Macular degeneration in a Japanese patient with aceruloplasminemia.

PURPOSE: To characterize the clinical features of a Japanese patient with macular degeneration in aceruloplasminemia. METHODS: The clinical features were evaluated by visual acuity measurements, fluorescein angiography, electroretinography, and kinetic visual field testing. RESULTS: We observed a Japanese patient with macular degeneration in aceruloplasminemia. This patient also had diabetes mellitus and neurodegeneration. Ocular examination showed macular degeneration, which included yellow deposits around the macula area and no foveal reflex. CONCLUSION: It has been reported that Japanese patients with aceruloplasminemia have atrophy of the retinal pigment epithelium in the midperipheral area and yellowish discoloration of the fundus. However, the retinal findings and results of fluorescein angiography in our case were very similar to those for a white patient. We suggest that retinal degenerations in Japanese patients with aceruloplasminemia have clinical variability. We believe that impairment of iron metabolism caused by iron overload in the retina led to retinal degeneration in this case.

Screening of the MERTK gene for mutations in Japanese patients with autosomal recessive retinitis pigmentosa.

PURPOSE: To determine whether mutations in the MERTK gene are present in Japanese patients with autosomal recessive retinitis pigmentosa (arRP). METHODS: The coding sequence of all 19 exons and the adjacent flanking intron sequences of the MERTK gene were directly sequenced in 96 unrelated Japanese patients with arRP. RESULTS: Seventeen sequence variants were found; six missense changes, three isocoding changes, and eight intron changes were also observed. One arRP patient had a novel homozygous Leu12Pro missense mutation in the MERTK gene. CONCLUSIONS: Mutations in the MERTK gene are relatively rare in Japanese patients with arRP.

Mutations in the pre-mRNA splicing gene, PRPF31, in Japanese families with autosomal dominant retinitis pigmentosa.

PURPOSE: To describe the clinical and genetic characteristics of three Japanese families with autosomal dominant retinitis pigmentosa (ADRP) associated with mutations in the PRPF31 gene. DESIGN: Case reports and results of DNA analysis. METHODS: Mutational screening of the PRPF31 gene was performed on 96 unrelated patients with ADRP by direct sequencing. The clinical features were characterized by complete ophthalmologic examinations. RESULTS: Three mutations in the PRPF31 gene, designated as 1142delG, 1155-1159delGGACG/insAGGGATT, and IVS6 to 3 to -45del, were identified in three unrelated Japanese families with ADRP. The 1142delG and 1155-1159delGGACG/insAGGGATT mutations are novel. The phenotype of affected family members was typical of retinitis pigmentosa (RP). Additionally, we identified asymptomatic obligate carriers. CONCLUSIONS: The 1142delG and 1155-1159delGGACG/insAGGGATT mutations in the PRPF31 gene cause RP. The prevalence of mutations in the PRPF31 gene in Japanese patients with ADRP is approximately 3%. However, it is important to note that there are asymptomatic obligate carriers.

Screening for mutations in the IMPDH1 gene in Japanese patients with autosomal dominant retinitis pigmentosa.

PURPOSE: To determine the presence and frequency of mutations in the IMPDH1 gene in Japanese patients with autosomal dominant retinitis pigmentosa (ADRP), and to characterize the clinical characteristics of patients with the Lys238Arg mutation in the IMPDH1 gene. DESIGN: Case reports and results of DNA analysis. METHODS: All 14 coding exons of the IMPDH1 gene were directly sequenced in 96 unrelated patients with ADRP. The clinical features were determined by visual acuity, slit-lamp biomicroscopy, and kinetic visual field tests. RESULTS: Two novel mutations, a Leu227Pro and Lys238Arg, in the IMPDH1 gene were identified in two unrelated families with ADRP. The clinical features associated with the Lys238Arg mutation were an early-onset and severe retinal degeneration. CONCLUSIONS: The most commonly reported Asp226Asn mutation was not found in the Japanese population, instead two novel mutations were found. These findings suggest that mutations of the IMPDH1 gene cause ADRP in the Japanese population.

Introduction of the Low Vision Evaluator (LoVE) for children.

PURPOSE: To determine whether the Low Vision Evaluator (LoVE) can grade the visual acuity of young children with light perception and hand movement acuity into finer acuity steps and at what age reliable measurements can be obtained. METHODS: Two hundred twenty children were tested with the LoVE. Each eye was tested separately, and each stimulus magnitude (intensity x duration) was presented three times. Three catch trials per eye also were presented. RESULTS: Scores ranged from -8 to -1 on variable-duration tests and from 22.5 to 37.5 dB on fixed-duration tests for four children with hand movement vision. Scores ranged from -12 to 0 on variable-duration tests and from 12.5 to 40 dB on fixed-duration tests for five children with light perception vision. Reliable measurements were obtained at different times on different days. Mean scores for children with counting finger vision or better were significantly better than scores for eyes with light perception and hand movement (P < .001 and P < .01, respectively). Reliability was less for children younger than age 4 years. CONCLUSIONS: The LoVE is capable of grading the visual function of children with light perception and hand movement vision into finer steps. Reliable measurements can be obtained for children age 4 years and older.

