The Lesions of an Ovine Lysosomal Storage Disease. Initial Characterization

An inherited disease associated with deficiencies of beta-galactosidase and alpha-neuraminidase has been identified recently in sheep. The clinical signs, the deficiency of lysosomal enzymes, and the familial nature of the disorder suggested that the condition was a lysosomal storage disease. Four affected sheep were necropsied and their tissues were examined by histopathologic and histochemical methods to determine if the lesions were consistent with a lysosomal storage disease. Central nervous system neurons were enlarged with finely to coarsely granular cytoplasmic material, or less often, neurons were distended with multiple, variably-sized vacuoles. Loss of neurons without gliosis was evident and the Nissl substance was either dispersed and fragmented or condensed around the nuclei of remaining neurons. Neurons of intestinal and other peripheral ganglia, retinal ganglion cells, and heart Purkinje fibers were enlarged similarly. White matter of the cerebrum and spinal cord had numerous spheroid to ellipsoid axonal enlargements. Periportal hepatocytes and renal epithelial cells were enlarged with marked vacuolation. The neuronal storage material stained intensely with periodic acid-Schiff/alcian blue, with Luxol fast blue, for acid phosphatase, and moderately with oil red O stains. Renal and hepatocyte storage material stained intensely with oil red O and moderately with periodic acid-Schiff/alcian blue and Sudan black B stains. The lesions in these sheep were consistent with those of a lysosomal storage disease. Both neuronal and visceral storage occurred, but the neuronal storage was more severe.