Categories: Vision / eye phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 615836 (gene)

Single-gene trait/disorder: yes

Mode of inheritance: Autosomal recessive

Disease-related: yes

Key variant known: yes

Year key variant first reported: 2010

Cross-species summary: This disorder has been renamed in OMIA on the basis of the review by Miyadera et al. (2012)

Species-specific name: Progressive retinal atrophy; retinal atrophy -2

Species-specific symbol: erd; PRA-STK38L (erd) (Mowat et al., 2024) 

Molecular basis: Goldstein et al. (2010): "Fine mapping followed by candidate gene analysis of erd ... established that the disease cosegregates with a SINE insertion in exon 4 of the canine STK38L/NDR2 gene. The mutation removes exon 4 from STK38L transcripts and is predicted to remove much of the N terminus from the translated protein ... ."

Clinical features: As photoreceptor differentiation occurs postnatally in dogs (Goldstein et al., 2010), clinical signs will present from around 3-10 weeks of age. Given the affected type of photoreceptors, reduced night vision and night blindness are a common initial clinical presentation (Acland et al., 1987). Affected animals can present with poor generalised vision. Retinal degeneration will occur rapidly in the first 6 months, and then more gradually thereafter (Berta et al., 2011). Complete loss of vision will be reached at around 12-18 months of age (Acland et al., 1987). IT thanks DVM student Martina Bai, who provided the basis of this contribution in May 2023.

Pathology: Postnatal development of the photoreceptors is abnormal, with variations in morphology and function (Acland et al., 1987). Particularly, disparities are seen in the length and alignment of inner and outer segments of adjacent rods (Acland et al., 1987). Photoreceptors in affected dogs will undergo cell division and differentiate into hybrid rod/S-cone photoreceptors. Apoptosis and cell death may also occur (Berta et al., 2011). Rod and cone synapses will fail to develop correctly, eventually leading to retinal degeneration (Goldstein et al., 2010). IT thanks DVM student Martina Bai, who provided the basis of this contribution in May 2023.

Breed: Norwegian Elkhound (Dog) (VBO_0200955).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene: