An Autopsy Report of Beta-Propeller Protein-Associated Neurodegeneration with 68-Year Survival, Focusing on Isoform-Specific Distribution of Hyperphosphorylated Tau.

Immunohistochemistry demonstrated widespread tau pathology.

Notably, neuronal tau inclusions contained both four-repeat (4R) and three-repeat (3R) isoforms, whereas glial tau was predominantly 4R-positive, indicating a mixed neuronal 4R/3R and glial 4R-dominant tauopathy.

Perivascular and subpial 4R-tau-dominant deposits consistent with aging-related tau astrogliopathy were also present.

LC3-positive and ferritin-positive cells suggested impaired autophagic flux, supporting the proposed autophagy-related pathogenesis of SENDA/BPAN.