Expanding the phenotypic spectrum of pathogenic variants in the PRRT2 gene: bilateral papilledema and abducens nerve palsies secondary to pseudotumor cerebri syndrome.

An 8-year-old girl with known pathogenic variant in the PRRT2 gene causing paroxysmal kinesigenic dyskinesia with infantile convulsions presented with bilateral papilledema and abducens nerve palsy, which was subsequently confirmed to be pseudotumor cerebri syndrome (PTCS). She was treated with acetazolamide and recovered baseline vision, with some residual papilledema. PTCS is not confirmed to be associated with pathogenic variants in the PRRT2 gene; however, this case in conjunction with a previously reported case of PTCS and unilateral abducens nerve palsy in a patient with PRRT2 variants, raises the possibility that PTCS is part of the phenotypic spectrum rather than being a coincidental occurrence.