Kazuki Kuniyoshi1, Takaaki Hayashi2, Hiroyuki Sakuramoto3, Hiroshi Mishima3, Hiroshi Tsuneoka2, Kazushige Tsunoda4, Takeshi Iwata5, Yoshikazu Shimomura3. 1. Department of Ophthalmology, Kinki University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan. kuniyoshi-kazuki@umin.net. 2. Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan. 3. Department of Ophthalmology, Kinki University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan. 4. Laboratory of Visual Physiology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan. 5. Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
Abstract
PURPOSE: The enhanced S-cone syndrome (ESCS) is a rare hereditary retinal degeneration that has enhanced short wavelength-sensitive cone (S-cone) functions. The longitudinal clinical course of this disease has been rarely reported, and the genetic aspects of ESCS have not been well investigated in the Japanese population. In this report, we present our clinical and genetic findings for 2 patients with ESCS. PATIENTS AND METHODS: The patients were 2 unrelated Japanese men. Standard ophthalmic examinations and mutation screening for the NR2E3 gene were performed. RESULTS: Patient 1 was a 36-year-old man, and his clinical findings were typical of ESCS. His decimal best-corrected visual acuity (BCVA) was 1.0 OD and 0.5 OS after removal of cataracts. Genetic investigations revealed a homozygous truncation frameshift, the p.I307LfsX33 mutation. Patient 2 was an 11-year-old boy when he was first examined by us. His clinical findings were typical of ESCS except for uveitis in the left eye. His decimal BCVA at the age of 39 years was maintained at 1.5 in each eye, although the retinal degeneration and visual field impairments had progressed during the follow-up period. The genetic investigations revealed homozygous mutations of p.R104Q in the NR2E3 gene. CONCLUSIONS: The frameshift mutation, p.I307LfsX33, in the NR2E3 gene is a new causative mutation for ESCS. The clinical observations for patient 2 are the longest ever reported. The retinal degeneration caused by this mutation is slowly progressive, and these patients maintained good vision with maintenance of the foveal structure until their late thirties.
PURPOSE: The enhanced S-cone syndrome (ESCS) is a rare hereditary retinal degeneration that has enhanced short wavelength-sensitive cone (S-cone) functions. The longitudinal clinical course of this disease has been rarely reported, and the genetic aspects of ESCS have not been well investigated in the Japanese population. In this report, we present our clinical and genetic findings for 2 patients with ESCS. PATIENTS AND METHODS: The patients were 2 unrelated Japanese men. Standard ophthalmic examinations and mutation screening for the NR2E3 gene were performed. RESULTS:Patient 1 was a 36-year-old man, and his clinical findings were typical of ESCS. His decimal best-corrected visual acuity (BCVA) was 1.0 OD and 0.5 OS after removal of cataracts. Genetic investigations revealed a homozygous truncation frameshift, the p.I307LfsX33 mutation. Patient 2 was an 11-year-old boy when he was first examined by us. His clinical findings were typical of ESCS except for uveitis in the left eye. His decimal BCVA at the age of 39 years was maintained at 1.5 in each eye, although the retinal degeneration and visual field impairments had progressed during the follow-up period. The genetic investigations revealed homozygous mutations of p.R104Q in the NR2E3 gene. CONCLUSIONS: The frameshift mutation, p.I307LfsX33, in the NR2E3 gene is a new causative mutation for ESCS. The clinical observations for patient 2 are the longest ever reported. The retinal degeneration caused by this mutation is slowly progressive, and these patients maintained good vision with maintenance of the foveal structure until their late thirties.
Authors: M Kobayashi; S Takezawa; K Hara; R T Yu; Y Umesono; K Agata; M Taniwaki; K Yasuda; K Umesono Journal: Proc Natl Acad Sci U S A Date: 1999-04-27 Impact factor: 11.205