Caprine β-mannosidosis, an autosomal recessive defect of glycoprotein catabolism, is associated with a deficiency of tissue and plasma -mannosidase and with tissue accumulation and urinary excretion of oligosaccharides, including the trisaccharide Man(β1-4)GlcNAc(βl-4)GlcNAc and the disaccharide Man(β1-4)GlcNAc. This genetic disorder is evident at birth, with severe neurological deficits including a marked intention tremor, pendular nystagmus, ataxia and inability to stand. Major pathological characteristics described in Nubian goats in Michigan and in Anglo-Nubian goats in New South Wales include widespread cytoplasmic vacuolation in the nervous system and viscera, axonal spheroids, and severe myelin paucity in the brain but not spinal cord or peripheral nerves. Light microscopic examination revealed marked regional variation in the severity of central nervous system myelin deficits, with some brain areas showing nearly complete absence of myelin and other regions characterized by the presence of 25-50% of the control number of myelin sheaths.
