DEEP PHENOTYPING AND FURTHER INSIGHTS INTO ITM2B-RELATED RETINAL DYSTROPHY. Issue 4 (April 2021)

• Record Type: Journal Article
• Authors: Nassisi, Marco; Wohlschlegel, Juliette; Liu, Bingqian; Letellier, Camille; Michiels, Christelle; Aubois, Anne; Mohand-Said, Saddek; Habas, Christophe; Sahel, José-Alain; Zeitz, Christina; Audo, Isabelle
• Is Part Of: Retina. Volume 41:Issue 4(2021)
• Publication Date: 2021-04
• Subjects: ITM2B -- integral membrane protein 2B -- ITM2B-related retinal dystrophy -- retinal dystrophy with inner retinal dysfunction and ganglion cell abnormalities; Retina -- Diseases -- Periodicals; Retinal Diseases; Vitreous Body; 617.735
• DOI: 10.1097/IAE.0000000000002953
• Languages: English
• ISSNs: 0275-004X

Abstract

Abstract : Purpose: To reappraise the presentation and the course of ITM2B -related retinal dystrophy and give further insights into ITM2B expression in the retina. Methods: The clinical data of nine subjects with ITM2B -related retinal dystrophy were retrospectively reviewed. The genetic mutation was assessed for its influence on splicing in cultured fibroblasts. The cellular expression of ITM2B within the inner retina was investigated in wild-type mice through mRNA in situ hybridization. Results: All patients complained of decreased vision and mild photophobia around their twenties–thirties. The peculiar feature was the hyperreflective material on optical coherence tomography within the inner retina and the central outer nuclear layer with thinning of the retinal nerve fiber layer. Although retinal imaging revealed very mild or no changes over the years, the visual acuity slowly decreased with about one Early Treatment Diabetic Retinopathy Study letter per year. Finally, full-field electroretinography showed a mildly progressive inner retinal and cone dysfunction. ITM2B mRNA is expressed in all cellular types of the inner retina. Disease mechanism most likely involves mutant protein misfolding and/or modified protein interaction rather than misplicing. Conclusion: ITM2B -related retinal dystrophy is a peculiar, rare, slowly progressive retinal degeneration. Functional examinations (full-field electroretinography and visual acuity) seem more accurate in monitoring the progression in these patients because imaging tends to be stable over the years. Abstract : Supplemental Digital Content is Available in the Text. ITM2B -related retinal dystrophy is a progressive disease with symptoms starting in early adulthood and is characterized by retinal ganglion cell abnormalities, inner retinal, and cone dysfunctions. Functional examinations (full-field electroretinography and visual acuity) can accurately monitor the slow progression of the disease.