Screening for mutations in CYP4V2 gene in Japanese patients with Bietti's crystalline corneoretinal dystrophy.

PURPOSE: To describe the clinical and genetic characteristics of six Japanese families with Bietti's crystalline corneoretinal dystrophy (BCD). DESIGN: Case reports and results of DNA analysis. METHODS: Mutation screening was performed on six unrelated patients with BCD by direct sequencing. The clinical features were characterized by the visual acuity, slit-lamp biomicroscopy, electroretinography, fluorescein angiography, and kinetic visual field testing. RESULTS: An identical IVS6 to 8delTCATACAGGTCATCGCG/insGC mutation in the CYP4V2 gene was identified in five of the patients with BCD; the sixth patient had a novel Trp340X mutation in the CYP4V2 gene. Three patients showed crystalline-like deposits at the limbus by specular microscopy. Ophthalmic findings of all patients had a rapid progression after age 50 years. CONCLUSIONS: Our findings suggest that the IVS6 to 8delTCATACAGGTCATCGCG/insGC mutation is a common mutation in Japanese patients with BCD. Although phenotypic variability was found, the natural course was almost the same in all of our patients.

Clinical features of Japanese families with a 402delT or a 555-556delAG mutation in choroideremia gene.

PURPOSE: To characterize the clinical features of two Japanese families with choroideremia associated with a 402delT and a 555-556delAG mutation in the choroideremia gene (CHM). METHODS: Four affected members and one obligate carrier from two Japanese families with choroideremia were studied. To detect mutations of the CHM gene, the products of polymerase chain reaction were directly sequenced in both directions. The ophthalmologic examination included best-corrected visual acuity, slit-lamp examination, fundus examination, kinetic perimetry, electroretinography, and fluorescein angiography. RESULTS: A 402delT and a 555-556delAG mutation were found in two Japanese families with choroideremia. All affected members had night-blindness, progressive constriction of the visual field, chorioretinal atrophy, and mottled appearance of the retinal pigment epithelium. The obligate carrier had mild patchy areas of retinal pigment epithelial atrophy with no visual symptoms. CONCLUSION: The authors found a 402delT and a 555-556delAG mutation in the CHM gene, one of which (402delT) is a novel mutation. They conclude that these mutations cause choroideremia in Japanese families.

Novel 615delC mutation in the CRX gene in a Japanese family with cone-rod dystrophy.

PURPOSE: To characterize the clinical features of a Japanese family with cone-rod dystrophy associated with a novel 615delC mutation in the cone-rod homeobox (CRX) gene. DESIGN: Case reports and results of DNA analysis. METHODS: Mutational screening by direct sequencing was performed for the three exons in the CRX gene. The clinical features were evaluated by visual acuity measurements, electroretinography, and kinetic visual field testing. RESULTS: A 615delC mutation in the CRX gene was identified and found to cosegregate with cone-rod dystrophy. The ophthalmic findings included cone-rod dystrophy with negative-type electroretinograms (ERGs) and a rapid progression after the age of 40 years. CONCLUSION: These findings indicate that the 615delC mutation causes cone-rod dystrophy with a negative-type ERG. The genotype-phenotype correlation in the CRX gene in our patient and others reported in the literature suggest that the negative-type ERG might be a good sign for having a mutation in the CRX gene.

An instrument capable of grading visual function: results from patients with retinitis pigmentosa.

There was no device to grade visual function in patients with retinitis pigmentosa (RP). We have therefore developed an instrument capable of measuring and quantifying the visual capabilities, and here present the results from patients with RP. In total, 118 eyes of 59 patients, 26 men and 33 women, with RP were studied. Seven eyes had hand movement (HM) and eight had light perception (LP) vision, and the others had better visual acuity. The Low Vision Evaluator (LoVE) consists of a pair of goggles with white, light-emitting diodes as the stimulus, a control box, an on-off button to signal the detection of the stimulus, and a printer for permanent records. There are 15 luminance levels of stimuli (combination of 5 intensities and 3 durations). The stimuli are delivered in a random sequence with an audio signal presented 0.3 seconds prior to the light stimulus. Each eye was tested separately, and each stimulus magnitude (intensity x duration) was presented 3 times for a total of 27 stimuli per eye. With 6 catch trials (audio signal without a light stimulus), a total of 60 trials were examined in a full examination. The conventional visual acuity and kinetic visual fields were determined. 59 patients had different visual acuities that ranged from no light perception (NLP) to 1.5 vision, and visual field sizes that ranged from 0.0001 to 3.96 steradians. The visual acuity and visual field size were significantly correlated with the LoVE score (r=0.58 and 0.64, respectively; p<0.01). These results indicate that the LoVE is capable of grading the visual function of RP patients with various visual acuities and visual fields. The testing procedures are simple for the patient and examiner, and this instrument can be used to assess the effectiveness of medical and surgical therapy.

