Deutsch
Hrvatski
Русский
Português
Duchenne Muscular Dystrophy (DMD) - Pembroke Welsh Corgi Type
| Acronym: | DMD |
| Gene: | DMD |
| Mutation: | g.27721607_27721608insN[(4800)] |
| Inheritance: | X-linked recessive |
| Sample type: | CHS (Cheek Swab), WBE (Whole Blood EDTA) |
| Method: |
Genetics and characteristics
Duchenne muscular dystrophy (DMD) is a genetic dystrophin-deficient lethal muscle disease identified in humans and dogs so far. Duchenne-like symptoms have been observed in more than a dozen dog breeds, but this specific type is specific to Pembroke Welsh Corgi dogs. Affected dogs show clinical signs that include generalized muscle atrophy, a stiff or shuffling gait, balance disturbance, and exercise intolerance. The disease starts to manifest at an early age, at just a few days or a week after birth and it progresses over time and may lead to death by the 3rd year. The cause of this severe type of muscular dystrophy is an insertion of a long interspersed repetitive element-1 (LINE-1) in the DMD gene coding for dystrophin. Dystrophin is a protein crucial for preserving integrity and force transmission during contraction. Muscles without dystrophin become sensitive to contraction-induced injury, undergo degeneration, and lose force production capacity.
As the DMD gene lies on the X chromosome, Duchenne muscular dystrophy found in Pembroke Welsh Corgi dogs shows an X chromosomal recessive mode of inheritance, meaning the specific mutation that causes the disease is located on the sex chromosome. Since male dogs have just one X chromosome, if they carry the mutation, they will develop a bleeding disorder. Female dogs have two X chromosomes and hence, dogs with only one copy of the mutated gene will act as carriers, and dogs carrying both mutated genes will show signs of the disease. Early genetic testing can help identify dogs that carry the gene with the specific mutation and prevent their further breeding by the proper selection of mating pairs.
Results Reported As
Test Result |
Interpretation of test result |
CLEAR |
Tested mutation was not detected in animal with „clear“ result. Animal tested as clear has wild-type allele in homozygous state (female) or hemizygous state (male) (i.e. only healthy allele on X chromosome). It will not develop disease caused by tested mutation.* It will pass only wild-type allele to its offspring. |
CARRIER |
Tested mutation was detected in animal with „carrier“ result. Animal tested as carrier has one wild-type and one mutation allele, it is in heterozygous state. It will not develop disease caused by tested mutation.* It can pass wild-type or mutation allele to its offspring. |
AFFECTED |
Tested mutation was detected in animal with „affected“ result. Animal tested as affected has mutated allele in homozygous state (female) or hemizygous state (male) (i.e. only mutated allele on X chromosome). It is likely the animal will experience a genetic disorder due to this mutation.**It will pass only mutation allele to its offspring. |
*Test excludes only tested mutation but not possible unknown mutations or factors that can lead to similar condition/symptoms.
** Penetrance of tested mutation, and potential unknown mutations or multiple other factors can possibly affect the likelihood of experiencing a genetic disorder.
References:
Hakim, C. H., Yang, H. T., Burke, M. J., Teixeira, J., Jenkins, G. J., Yang, N. N., Yao, G., Duan, D. (2021). Extensor carpi ulnaris muscle shows unexpected slow-to-fast fiber-type switch in Duchenne muscular dystrophy dogs. Disease models & mechanisms, 14(12), https://doi.org/10.1242/dmm.049006
Smith, B. F., Yue, Y., Woods, P. R., Kornegay, J. N., Shin, J. H., Williams, R. R., Duan, D. (2011). An intronic LINE-1 element insertion in the dystrophin gene aborts dystrophin expression and results in Duchenne-like muscular dystrophy in the corgi breed. Laboratory investigation; a journal of technical methods and pathology, 91(2), 216–231. https://doi.org/10.1038/labinvest.2010.146