CYFIP2

Clinical Characteristics

What characteristics do patients with a change in the CYFIP2 gene have in common?
Children with CYFIP2-related neurodevelopmental disorder manifest a psychomotor development delay (a child’s delay in the acquisition of abilities such as walking or speaking), later resulting in intellectual disability (characterized by significant limitations in both intellectual functioning and in adaptive behavior).

What other health implications may be associated with a CYFIP2 gene change?
Affected children often develop epilepsy, which may be well controlled with antiepileptic drugs but unfortunately it is often difficult to find effective treatment. Often, a combination of multiple drugs is required and multiple drugs may have to be tried for a while to see their effect, since each child can react differently to them. With the onset of seizures there may be a worsening or stagnation of abilities.
The muscle tone is often lower in the whole body or the trunk, while it can be increased in the arms and legs. This is caused by impaired motor nerve control by the brain. Children with low muscle tone may have feeding difficulties, hypermobile joints, drooling and speech difficulties, decreased strength, and changes in posture.
Behavioral problems are also frequent, such as concentration difficulties or autistic features.
Head circumference is typically normal at birth, but later is smaller than that of other children of the same age. Height is usually normal.
Some children may have eye issues such as impaired visual processing in the brain or strabismus.
Some children may have sleeping difficulties.

What may a CYFIP2 gene change mean for the future of my child?
Currently we assume that children with the recurrent mutation called p.Arg87 have a severe disease course with difficult-to-treat epilepsy and severe intellectual disability. For other mutations it is not possible to predict the disease course. The degree of intellectual disability is often moderate to severe but may also be mild. This means affected people usually need at least some support as adults.

Children with a severe disease course do not learn to walk and may not be able to sit independently. They also may speak only a few words or not acquire speech. Children with a mild disease course may sit, walk and speak later than other children their age.