Novel 2336-2337delCT mutation in RP1 gene in a Japanese family with autosomal dominant retinitis pigmentosa.

PURPOSE: To determine the frequency and kinds of mutations in the RP1 gene, and to characterize the clinical features of a Japanese family with autosomal dominant retinitis pigmentosa (ADRP) with a novel 2336 to 2337delCT mutation in the RP1 gene. DESIGN: Case reports and results of DNA analysis. METHODS: Mutational screening by direct sequencing was performed on 96 unrelated patients with ADRP. The clinical features were determined by complete ophthalmologic examinations. RESULTS: A novel 2336 to 2337delCT mutation in the RP1 gene was identified in two patients from a Japanese family with ADRP. In addition, three families with ADRP carried a previously reported nonpathogenic Arg1933X mutation. The ophthalmic findings with a 2336 to 2337delCT mutation were similar to those of typical retinitis pigmentosa with rapid progression after age 40 years. CONCLUSIONS: The most common Arg677X mutation in the white population was not found in the Japanese population; instead a novel mutation was found.

Clinical features of a Japanese family with autosomal dominant retinitis pigmentosa associated with a Thr494Met mutation in the HPRP3 gene.

PURPOSE: To determine the clinical features of a Japanese family with autosomal dominant retinitis pigmentosa (ADRP) associated with a Thr494Met mutation in the HPRP3 gene. METHODS: Mutational screening by direct sequencing was performed on 96 unrelated patients with ADRP. The clinical features were determined by visual acuity, slit-lamp biomicroscopy, electroretinography, fluorescein angiography, and kinetic visual field testing. RESULTS: A Thr494Met mutation in the HPRP3 gene was found in one family and it cosegregated with ADRP in the three affected members. The ophthalmic findings were those of typical retinitis pigmentosa with rapid progression after 40-years-of-age. One patient also had retinoblastoma as a child. CONCLUSION: We conclude that the Thr494Met mutation in the HPRP3 gene causes ADRP in Japanese patients. This mutation was found in 1% of patients with ADRP in Japan.

Autosomal dominant macular degeneration associated with 208delG mutation in the FSCN2 gene.

OBJECTIVE: To assess the clinical and genetic characteristics of 2 Japanese families with autosomal dominant macular degeneration (ADMD) associated with a 208delG mutation in the retinal fascin (FSCN2) gene. DESIGN: Case reports with clinical findings and results of fluorescein angiography, electroretinography, kinetic visual field testing, and DNA analysis. SETTING: University medical center. RESULTS: The 208delG mutation in the FSCN2 gene was identified in 14 members of 4 Japanese families with autosomal dominant retinitis pigmentosa and in 5 members of 2 Japanese families with ADMD. The characteristic features associated with this mutation led to 2 different phenotypes, autosomal dominant retinitis pigmentosa and ADMD. CONCLUSIONS: The 208delG mutation in the FSCN2 gene produces not only autosomal dominant retinitis pigmentosa but also ADMD in the Japanese population. This mutation is relatively common in Japanese patients with autosomal dominant retinal degeneration and showed clinical variability. CLINICAL RELEVANCE: Autosomal dominant retinitis pigmentosa and ADMD can be caused by the same 208delG mutation. We suggest that mutations in the FSCN2 gene can lead to a spectrum of phenotypes.

Ocular findings in a Japanese family with an Arg41Trp mutation of the CRX gene.

PURPOSE: To characterize the ophthalmological features and clinical course of an autosomal dominant cone-rod dystrophy (CORD2) in a Japanese family with an Arg41Trp mutation in the CRX gene. METHODS: Mutation screening by direct sequencing was performed on 42 patients with cone-rod dystrophy. The clinical features of the patients were characterized by the visual acuity and by the findings of slit-lamp biomicroscopy, electroretinography, fluorescein angiography, and kinetic visual field testing. RESULTS: An Arg41Trp mutation in the CRX gene was identified in three members from three generations of one family with cone-rod dystrophy. Fundus examination demonstrated that the retinal dystrophy worsened with increasing age. CONCLUSIONS: A heterozygous Arg41Trp mutation in the CRX gene can produce cone-rod dystrophy in Japanese patients. Clinical examination of patients of different ages demonstrated that there was a rapid progressive worsening of the disease with increasing age.