Usher syndrome in a patient with Ellis-van Creveld syndrome

To describe a case of Ellis-van Creveld syndrome with concomitant Usher syndrome.

A 24-year-old lady with a diagnosis of Ellis-van Creveld syndrome came to our attention in 2015 complaining of nyctalopia. She underwent yearly ophthalmologic examinations, including visual acuity, dilated fundoscopy, optical coherence tomography and colour fundus photography.

On the day of her first examination, her visual acuity was 20/20, whereas fundus examination revealed diffuse peripheral retinal atrophy with pigmented bone spicules, waxy pallor of the disc and macular sparing in both eyes, compatible with retinitis pigmentosa. Due to the severe retinitis pigmentosa phenotype for the age and the concomitant neurosensory hearing loss, ancillary electrophysiological and genetic tests were requested. At the end of follow-up, visual function remained stable, with electroretinogram tests confirming the peripheral dysfunction. Interestingly, next generation sequencing test revealed a mutation in USH2A gene, suggestive of an overlapping Usher syndrome. On optical coherence tomography angiography, all plexuses appeared altered, with some degree of impairment also in the choriocapillaris of the spared macula.

Our report emphasizes the advantage of new genetic tests to investigate atypical presentations of known retinal disorders found in syndromic settings. In addition, we speculate that the underlying ciliopathy might possibly aggravate the phenotype of this case of Usher syndrome.