A lethal autosomal recessive disorder associated with defective catabolism of glycoproteins due to the inherited deficiency of lysomal α-mannosidase (Burditt et al, 1978). Calves generally appear to be in poor condition and undersized. Many calves will have moderately enlarged lymph nodes throughout the body and may contain mild internal hydrocephalus. Calves seem to somewhat consistently have intracytoplasmic vacuolation lesions (Jolly et al., 1978). Two primary mutations exist, one responsible for the disorder in Galloway cattle and the other responsible for the disorder in Angus, Murray Grey, and Brangus from Australia. An additional mutation showed up in Red Angus embryos transported from Canada to Australia. These breed specific mutations may have originated in Scotland and been exported (via animals or germplasm) to America, New Zealand, and Australia. DNA testing is available and is based on the polymerase chain reaction (PCR) (Berg et al., 1997)

References
Berg, T., P. J. Healy, O. K. Tollersrud, O. Nilssen. Molecular Heterogeneity for Bovine Alpha-
Mannosidosis: PCR Based Assays for Detection of Breed – Specific Mutations. Department of
Medical Genetics. 1997. www.ncbi.gov/pubmed. Accessed June 29, 2011

Burditt, L. J., N. C. Phillips, D. Robinson, B. G. Winchester. University of London. N. S. Van-de-Water, R. D.
 Jolly. Massey University. Characterization of the Mutant α-Mannosidase in Bovine
 Mannosidosis. 1978. www.ncbi.nlm.gov. Accessed June 29, 2011.

Jolly, R. D., K. G. Thompson. The Pathology of Bovine Mannosidosis. Veterinary Pathology Online. 1978.
 http://vet.sagepub.com. Accessed June 29, 2011.