Muscular dystrophy with reduced beta-sarcoglycan in a cat

Area of Science:

• Veterinary Neurology
• Muscle Biology
• Genetics

Background:

• Sarcoglycanopathies are a group of muscular dystrophies characterized by defects in the sarcoglycan-cadherin complex.
• These conditions have been documented in humans and canines, impacting muscle function and integrity.
• The genetic basis and clinical presentation of sarcoglycanopathies vary, leading to diverse phenotypes.

Purpose of the Study:

• To describe a novel case of sarcoglycanopathy in a domestic shorthaired kitten.
• To investigate the molecular basis of the observed muscle weakness and neurological deficits.
• To establish a potential animal model for human sarcoglycanopathies.

Main Methods:

• Clinical evaluation of a kitten presenting with weakness and reluctance to move.
• Neurological examination to assess deficits.
• Muscle biopsy for histopathological and immunohistochemical analysis.
• Western blotting to quantify protein expression of sarcoglycan components and associated proteins.

Main Results:

• A 6-month-old male domestic shorthaired kitten exhibited progressive weakness, reluctance to move, and dyspnea.
• Neuromuscular deficits were identified.
• Muscle biopsy showed myofiber atrophy, fibrosis, and immunohistochemistry revealed decreased beta- and gamma-sarcoglycan expression.
• Western blotting confirmed a marked decrease in beta-sarcoglycan with normal levels of other sarcoglycan subunits, caveolin-3, and calpain-3.

Conclusions:

• This study reports the first case of sarcoglycanopathy in cats, characterized by a partial beta-sarcoglycan deficiency.
• The findings suggest that feline sarcoglycanopathy shares similarities with human and canine forms, potentially involving secondary deficiencies in the sarcoglycan complex.
• This feline model offers valuable insights into the pathogenesis of sarcoglycanopathies and their potential as models for human muscular dystrophies.