Congenital Myotonia (CM)
Fainting Goats, Nervous Goats, Wooden-Leg Goats, Scare Goats, Tennessee Fainting Goats, Congenital Myotonia (CM) in Goats
Congenital myotonia (CM) is a genetic neuromuscular disorder that is caused by diminished chloride conductance in the muscle cell membrane. Symptoms of the disease are characterized by a slow relaxation of skeletal muscles following voluntary contraction. Animals affected by the disorder will exhibit sudden muscle stiffness when excited or startled. This stiffness often causes the animal to fall over for a brief period of time and has led to the common name “fainting” goats.
Reading Your Results
A. (CLEAR/NORMAL):
These goats have two copies of the normal gene and will neither develop Congenital Myotonia nor pass this mutation to their offspring.
B. (CARRIER/NOT AFFECTED):
These goats have one copy of the normal gene and one copy of the mutation associated with this disease. They will not develop Congenital Myotonia but will, if bred, pass the mutation to 50% of its offspring, on average.
C. (AT RISK/AFFECTED):
These goats have two copies of the mutation associated with Congenital Myotonia which results in a slow relaxation of skeletal muscle following voluntary contraction.
Additional Details
Inheritances
Autosomal Recessive
Affected gene
gClC-1
Chromosome
Ch. 4
Mutation
c.2656: G>C; p.Ala885Pro
Publication:
Beck, C. L., Fahlke, C., & George, A. L., Jr (1996). Molecular basis for decreased muscle chloride conductance in the myotonic goat. Proceedings of the National Academy of Sciences of the United States of America, 93(20), 11248–11252. [PubMed: 8855341].
