Sir, – In order to contribute to the genotype-phenotype correlation in this rare leukodystrophy variant, we report a case of type II Alexander disease (a subset of which was previously named “adult onset” or AOAD) in a man with a rare mutation in the GFAP gene (c.382 G>A 9p.Asp128Asn). Originally described in 1949 [1], Alexander disease (AxD) is a disorder of astroglia characterized histopathologically by the presence of Rosenthal fibers on hematoxylin and eosin staining, composed of aggregates of GFAP, αB-crystallin, and HSP27 [2]. The majority of affected individuals have mutations in GFAP [3]. The classification of AxD has recently undergone revision and is currently in transition (for examples [4, 5]). Later onset (type II) patients typically present with ataxia, dysphagia, dysphonia, and a relative lack of supratentorial involvement (i.e. cognitive dysfunction, seizures) [6]. Here we present the case of a relatively older patient with AxD and describe, to our knowledge, the first neuropathologic examination in the D128N genotype.