Congenital Myotonia

  • Congenital myotonia is a heritable neuromuscular disorder characterized by a slow relaxation of skeletal muscles following voluntary contraction that is known to occur in Nigerian Dwarf goats. Sudden muscle stiffness may cause the animal to fall over briefly.  
  • Congenital myotonia is considered an undesirable genetic disorder by ADGA. 
  • The disorder is autosomal recessive — an animal must inherit two copies of the defective gene to be affected. Carriers possessing only one copy of the gene are phenotypically normal. 
  • Test results from ADGA-approved laboratories performed prior to January 1, 2026, may be added to the ADGA database at no charge. Results must be submitted directly from the performing laboratory to performanceprograms@adga.org.
  • Results from all tests conducted on or after January 1, 2021, by the breeder or any owner of record, will be publicly accessible to all ADGA members in the NG database.
  • This testing is intended to assist ADGA members in managing their breeding programs. Test results will not affect an animal’s eligibility for registration with the Association. 
Image credit: Rebekah Rupchis