Muscular Dystrophy, Ullrich type

Gene: COL6A1

Transmission: Autosomal recessive

For an autosomal recessive genetic disease an animal must have two copies of the mutation in question to be at risk of developing the disease.  Both parents of an affected animal must be carriers of at least one copy of the mutation.  Animals that have only one copy of the mutation are not at risk of developing the disease but are carrier animals that can pass the mutation on to future generations.

Mutation: Substitution, COL6A1 gene; c.289 C>G , p.(E97 STOP)

Medical system: Muscular

Breeds: American Staffordshire Terrier/Amstaff, Landseer, Schnauzer - Miniature

Age of onset of symptoms: between 2 and 8 weeks.

Ullrich type muscular dystrophy is an autosomal recessive genetic disorder caused by a mutation in a collagen gene, COL6A1, associated with the Landseer dog breed.  In affected animals, muscle fibers are gradually destroyed and replaced by adipose tissue, so that muscle mass is reduced and muscle contraction strength is diminished.  Clinical signs of this disease include reluctance to move, an abnormal gait with short strides, muscle atrophy and joint contraction.  In some cases, the affected animal may lose its ability to move altogether.  Dogs suffering from this disease are normally euthanized due to welfare considerations.

It should be noted that Ullrich-type muscular dystrophy is autosomal recessive, meaning that male and female animals can be affected equally. This is to be distinguished from Duchenne muscular dystrophy, where transmission is linked to the X chromosome, and which will affect male animals preferentially while females animals (the mothers) are carriers.

References :

OMIA link: [1967-9615]

Donner J, Freyer J, Davison S, et al. (2023) Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs.  PLoS Genet. 19(2):e1010651. [pubmed/36848397]

Shelton GD, Minor KM, Friedenberg SG, et al. (2023) Current classification of canine muscular dystrophies and identification of new variants. Genes (Basel) 14(8):1557. [pubmed/37628610]

Brands J, Steffen F, Spennes J, et al. (2020) COL6A1 related muscular dystrophy in Landseer dogs – a canine model for Ullrich congenital muscular dystrophy. Muscle Nerve 63:608-616. [pubmed/33382107]

Steffen F, Bilzer T, Brands J, et al. (2015) A nonsense variant in COL6A1 in Landseer dogs with muscular dystrophy. G3 (Bethesda) 5:2611-7. [pubmed/26438297]

Contributed by: Nicolas Mathieu and Gabriel Vallée, class of 2027, Veterinary Medicine Faculty, University of Montreal.  (Translation: DWS).