Kamron N Khan1,2,3, Emma C Lord3, Gavin Arno3, Farrah Islam2, Keren J Carss4,5, FLucy Raymond4,6, Carmel Toomes3, Manir Ali3, Chris F Inglehearn3, Andrew R Webster1,2, Anthony T Moore1,2,7, James A Poulter3, Michel Michaelides1,2. 1. University College London Institute of Ophthalmology, University College London, London, United Kingdom. 2. Medical Retina Service, Moorfields Eye Hospital, London, United Kingdom. 3. Section of Ophthalmology & Neuroscience, Leeds Institute of Biomedical & Clinical Sciences, St James' University Hospital, Leeds, United Kingdom. 4. NIHR BioResource-Rare Diseases, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, United Kingdom. 5. Department of Haematology, University of Cambridge, NHS Blood and Transplant Centre, Cambridge, United Kingdom. 6. Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom. 7. Department of Ophthalmology, University of California San Francisco Medical School, San Francisco, California.
Abstract
BACKGROUND: Albinism refers to a group of disorders primarily characterized by hypopigmentation. Affected individuals usually manifest both ocular and cutaneous features of the disease, but occasionally hair and skin pigmentation may appear normal. This is the case in ocular albinism, an X chromosome linked disorder resulting from mutation of GPR143. Female carriers may be recognized by a "mud-splatter" appearance in the peripheral retina. The macula is thought to be normal, however. METHODS: Obligate female carriers of pathogenic GPR143 alleles were recruited. Molecular confirmation of disease was performed only for atypical cases. Detailed retinal imaging was performed (colour fundus photography, optical coherence tomography, fundus autofluorescence. RESULTS: Eight individuals were ascertained. A novel GPR143 mutation was identified in one family (p.Gln328Ter). Foveal fundus autofluorescence was subjectively reduced in 6/6 patients imaged. A "tapetal-like" pattern of autofluorescence was visible at the macula in 3/6. Persistence of the inner retinal layers at the fovea was observed in 6/8 females. CONCLUSION: Female carriers of ocular albinism may manifest signs of retinal pigment epithelium mosaicism at the macula and the peripheral fundus. A tapetal-like reflex on fundus autofluorescence may be considered the macular correlate of "mud-splatter."
BACKGROUND: Albinism refers to a group of disorders primarily characterized by hypopigmentation. Affected individuals usually manifest both ocular and cutaneous features of the disease, but occasionally hair and skin pigmentation may appear normal. This is the case in ocular albinism, an X chromosome linked disorder resulting from mutation of GPR143. Female carriers may be recognized by a "mud-splatter" appearance in the peripheral retina. The macula is thought to be normal, however. METHODS: Obligate female carriers of pathogenic GPR143 alleles were recruited. Molecular confirmation of disease was performed only for atypical cases. Detailed retinal imaging was performed (colour fundus photography, optical coherence tomography, fundus autofluorescence. RESULTS: Eight individuals were ascertained. A novel GPR143 mutation was identified in one family (p.Gln328Ter). Foveal fundus autofluorescence was subjectively reduced in 6/6 patients imaged. A "tapetal-like" pattern of autofluorescence was visible at the macula in 3/6. Persistence of the inner retinal layers at the fovea was observed in 6/8 females. CONCLUSION: Female carriers of ocular albinism may manifest signs of retinal pigment epithelium mosaicism at the macula and the peripheral fundus. A tapetal-like reflex on fundus autofluorescence may be considered the macular correlate of "mud-splatter."
Authors: Maarjaliis Paavo; Jin Zhao; Hye Jin Kim; Winston Lee; Jana Zernant; Carolyn Cai; Rando Allikmets; Stephen H Tsang; Janet R Sparrow Journal: Invest Ophthalmol Vis Sci Date: 2018-05-01 Impact factor: 4.799