Shuhei Kameya1, Kaoru Fujinami2,3,4,5, Shinji Ueno6, Takaaki Hayashi7, Kazuki Kuniyoshi8, Ryuichi Ideta9, Sachiko Kikuchi1,10, Daiki Kubota1, Kazutoshi Yoshitake11, Satoshi Katagiri7, Hiroyuki Sakuramoto8, Taro Kominami6, Hiroko Terasaki6, Lizhu Yang2,5, Yu Fujinami-Yokokawa2,12,13, Xiao Liu2,5,14, Gavin Arno2,3,4,15, Nikolas Pontikos2,3,4, Yozo Miyake16, Takeshi Iwata11, Kazushige Tsunoda2. 1. Department of Ophthalmology, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan. 2. Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan. 3. UCL Institute of Ophthalmology, London, United Kingdom. 4. Moorfields Eye Hospital, London, United Kingdom. 5. Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. 6. Department of Ophthalmology, Nagoya University Graduate School of Medicine, Aichi, Japan. 7. Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan. 8. Department of Ophthalmology, Kindai University Faculty of Medicine, Osaka, Japan. 9. IDETA Eye Hospital, Kumamoto City, Kumamoto, Japan. 10. Department of Ophthalmology, Chiba, Japan. 11. Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan. 12. Graduate School of Health Management, Keio University, Kanagawa, Japan. 13. Division of Public Health, Yokokawa Clinic, Osaka, Japan. 14. Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China. 15. North East Thames Regional Genetics Service, UCL Great Ormond Street Institute of Child Health, London, United Kingdom. 16. Aichi Medical University, Aichi, Japan.
Abstract
Purpose: Cone/cone-rod dystrophy is a large group of retinal disorders with both phonotypic and genetic heterogeneity. The purpose of this study was to characterize the phenotype of eight patients from seven families harboring POC1B mutations in a cohort of the Japan Eye Genetics Consortium (JEGC). Methods: Whole-exome sequencing with targeted analyses identified homozygous or compound heterozygous mutations of the POC1B gene in 7 of 548 families in the JEGC database. Ophthalmologic examinations including the best-corrected visual acuity, perimetry, fundus photography, fundus autofluorescence imaging, optical coherence tomography, and full-field and multifocal electroretinography (ERGs) were performed. Results: There were four men and four women whose median age at the onset of symptoms was 15.6 years (range, 6-23 years) and that at the time of examination was 40.3 years (range, 22-67 years). The best-corrected visual acuity ranged from -0.08 to 1.52 logMAR units. The funduscopic appearance was normal in all the cases except in one case with faint mottling in the fovea. Optical coherence tomography revealed an absence of the interdigitation zone and blurred ellipsoid zone in the posterior pole, but the foveal structures were preserved in three cases. The full-field photopic ERGs were reduced or extinguished with normal scotopic responses. The central responses of the multifocal ERGs were preserved in two cases. The diagnosis was either generalized cone dystrophy in five cases or cone dystrophy with foveal sparing in three cases. Conclusions: Generalized or peripheral cone dystrophy with normal funduscopic appearance is the representative phenotype of POC1B-associated retinopathy in our cohort.
Purpose: Cone/cone-rod dystrophy is a large group of retinal disorders with both phonotypic and genetic heterogeneity. The purpose of this study was to characterize the phenotype of eight patients from seven families harboring POC1B mutations in a cohort of the Japan Eye Genetics Consortium (JEGC). Methods: Whole-exome sequencing with targeted analyses identified homozygous or compound heterozygous mutations of the POC1B gene in 7 of 548 families in the JEGC database. Ophthalmologic examinations including the best-corrected visual acuity, perimetry, fundus photography, fundus autofluorescence imaging, optical coherence tomography, and full-field and multifocal electroretinography (ERGs) were performed. Results: There were four men and four women whose median age at the onset of symptoms was 15.6 years (range, 6-23 years) and that at the time of examination was 40.3 years (range, 22-67 years). The best-corrected visual acuity ranged from -0.08 to 1.52 logMAR units. The funduscopic appearance was normal in all the cases except in one case with faint mottling in the fovea. Optical coherence tomography revealed an absence of the interdigitation zone and blurred ellipsoid zone in the posterior pole, but the foveal structures were preserved in three cases. The full-field photopic ERGs were reduced or extinguished with normal scotopic responses. The central responses of the multifocal ERGs were preserved in two cases. The diagnosis was either generalized cone dystrophy in five cases or cone dystrophy with foveal sparing in three cases. Conclusions: Generalized or peripheral cone dystrophy with normal funduscopic appearance is the representative phenotype of POC1B-associated retinopathy in our cohort.