De novo in-frame deletions and duplications in the SPTAN1 gene, encoding the non-erythrocyte αII spectrin, have been associated with severe West syndrome with hypomyelination and pontocerebellar atrophy.
The major clinical features of SPTAN1 mutations include epileptic encephalopathy with hypsarrhythmia, no visual attention, acquired microcephaly, spastic quadriplegia and severe intellectual disability.
By screening SPTAN1 in 95 patients with idiopathic ID, we found a de novo in-frame mutation (p.Q2202del) in the same C-terminal domain in a patient with mild generalized epilepsy and pontocerebellar atrophy, but without IS, hypomyelination, or other brain structural defects, allowing us to define the core phenotype associated with these C-terminal SPTAN1 mutations.
Dominant-negative mutations in alpha-II spectrin cause West syndrome with severe cerebral hypomyelination, spastic quadriplegia, and developmental delay.