Background Spinocerebellar ataxia type 1 (SCA‐ATXN1) is an inherited progressive ataxia disorder characterized by an adult‐onset cerebellar syndrome combined with nonataxia signs. Retinal or optic nerve affection are not systematically described. Objectives To describe a retinal phenotype and its functional relevance in SCA‐ATXN1. Methods We applied optical coherence tomography (OCT) in 20 index cases with SCA‐ATXN1 and 22 healthy controls (HCs), investigating qualitative changes and quantifying the peripapillary retinal nerve fiber layer (pRNFL) thickness and combined ganglion cell and inner plexiform layer (GCIP) volume as markers of optic atrophy and outer retinal layers as markers of maculopathy. Visual function was assessed by high‐ (HC‐VA) and low‐contrast visual acuity (LC‐VA) and the Hardy‐Rand‐Rittler pseudoisochromatic test for color vision. Results Five patients (25%) showed distinct maculopathies in the ellipsoid zone (EZ). Furthermore, pRNFL ( P < 0.001) and GCIP ( P = 0.002) were reduced in patients (pRNFL, 80.86 ± 9.49 μm; GCIP, 1.84 ± 0.16 mm 3 ) compared with HCs (pRNFL, 97.02 ± 8.34 μm; GCIP, 1.98 ± 0.12 mm 3 ). Outer macular layers were similar between groups, but reduced in patients with maculopathies. HC‐VA ( P = 0.002) and LC‐VA ( P < 0.001) were reduced in patients (HC‐VA [logMAR]: 0.01 ± 010; LC‐VA [logMAR]: 0.44 ± 0.16) compared with HCs (HC‐VA [logMAR]: –0.12 ± 0.08; LC‐VA [logMAR]: 0.25 ± 0.05). Color vision was abnormal in 2 patients with maculopathies. Conclusions A distinct maculopathy, termed EZ disruption, as well as optic atrophy add to the known nonataxia features in SCA‐ATXN1. Whereas optic atrophy may be understood as part of a widespread neurodegeneration, EZ disruption may be explained by effects of ataxin‐1 gene or protein on photoreceptors. Our findings extend the spectrum of nonataxia signs in SCA‐ATXN1 with potential relevance for diagnosis and monitoring.

Multiple skin nodules, with histological features of adnexal tumours consistent with trichoepithelioma, were observed on the head and trunk of Syrian hamsters. Skin biopsies from 20 hamsters from five different colonies were affected, and two of the affected hamsters also had lymphoma. Two owners reported that 16 of 70 hamsters and 50 of 100 hamsters in their colonies had similar skin lesions. These tumours have previously been associated in laboratory colonies with hamster polyomavirus (HaPV) infection. Examination of skin tissues by electron microscopy failed to reveal intranuclear virus particles. Using recombinant major capsid protein VP1 of HaPV, VP1-specific antibodies were detected in sera from 12 of 12 affected hamsters and in four of four unaffected in-contact hamsters, by ELISA. The ELISA data were verified by immunoblot analysis. Eleven of 13 serum samples contained antibodies which reacted with at least one recombinant structural HaPV protein (VP2), including samples from three in-contact unaffected hamsters. Nine of the 11 anti-VP2-positive samples also reacted with recombinant VP3 of HaPV, and six reacted with VP1. Amplification by PCR and sequencing detected VP1 -encoding sequences showing a high degree of homology with HaPV. The findings suggest a possible infection by HaPV or a HaPV-like virus and it is likely that such an infection was enzootic within the affected colonies.