Muscular dystrophy with reduced beta-sarcoglycan in a cat.

A partial beta-sarcoglycan (SG) deficiency with retention of other components of the SG complex (SGC) is described in 6-month-old, intact male domestic shorthaired kitten that was referred for evaluation of weakness, reluctance to move and dyspnoea. Neurological deficits were restricted to the neuromuscular system. Muscle biopsy revealed moderate variability in myofibre size, with numerous atrophic rounded fibres, rare myofibre necrosis, regeneration and moderate perimysial and endomysial fibrosis. Immunohistochemistry revealed decreased expression of beta- and gamma-SG and western blotting revealed markedly decreased beta-SG with normal expression of alpha-, gamma- and delta-SG, caveolin-3 and calpain-3. Sarcoglycanopathy has not previously been described in cats. In human and canine sarcoglycanopathies the deficiency in any one of the SGs leads to secondary deficiency of the entire SGC. Such spontaneously arising muscular disease in animals can provide valuable models for equivalent human disorders.