Common Symptoms
L-2- hydroxyglutaric aciduria (L-2-HGA) is an inherited neurometabolic disorder affecting Yorkshire terriers. Affected dogs have a Mutation in the Enzyme that breaks down L-2-hydroxyglutaric acid resulting in increased levels of L-2-hydroxyglutaric acid in urine, blood and Cerebrospinal Fluid and progressive damage to the brain. Affected dogs typically present between four months and one year of age with symptoms of neurologic disease including “wobbly” gait, tremors, seizures, muscle stiffness with exercise or excitement and changes in behavior. In some cases, affected dogs do not present with disease until later in life.
Breed-Specific Information for the Yorkshire Terrier
The Mutation of the L2HGDH gene associated with L-2 hydroxyglutaric aciduria (Yorkshire terrier type) has been identified in the Yorkshire terrier, although its overall frequency in this breed is unknown.
Testing Tips
Genetic testing of the L2HGDH gene in the Yorkshire terrier will reliably determine whether a dog is a genetic Carrier of L-2-hydroxyglutaric aciduria (Yorkshire terrier type). L-2-hydroxyglutaric aciduria (Yorkshire terrier type) is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the L2HGDH gene mutation. Reliable genetic testing is important for determining breeding practices. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Yorkshire terriers that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
References
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Farias FH, Zeng R, Johnson GS, Shelton GD, Paquette D, O'Brien DP. A L2HGDH initiator methionine codon mutation in a Yorkshire terrier with L-2-hydroxyglutaric aciduria. BMC Vet Res. 2012 Jul 26;8:124. doi: 10.1186/1746-6148-8-124.
[PubMed: 22834903]
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Sanchez-Masian DF, Artuch R, Mascort J, Jakobs C, Salomons G, Zamora A, Casado M, Fernandez M, Recio A, Lujan A. L-2-hydroxyglutaric aciduria in two female Yorkshire terriers. J Am Anim Hosp Assoc. 2012 Sep-Oct;48(5):366-71. doi: 10.5326/JAAHA-MS-5967.
[PubMed: 22843824]
