Figure 4.

Neurodegeneration in a patient harboring two heterozygous, p.A467T and p.W748S, mutations in POLG1 and secondary multiple mtDNA deletions (A) Prominent demyelination of the spinal posterior columns (Loyez stain). (B) Atrophy of the cerebellum with severe Purkinje cell and granular cell loss in the cerebellar cortex (Cresyl fast violet stain). (C) Profound complex I deficiency in remaining Purkinje cell population (anti–complex I subunit 30 kDa immunohistochemistry). Scale bar represents 100 µm.