April 2008

Groundbreaking Test For EPSM

The discovery of a genetic test for equine polysaccharide storage myopathy will help diagnosis.

Geneticist Dr. Molly McCue at the University of Minnesota, in conjunction with Dr. James Mickelson and Dr. Stephanie Valberg of the Comparative Neuromuscular Diagnostic Laboratory, have announced the availability of a genetic test for equine polysaccharide storage myopathy (PSSM/EPSM).

They have uncovered a genetic mutation that accounts for over 90% of cases of PPSM/EPSM across all breeds. The mutation involves an enzyme involved in the manufacturing of glycogen, the storage form of glucose in muscle cells. A second mutation that they are calling the modifying gene has been identified in Quarter Horses and Quarter-Horse-related breeds. A Quarter Horse positive for both mutations will have more severe signs of the disease. …