R.A. Packer is presently affiliated with the Department of Veterinary Clinical Sciences, and Department of Basic Medical Sciences, Purdue University, West Lafayette, IN. This work was performed at the University of Missouri—Columbia, and was a collaborative effort between the Department of Veterinary Medicine and Surgery, the Department of Veterinary Pathobiology, and the Division of Animal Sciences. This work was previously presented as an oral abstract at the 24th Annual Forum of the American College of Veterinary Internal Medicine: Characterization and mode of inheritance of an episodic dyskinesia in the Chinook dog. 24th Annual Forum of the American College of Veterinary Internal Medicine, Louisville, KY. Journal of Veterinary Internal Medicine 2006; 20(734). Abstract 87. Oral Presentation.
Characterization and Mode of Inheritance of a Paroxysmal Dyskinesia in Chinook Dogs
Article first published online: 3 NOV 2010
Copyright © 2010 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 24, Issue 6, pages 1305–1313, November/December 2010
How to Cite
Packer, R.A., Patterson, E.E., Taylor, J.F., Coates, J.R., Schnabel, R.D. and O'Brien, D.P. (2010), Characterization and Mode of Inheritance of a Paroxysmal Dyskinesia in Chinook Dogs. Journal of Veterinary Internal Medicine, 24: 1305–1313. doi: 10.1111/j.1939-1676.2010.0629.x
- Issue published online: 3 NOV 2010
- Article first published online: 3 NOV 2010
- Submitted April 11, 2010; Revised August 3, 2010; Accepted September 13, 2010.
- Basal nuclei;
- Movement disorder;
- Muscle membrane;
Background: Paroxysmal dyskinesias are episodes of abnormal, involuntary movement or muscle tone, distinguished from seizures by the character of the episode and lack of seizure activity on ictal EEG.
Hypothesis: Paroxysmal dyskinesia is an inherited, autosomal recessive disorder in Chinook dogs.
Animals: Families of Chinook dogs with paroxysmal dyskinesia.
Methods: Pedigrees and medical histories were reviewed for 299 Chinook dogs. A family of 51 dogs was used for analysis. Episodes were classified as seizures, paroxysmal dyskinesia, or unknown, and segregation analysis was performed.
Results: Paroxysmal dyskinesia was identified in 16 of 51 dogs and characterized by an inability to stand or ambulate, head tremors, and involuntary flexion of 1 or multiple limbs, without autonomic signs or loss of consciousness. Episode duration varied from minutes to an hour. Inter-ictal EEGs recorded on 2 dogs with dyskinesia were normal. Three dogs with dyskinesia also had generalized tonic-clonic seizures. One of 51 dogs had episodes of undetermined type. Phenotype was unknown for 6 of 51 dogs, and 28 dogs were unaffected. Segregation was consistent with an autosomal recessive trait.
Conclusions and Clinical Importance: This movement disorder is prevalent in the Chinook breed, and consistent with a partially penetrant autosomal recessive or polygenic trait. Insufficient evidence exists for definitive localization; episodes may be of basal nuclear origin, but atypical seizures and muscle membrane disorders remain possible etiologies. The generalized seizures may be a variant phenotype of the same mutation that results in dyskinesia, or the 2 syndromes may be independent.