Multimodal imaging of retinitis pigmentosa associated with Mainzer-Saldino syndrome.

Background

Syndromic ciliopathies have been variably linked to different retinal dystrophies. However, to date, few reports have characterized by means of multimodal imaging the retinal degeneration occurring in Mainzer-Saldino syndrome (MSS).

Methods

Two siblings with history of kidney disease and other systemic abnormalities presented at our eye clinic in October 2017 complaining of night blindness and visual loss. They underwent a complete ophthalmologic examination including visual acuity (VA) assessment, optical coherence tomography (OCT) and blue-light autofluorescence (BAF). A screen for inherited retinal dystrophies was performed in this occasion.

Results

At baseline, the youngest sister had slightly worse VA (20/30 vs. 20/20-25 Snellen equivalents). On fundoscopy, both siblings had severe thinning of the peripheral retina, attenuation of retinal vessels and widespread accumulation of pigmented deposits. Significant outer retinal atrophy with apparent foveal sparing was appreciable on OCT.During the 3 years of follow-up, vision remained overall stable in both patients whereas minimal progression of outer retinal atrophy was observed by means of OCT. Genetic analysis revealed compound heterozygosity in the IFT172 gene. Based on these findings, a diagnosis of retinitis pigmentosa (RP) associated with MSS was formulated.

Conclusions

Our report describes the cases of two siblings affected by retinitis pigmentosa associated with MSS. Although both carrying the same mutations and a severe RP phenotype, the youngest sister had slightly more advanced retinal degeneration highlighting the remarkable variability related to the IFT172 retinopathy.