Neurochemistry evaluated by MR spectroscopy in a patient with SPTAN1-related developmental and epileptic encephalopathy.

BACKGROUND

Mutation of the SPTAN1 gene, which encodes α-fodrin (non-erythrocyte α-II spectrin), is one of the causes of developmental and epileptic encephalopathies (DEEs). SPTAN1-related DEE is radiologically characterized by cerebral atrophy, especially due to white matter volume reduction, hypomyelination, pontocerebellar hypoplasia, and a thin corpus callosum, however, no neurochemical analysis has been reported.

CASE REPORT

A Japanese infant female presented with severe psychomotor delay, tonic spasms, and visual impairment. Whole-exome sequencing revealed a de novo variant of the SPTAN1 gene, leading to a diagnosis of SPTAN1-related DEE. MR spectroscopy at ages 5 months, 11 months, and 1 year and 4 months revealed decreased N-acetylaspartate and choline-containing compounds, and increased glutamate or glutamine.

CONCLUSION

The decreased concentrations of N-acetylaspartate and choline-containing compounds may have resulted from neuroaxonal network dysfunction and hypomyelination, respectively. The increased glutamate or glutamine may have reflected a disrupted glutamate-glutamine cycle caused by dysfunction of exocytosis, in which α-fodrin plays an important role. MR spectroscopy revealed neurochemical derangement in SPTAN1-related DEE, which may be a possible pathomechanism and will be useful for its diagnosis.