Gene Therapy Approaches to a Rare Retinal Disease: Choroideremia
A 28-year-old man reported reduced night vision and dark adaption since childhood, progressive visual field defects, glare, and at presentation, best-corrected visual acuity was reduced to 0.63 (ETDRS) in both eyes. Funduscopy revealed in both eyes a pale fundus with chorioretinal atrophy leading to exposure of the sclera and large choroidal vessels, widespread pigment clumping and a central island of relatively preserved retina. These clinical findings pointed to choroideremia, which was confirmed by multimodal retinal imaging, electrophysiological testing, and genetic testing. Choroideremia is a rare X-linked recessive retinal degeneration caused by mutations in the CHM gene. Comprehensive clinical characterization including molecular genetic testing is essential whenever choroideremia is suspected. Recent advances in the treatment of choroideremia include in vivo gene augmentation therapy. The disease is well suited for gene therapy approaches due to, amongst other factors, the accessibility of the eye and a large therapeutic window, with often early diagnosis and usually good visual acuity until the retinal degeneration involves the fovea. In vivo gene augmentation therapy is currently further explored in clinical trials of different stages.
Dr. med. Johannes Birtel, MBA, Prof. Dr. med. Frank G. Holz, Dr. med. Philipp Herrmann, PhD, Universitäts-Augenklinik Bonn, Universität Bonn, firstname.lastname@example.org
Conflict of interest statement: The authors have received third-party funding for the conduct of studies on behalf of Nightstar Therapeutics.
Translated from the original German by David Roseveare.
Cite this as: Birtel J, Holz FG, Herrmann P: Gene therapy approaches to a rare retinal disease: choroideremia. Dtsch Arztebl Int 2020; 117: 30. DOI: 10.3238/arztebl.2020.0030