Paroxysmal dyskinesia in Soft Coated Wheaten Terriers is one of a group of hereditary movement disorders in which the recurrent episodes that do not cause a change in consciousness and vary in trigger, frequency, and duration. In Soft Coated Wheaten Terriers, the episodes of involuntary movement primarily consisting of flexion and extension of the back legs with some involvement of trunk muscles, and with involvement of the front legs as well in severe cases. These episodes can be variable in duration (from a few minutes to more than 4 hours) and frequency (from 1 episode every few days to 10 episodes per day), and no consistent trigger has been identified.
In the original study of 25 affected dogs, by Kolicheski and colleagues, 6 of the dogs were euthanized within 2 years after disease onset due to increasing severity of episodes.
Autosomal recessive
The disease-associated variant in the PIGN gene affects the binding of proteins to cells, but the precise mechanism has not been elucidated.
PIGN (phosphatidylinositol glycan anchor biosynthesis) NC_051805.1 c.398C > T p. T133I (Soft Coated Wheaten Terrier)
Genotype Phenotype Interpretation
2-2 (Homozygous Disease Variant) Unhealthy (Affected) Homozygous Affecteds (2-2) are expected to develop signs consistent with Paroxysmal Dyskinesia and all of their offspring will inherit a disease variant allele. Parents, offspring and relatives should also be tested. You may choose to contact us for a consultation on the management of this disease. 1 = Normal allele; 2 = Variant allele.
1-2 (Heterozygous) Healthy (Carrier) Heterozygous Carriers (1-2) are not expected to develop signs of Paroxysmal Dyskinesia but each of their offspring has a chance of inheriting a disease variant allele. Parents, offspring and relatives should also be tested. 1 = Normal allele; 2 = Variant allele.
1-1 (Homozygous Normal) Healthy (Normal, Clear) Homozygous Normals (1-1) are not expected to develop signs of Paroxysmal Dyskinesia and none of their offspring will inherit the disease variant allele. 1 = Normal allele; 2 = Variant allele.
Explanation of Results
Genotype |
Phenotype |
Interpretation |
2-2 (Homozygous Disease Variant) |
Unhealthy (Affected) |
Homozygous Affecteds (2-2) are expected to develop signs consistent with Paroxysmal Dyskinesia (PxD) and all of their offspring will inherit a disease variant allele. Parents, offspring and relatives should also be tested. You may choose to contact us for a consultation on the management of this disease. 1 = Normal allele; 2 = Variant allele. |
1-2 (Heterozygous) |
Healthy (Carrier) |
Heterozygous Carriers (1-2) are not expected to develop signs of Paroxysmal Dyskinesia (PxD) but each of their offspring has a chance of inheriting a disease variant allele. Parents, offspring and relatives should also be tested. 1 = Normal allele; 2 = Variant allele. |
1-1 (Homozygous Normal) |
Healthy (Normal, Clear) |
Homozygous Normals (1-1) are not expected to develop signs of Paroxysmal Dyskinesia (PxD) and none of their offspring will inherit the disease variant allele. 1 = Normal allele; 2 = Variant allele. |
Kolicheski A, Johnson GS, Mhlanga-Mutangadura T, Taylor JF, Schnabel RD, Kinoshita T, Murakami Y, is P. O’Brien DP. A homozygous PIGN missense mutation in Soft-Coated Wheaten Terriers with a canine paroxysmal dyskinesia. Neurogenetics 2017 18:39-47.
Shelton GD. Muscle pain, cramps and hypertonicity. Vet Clin North Am Small Anim Pract 2004 34:1483-1496. Pubmed: 15474685. DOI: 10.1016/j.cvsm.2004.05.019.
Cerda-Gonzalez S, Packer RA, Garosi L, Lowrie M, Mandigers PJJ, O'Brien DP, Volk HA. International veterinary canine dyskinesia task force ECVN consensus statement: Terminology and classification.2021 J Vet Intern Med 35:1218-1230. Pubmed 33769611. DOI: 10.1111/jvim.16108