Bovine beta-mannosidase deficiency.

A fatal inherited glycoprotein storage disorder is described in Salers cattle which affects both sexes. Affected calves are unable to stand at birth, have a marked intention tremor, markedly enlarged kidneys, decreased white matter in all areas of the brain, and cytoplasmic vacuolation in multiple cell types of multiple tissues with nervous, renal, lymphoid and thyroid tissues most severely affected. Affected calves were grossly deficient in lymphocyte and brain beta-mannosidase activity and had markedly reduced but not deficient activity in liver and kidney. A test mating of obligate carriers produced three genotypes: affected, carrier, non-carrier in essentially the expected ratio of 1:2:1, consistent with autosomal recessive inheritance.