Syn: Pompe's disease

(Beef Shorthorn and Brahman cattle)

The most common clinical presentation is of progressive muscular weakness leading to collapse and inability to rise, usually, but not exclusively, after weaning. There are no pathognomonic gross necropsy findings. PAS positive cytoplasmic vacuolation of peripheral lymphocytes is indicative of the disease. Similarly, light microscopic findings of PAS positive cytoplasmic vacuolation of lymphoid tissue, liver, kidney or neurones are indicative of generalised glycogenosis.

There are three known "lethal" mutations in the acidic α-glucosidase gene in cattle, two in Brahmans (commonly known as E7 and E13) and a third in Shorthorns (commonly known as E18). The E7 mutation is the most common, with the E13 mutation restricted to descendants of one American import.

Submitters are requested to specify breed of the subject. Submitters are advised to determine (via the Australian Brahman Breeders' Association) if a Brahman subject is a descendant of the founder for the rare E13 mutation.

Diagnosis

Specimens required

See Collection of hair samples for DNA testing

(in order of preference)

Diagnosis of the disease

1. 20 to 25 hairs, with roots attached, from the distal end of the tail.
2. Lymphoid tissue and/or whole brain in buffered formalin for histopathology.

Heterozygote detection

1. 20 to 25 hairs, with roots attached, from the distal end of the tail.