Infantile and late onset form of generalised glycogenosis type II in cattle.

A herd of cattle which produces calves with generalised glycogenosis type II has been established. Seven affected animals have been born and their disease status as indicated by a decreased acid alpha-glucosidase activity and excessive glycogen deposition in muscle, can be detected on the day of birth. Two animals have died of heart failure aged 3 and 5 months and have shown cardiomegally. Five animals were clinically normal until 9 months of age when they failed to maintain weight gain, showed muscle weakness and four were killed aged between 12 and 16 months after showing difficulty in rising. All affected animals had abnormal ECG tracings and had elevated levels of CK, LDH and HBDH in serum. Excessive amounts of glycogen were deposited in voluntary, cardiac and smooth muscle, and in cells of the nervous system. The muscles showed a vacuolar myopathy. Both the infantile and late onset forms of generalised glycogenosis type II are present in this herd of cattle. The condition appears to be controlled by a recessive allele at a single autosomal locus.