Biochemical Genetics of Glycogenosis Type II in Brahman Cattle

Glycogenosis type II is an inherited lysosomal storage disorder caused by acid α-glucosidase deficiency. The disorder is inbred in Brahman cattle, and the incidence of carriers in Australian herds averages 15%. Affected animals are lethargic and die typically in the eighth or ninth month after birth, A complete lack of acid α-glucosidase synthesis was demonstrated in cultured fibroblasts and muscle tissue of affected animals. Moreover, the tissue was found to be devoid of acid α-glucosidase mRNA. Gross abnormalities of the acid α-glucosidase gene itself were not detected by Southern blot analysis. These results suggest Brahman glycogenosis type II to be caused by a point mutation or a micro deletion/insertion in the acid α-glucosidase gene.