episodes as ‘epileptic spasms’ rather than ‘infantile spasms’ if the child has spasms beyond the age of two. This particular type of epilepsy can be very subtle in nature but causes brain damage very quickly and so must be treated as a medical emergency. The video below shows the typical eye movements during a cluster.

Fig 3: Graph to show incidence of epilepsy types in epileptic CASK children.

N.B. Infantile spasms are often misdiagnosed and can be diagnosed as myoclonic epilepsy. There is a likelihood that the number of infantile spasm cases is higher as a result. Infantile spasms DO NOT need to show hypsarrythmia on an EEG.

For more information on infantile spasms please see UKIST.

Please ensure your child’s doctors are aware of this data and educate yourselves on the signs of epilepsy, especially infantile spasms.



Some children struggle to feed properly, however the majority of children do not require intervention. Feeding tubes can be used to increase fluid and food intake.

Fig 4: At what age did your child get a feeding tube? (NG tube or gastronomy) (sample size = 91)


Communication prognosis

Communication seems to be the biggest hurdle for CASK children. Unfortunately only the least severe cases learn to talk and very few successfully master alternative forms of communication such as signing. All CASK children in the UK should be assigned an SLT (speech and language therapist).

Fig 5: How does your child communicate?