Test Detail

Multi-disease panel for the Yorkshire Terrier that groups five tests for hereditary conditions described in the breed: prcd-PRA progressive retinal atrophy, chondrodysplasia and chondrodystrophy (CDPA and CDDY, with risk of degenerative disc disease IVDD), subacute necrotizing encephalopathy (SNE), L-2-hydroxyglutaric aciduria (L-2-HGA) and primary lens luxation (PLL). Each test reports the clear/carrier/affected status for the corresponding variant and allows matings to be planned. The panel does not replace ocular examination or clinical follow-up: PLL is late-onset and several conditions combine reproductive risk with specific clinical management.

Applicable breed: Yorkshire Terrier. L-2-HGA and PLL are documented in the breed; Yorkshire Terrier SNE is a distinct entity described by Drögemüller et al. (2020). FGF4 insertions (CDPA/CDDY) are widespread in chondrodystrophic breeds and present in small, medium and large breeds. There are no reliable carrier frequencies per breed (limited data).

- Genotype breeding animals before mating; the panel handles five conditions in a single sample\n- Recessive conditions (prcd-PRA, SNE, L-2-HGA, PLL): do not mate carrier×carrier (25 % affected homozygotes); carrier×clear produces no affected animals and yields 50 % carriers\n- CDPA/CDDY (FGF4): inform about the short-leg phenotype and the dose-dependent IVDD risk; combine with weight control and jumping management\n- After a confirmed clinical case, do not repeat the parental mating and communicate the status to the buyer

Check which variants each laboratory includes, because Yorkshire Terrier panels vary between providers. Annual ocular examination (ECVO) as a complement for PLL and prcd-PRA. L-2-HGA is confirmed by magnetic resonance imaging and elevated L-2-hydroxyglutaric acid in urine/CSF. Yorkshire Terrier SNE is due to SLC19A3 and its diagnosis is one of exclusion of other necrotizing encephalopathies. CDPA (FGF4 on CFA18) and CDDY (FGF4 on CFA12) are independent insertions; the IVDD risk linked to CDDY is modulated by weight control, exercise and orthopaedic management.

1. Zangerl B et al. Identical mutation in a novel retinal gene causes progressive rod-cone degeneration in dogs and retinitis pigmentosa in humans. Genomics. 2006;88(5):551-563. PMID: 16938425.
2. Parker HG et al. An expressed fgf4 retrogene is associated with breed-defining chondrodysplasia in domestic dogs. Science. 2009;325(5943):995-998. PMID: 19608863.
3. Brown EA et al. FGF4 retrogene on CFA12 is responsible for chondrodystrophy and intervertebral disc disease in dogs. Proc Natl Acad Sci U S A. 2017;114(43):11476-11481. PMID: 29073074.
4. Farias FH et al. A L2HGDH initiator methionine codon mutation in a Yorkshire terrier with L-2-hydroxyglutaric aciduria. BMC Vet Res. 2012;8:124. PMID: 22834903.
5. Sanchez-Masian DF et al. L-2-hydroxyglutaric aciduria in two female Yorkshire terriers. J Am Anim Hosp Assoc. 2012;48(5):366-371. PMID: 22843824.
6. Farias FH et al. An ADAMTS17 splice donor site mutation in dogs with primary lens luxation. Invest Ophthalmol Vis Sci. 2010;51(9):4716-4721. PMID: 20375329.
7. Drögemüller M et al. SLC19A3 loss-of-function variant in Yorkshire Terriers with Leigh-like subacute necrotizing encephalopathy. Genes (Basel). 2020;11(10):1215. PMID: 33081289.
8. OMIA:001298-9615 (prcd), OMIA:002542-9615 (CDPA), OMIA:002133-9615 (CDDY/SD), OMIA:001371-9615 (L-2-HGA), OMIA:000588-9615 (PLL).