DBN1

Drebrin encodes an actin cytoskeleton-organizing protein essential for dendritic spine morphogenesis, synaptic plasticity, and formation of immunological synapses. Mutations cause autosomal dominant developmental and epileptic encephalopathy with onset in infancy, characterized by severe intellectual disability, refractory seizures, and brain atrophy. This gene is highly constrained against loss-of-function variants, indicating that even single functional copies are insufficient for normal development.