A mass screening programme of angus cattle for the mannosidosis genotype — A prototype programme for control of inherited diseases in animals

Abstract

Extract

Recent research has shown that the gene frequency for mannosidosis (pseudolipidosis) may approximate 0.05 in pedigree Angus herds (Jolly, unpublished data). As epidemiological studies suggest an equal frequency in commercial non-pedigree herds, the disease is elf economic importance to the national beef industry. Mannosidosis is an inherited lysosomal storage disease associated with a defect in catabolism, of the heterosaccharide fractioln of glycoproteins (Whittem and Walker, 1957; Jolly 1971; Hocking et al., 1972; Phillips et al., 1974). Whereas animals with mannosidosis have negligible tissue sand plasma levels of α-mannosidase, heterozygotes having one normal gene and one defective gene have approximately half the normal level of enzyme in their tissues and plasma. This observation forms the basis for a control programme in which heterozygotes are identified by their plasma α-mannosidase 1evels (Jolly et al., 1973, 1974a, b).