Beginning November 18, the American Paint Horse Association (APHA) Genetic Health Panel will include testing for myosin weighty chain myopathy (MYHM) at APHA partner laboratories. There is no additional charge for the MYHM test (as of this date) when you purchase the APHA Genetic Health Panel through UC-Davis or the APHA Panel from Etalon Diagnostics.
About MYHM
MYHM is an autoimmune disease that can cause severe, rapid muscle loss. A single dominant variant results in susceptibility to two diseases: immune-mediated myositis and non-exercise rhabdomyolysis. Horses with one or two copies of the MYHM variant are prone to rapid muscle loss, muscle weakness, stiffness, or muscle tightness.
Learn more about MYHM and other conditions online in the Genetic Health Panel and the Chrome-O-Some Compendium on horseIQ.com, APHA's interactive online learning platform.
Frequently asked questions about testing
The addition of MYHM to the testing offering will occur automatically starting November 18, 2024. Tests ordered before this date will not include MYHM, but it can be added to the existing pattern for a tiny fee.
Results for MYHM will be recorded at the APHA and printed on the horse's official registration certificate if provided when a certificate is issued.
The Genetic Health Panel requirements for breeding stallions remain unchanged. All breeding stallions (APHA, AQHA and Jockey Club) must be tested for HYPP, HERDA, GBED, MH, PSSM1 and OLWS. No additional test for MYHM is required for breeding stallion compliance.
Order DNA testing for your color at PHcentral.com or etalondx.com.
