Persistent Leukoencephalopathy Following <scp>H</scp> 1 <scp>N</scp> 1 Infection Associated With a Novel <scp>MYRF</scp> Variant (p. <scp>G</scp> ly735 <scp>A</scp> sp)

Mutations in myelin regulatory factor (MYRF) are linked to demyelinating disorders. We report a 38-year-old male who developed acute symmetric leukoencephalopathy mimicking a stroke following an influenza A virus infection. While clinical symptoms markedly improved with corticosteroids, MRI revealed persistent white matter lesions, contrasting with the known phenotype of MYRF-related mild encephalopathy with reversible myelin vacuolization (MMERV). Genetic analysis identified a novel MYRF variant (c.2204G>A, p.Gly735Asp) in its C-terminal domain, with familial cosegregation confirming autosomal dominant inheritance. This case demonstrates that viral infections can trigger severe MYRF-related pathology and establishes persistent leukoencephalopathy as a novel clinical phenotype within the MYRF disease spectrum.