Hereditary leukodystrophy described in the Standard Schnauzer, characterised by vacuolar degeneration of the white matter of the central nervous system. It produces progressive neurological signs of neonatal-juvenile onset. It is inherited in an autosomal recessive manner and is caused by a variant in the TSEN54 gene.

Standard Schnauzer (the molecular evidence corresponds to this variety; mentions of the Miniature, Medium and Giant varieties are not supported by the source of the variant). Limited data on population frequencies.

- Neonatal-juvenile onset (shortly after birth or before 4 weeks)\n- Apathy and dysphoric vocalisation\n- Hypermetric ataxia and intention tremor\n- Head tilt and circling\n- Proprioceptive deficits and spastic tetraparesis\n- Seizures and ventral strabismus in some cases

Störk et al. (2019) described a hereditary leukodystrophy in Standard Schnauzer puppies, with signs shortly after birth or before 4 weeks of age, and by linkage analysis and homozygosity mapping identified the homozygous variant TSEN54 c.371G>A p.(Gly124Asp), perfectly associated with the phenotype in 12 affected animals and about 1000 controls. The finding resolved the molecular basis of the disease.

- Monitor lines with a history of affected animals\n- Do not repeat crosses that have produced affected offspring\n- Identify carriers in at-risk lines when a genetic test is available\n- Maintain genetic diversity when replacing carrier lines\n- Exclude affected animals from breeding

Differential diagnosis with other canine leukodystrophies and demyelinating diseases and with causes of neonatal ataxia in puppies. Magnetic resonance imaging shows white matter lesions. Confirmation is molecular (TSEN54 c.371G>A). Management is supportive and the prognosis is severe.

1. Störk T et al. 2019. TSEN54 missense variant in Standard Schnauzers with leukodystrophy. PLoS Genet 15(10):e1008411. PMID: 31584937
2. OMIA:002215-9615. Leukodystrophy, TSEN54-related, perro.