Alaskan Husky Encephalopathy

Alaskan Husky encephalopathy is a neurodegenerative disease caused by alterations in the SLC19A3 gene that produces a protein that transports thiamine (vitamin B1) which is essential for mitochondrial metabolism and energy supply in the brain.

Symptoms

Symptoms usually appear in the first year of life (between 7 and 11 months) in the form of ataxia and sudden seizures. Hypertonicity of the leg musculature, proprioceptive deficits, blindness and feeding difficulties may occur. Some dogs may live for months or a few years after the onset of symptoms.

Disease Management

Alaskan Husky encephalopathy has no specific treatment. Should your dog show any symptoms, you should see your veterinarian for evaluation.

Genetic basis

This disease follows an autosomal recessive mode of inheritance. Autosomal recessive inheritance means that the dog, regardless of sex, must receive two copies of the mutation or pathogenic variant to be at risk of developing the disease. Both parents of an affected dog must carry at least one copy of the mutation. Animals with only one copy of the mutation are not at increased risk of developing the disease, but may pass the mutation on to future generations. Breeding between dogs carrying genetic variants that can cause disease, even if they do not show symptoms, is not recommended.

Technical report

The SLC19A3.1 gene is expressed in the brain and spinal cord and produces a molecule that transports thiamine or vitamin B1. Thanks to the study of Vernau et al. it is known that the insertion (c.624insTTGC or c.624delinsTGCAA) and a single nucleotide change or SNP (c.625 C>A) in exon 2 of SLC19A3 could be responsible for this encephalopathy typical of the Alaskan Husky. Subsequently, another variant (a 35 bp insertion) was detected in the same exon that may cause the disease in Yorkshire Terrier and is not analyzed here.

Most affected breeds

Alaskan Husky
Yorkshire Terrier

Bibliography

Brenner O, Wakshlag JJ, Summers BA, de Lahunta A. Alaskan Husky encephalopathy--a canine neurodegenerative disorder resembling subacute necrotizing encephalomyelopathy (Leigh syndrome). Acta Neuropathol. 2000 Jul;100(1):50-62.

Vernau KM, Runstadler JA, Brown EA,et al. Genome-wide association analysis identifies a mutation in the thiamine transporter 2 (SLC19A3) gene associated with Alaskan Husky encephalopathy. PLoS One. 2013;8(3):e57195.