Novel CYFIP2 Frameshift Variant Linked to Dyskinetic Crises: Functional Studies Show Impaired Cell Motility.

Area of Science:

• Neuroscience
• Genetics
• Cell Biology

Background:

• CYFIP2 is crucial for actin cytoskeleton regulation.
• CYFIP2 mutations are linked to developmental and epileptic encephalopathy (DEE), neurodevelopmental issues, and movement disorders.
• Dyskinetic crises are an occasional, severe movement disorder associated with DEE.

Purpose of the Study:

• To report a novel CYFIP2 frameshift variant (c.281_282insA/p.(Gln95ProfsTer15)).
• To investigate the functional impact of this variant on cellular dynamics.
• To confirm CYFIP2's role in causing dyskinetic crises and broaden the understanding of CYFIP2-related disorders.

Main Methods:

• Clinical and genetic evaluations of a patient with DEE.
• Functional studies using patient-derived fibroblasts.
• Analysis of actin dynamics and cell motility via confocal microscopy and live-cell imaging.

Main Results:

• The patient presented with DEE, delayed neurodevelopment, refractory seizures, and movement disorders including dystonia, choreoathetosis, and dyskinetic crises.
• Functional studies demonstrated disrupted actin organization and impaired cell motility in patient fibroblasts.
• Altered protrusive structures were observed, indicating significant cellular dysfunction.

Conclusions:

• The novel CYFIP2 variant is causative for DEE and dyskinetic crises.
• CYFIP2 plays a critical role in cellular dynamics, and its dysfunction leads to a broader spectrum of neurological disorders.
• Early genetic diagnosis is vital for potential therapeutic strategies for CYFIP2-related conditions.