The chromosome 16q-linked autosomal dominant cerebellar ataxia (16q-ADCA): A newly identified degenerative ataxia in Japan showing peculiar morphological changes of the Purkinje cell: The 50th Anniversary of Japanese Society of Neuropathology.

The chromosome 16q22.1-linked autosomal-dominant cerebellar ataxia (16q-ADCA) is a form of spinocerebellar ataxia (SCA) common in Japan. It is clinically characterized by late-onset purely cerebellar ataxia. The neuropathologic hallmark of 16q-ADCA is degeneration of Purkinje cells accompanied by an eosinophilic structure which we named "halo-like amorphous materials". By immunohistochemistry and electron microscopy, the structure has been so far found to contain two components: the somatic sprouts from the Purkinje cells and presynaptic terminals of unknown origin. As far as we are aware, this peculiar morphological change of Purkinje cells has not been previously described. Further investigations may disclose unique pathological processes in SCA.