We report a patient whose initial presentation in infancy resembling hereditary spastic paraplegia with extensive white matter abnormalities and residual neurological deficits was in keeping with the known history of AGS,3 as was the presence of the RNASEH2B missense mutation c.529G>A.2 However, her subsequent clinical course was highly unusual. This evidence concerns the gene RNASEH2B and Aicardi-Goutieres syndrome.