Affected dogs have a stiff, uncoordinated gait and can turn rigid like a sawhorse resulting in falling over. Bunny hopping is commonly seen, and the affected dogs have an abnormal bark with stridor, pant more frequently than usual and excessively salivate. Muscle stiffness can improve with exercise but can worsen with cold and particularly excitement. The muscles may appear enlarged, and dental/jaw abnormalities may be noted. Dogs may also exhibit excessive panting and salivation, have an abnormal bark and loud raspy breathing, and have difficulty swallowing.
Typically, full life span
Autosomal recessive
CLCN1 and NM_001003124.2:c.803C>T
Explanation of Results
| Genotype |
Phenotype |
Interpretation |
| 2-2 (Homozygous Disease Variant) |
Unhealthy (Affected) |
Homozygous Affecteds (2-2) are expected to develop signs consistent with Myotonia Congenita 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 Myotonia Congenita 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 Myotonia Congenita and none of their offspring will inherit the disease variant allele. 1 = Normal allele; 2 = Variant allele. |
Bhalerao DP, Rajpurohit Y, Vite CH, Giger U. Detection of a genetic mutation for myotonia congenita among Miniature Schnauzers and identification of a common carrier ancestor. Am J Vet Res. 2002 Oct;63(10):1443-7. doi: 10.2460/ajvr.2002.63.1443. Erratum in: Am J Vet Res. 2003 Jan;64(1):25. PMID: 12371774.
Vite CH, Melniczek J, Patterson D, Giger U. Congenital myotonic myopathy in the miniature schnauzer: an autosomal recessive trait. J Hered. 1999 Sep-Oct;90(5):578-80. doi: 10.1093/jhered/90.5.578. PMID: 10544501.
Vite CH, Cozzi F, Rich M, Klide AK, Volk SW, Lombardo R. Myotonic myopathy in a miniature Schnauzer: case report and data suggesting abnormal chloride conductance across the muscle membrane. J Vet Intern Med. 1998 Sep-Oct;12(5):394-7. doi: 10.1111/j.1939-1676.1998.tb02141.x. PMID: 9773418.
