A Japanese case with Nasu-Hakola disease of DAP12 gene mutation exhibiting precuneus hypoperfusion.

A 38-year-old Japanese man with Nasu-Hakola disease (NHD) had repeated pathological fractures and frontal lobe symptoms which developed when he was 18 and 26 years old, respectively. Neuropsychological testing showed memory impairment, and in particular, visuo-spatial memory at the age of 35. Furthermore, single-photon emission computed tomography revealed precuneus hypoperfusion. The patient later suffered prolonged convulsive seizures, which left him in a persistent vegetative state. Genetic testing confirmed a heterozygous mutation in the DAP12 gene (a single-base deletion of 141 G in exon 3) specific to NHD. Precuneus dysfunction might contribute to characteristic memory impairment of NHD.