CYFIP2-related developmental and epileptic encephalopathy (DEE), also known as Early Infantile Epileptic Encephalopathy (EIEE), is a rare genetic neurological disorder caused by mutations in the CYFIP2 gene. This gene plays a critical role in brain development and function, especially in synaptic signaling and cytoskeletal organization in neurons. Key features of CYFIP2 DEE include:

Early-Onset Epilepsy: Seizures usually begin in infancy, often in the first few months of life. Seizure types can include infantile spasms, tonic seizures, or focal seizures. These seizures are often resistant to treatment.

Developmental Delay and Intellectual Disability: Significant global developmental delay is typical. Most affected individuals have severe intellectual disability, limited or no speech, and delayed motor milestones (like walking).

Neurological and Behavioral Symptoms: Hypotonia (reduced muscle tone), Poor coordination, Sometimes features of autism spectrum disorder.

Genetic Cause: Usually due to de novo (new, not inherited) missense mutations in the CYFIP2 gene. These mutations affect neuronal structure and signaling by disrupting cytoskeleton dynamics and protein synthesis at synapses.

Other symptoms:  Visual impairments, Feeding difficulties and Neutropenia/Leukopenia are often reported.

Treatment: There is no cure and no approved treatments. treatment is symptomatic and supportive.

Anti-seizure medications are used, but seizures can be difficult to control.

Early intervention with physical, occupational, and speech therapies is essential.

Multidisciplinary care involving neurologists, geneticists, and other specialists may be necessary to manage the various aspects of CYFIP2 EIEE.

The outlook for individuals with CYFIP2 DEE/EIEE varies. Some may have significant developmental and intellectual disabilities, while others may show some improvement with treatment and therapy. Early intervention and supportive care play a critical role in optimizing outcomes.

The CYFIP2 gene, also known as cytoplasmic FMR1-interacting protein 2, plays a crucial role in brain development and function.

CYFIP2 interacts with the Fragile X Mental Retardation Protein (FMRP), which is essential for normal brain function. FMRP is known to be involved in the regulation of protein synthesis at synapses, the points of communication between nerve cells. CYFIP2 helps regulate this interaction and is thought to play a role in modulating synaptic activity and plasticity.

CYFIP2 is involved in the regulation of the actin cytoskeleton, a network of protein filaments and tubules that provides structural support to cells and is crucial for cell movement and shape. This regulation impacts neuronal growth and development.

By influencing the activity of FMRP and regulating actin dynamics, CYFIP2 is involved in synaptic plasticity—the ability of synapses to strengthen or weaken over time, which is essential for learning and memory.

CYFIP2 is important for proper neuronal growth and development. It affects the formation and maturation of neuronal connections and is essential for normal brain function.

CYFIP2 helps regulate the translation of specific mRNAs into proteins at the synapse, affecting the synthesis of proteins necessary for synaptic function and plasticity.

The CYFIP2 Network was established in 2023 as one mother's "behind the scenes" effort to advocate for a treatment for her son. We seek to raise awareness, and support children, families and research of CYFIP2 EIEE. Together, with a few families and scientists, we work to support the development of a treatment. You can see more about us (here). The CYFIP2 Network is a 501c3 nonprofit organization located in the United States with FEIN 93-4821164.