Spinal Dysraphism (SD)

 

Gene: NKX2-8

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: Deletion and insertion, NKX2-8 gene; c.449 del.1bp+ins.2bp, p.(A150V, fs STOP 6), exon2

Medical system: Neurological

Breeds: Weimaraner

Age of onset of symptoms: around 4 to 6 weeks

Spinal dysraphism is a genetic disease seen in the Weimaraner dog breed.  Another name for spinal dysraphism is spina bifida.  There is a developmental malformation of the neural tube and spinal cord during pregnancy, particularly in the lumbar region.  Clinical signs start appearing around 4 to 6 weeks of age as puppies become more mobile. The most common signs include moving in bunny jumps and an unusual gait; additional symptoms include abnormal reflexes, curvature of the spine, malformed sternum, abnormal hair growth on the back and kinked tails.  The disease can be mild or severe depending on where the spinal cord was affected.  The condition does not progress over time and mildly affected animals can have a more or less normal life.  The genetics of the disease in Weimaraners is said to be autosomal recessive, but this may be a simplification as there are probably additional genetic factors as well as environmental factors that contribute to the disease.

 

References:
OMIA link: [0938-9615]

Song RB, Glass EN, Kent M. (2016) Spina bifida, meningomyelocele, and meningocele. Vet Clin North Am Small Anim Pract 46:327-45. [pubmed/26725976]

Safra N, Bassuk AG, Ferguson PJ, et al. (2013) Genome-wide association mapping in dogs enables identification of the homeobox gene, NKX2-8, as a genetic component of neural tube defects in humans. PLoS Genetics 9(7):e1003646. [pubmed/23874236]