Prurigo pigmentosa in a patient with primary biliary cirrhosis and Sjögren syndrome

A 44‐year‐old Japanese woman suddenly developed severely pruritic erythematous papules on her trunk in a symmetrical distribution. Biopsy specimens showed the typical histopathological findings of prurigo pigmentosa. She had had recurrent episodes of high fever spikes for several years, and lost 10 kg in the last year. She was diagnosed as primary biliary cirrhosis (PBC) associated with subclinical Sjögren syndrome (SjS). Predonisolone (60 mg/day) for two weeks was effective for the PBC and fever, but not for the prurigo pigmentosa. PBC may be involved in the pathogenesis of this rare skin disease.     

Inner retinal abnormalities in a mouse model of Leber's congenital amaurosis

Leber's congenital amaurosis (LCA) is the earliest and most severe form in the world of genetic retinal dystrophy causing blindness. An animal model of LCA was recently created in which the cone-rod homeobox (crx) gene was disrupted using homologous recombination. Crx-/- mice display abnormal development of photoreceptors followed by their degeneration. We analyzed the morphology of inner retinal cells in crx-/- mice in order to evaluate the effects of abnormal photoreceptor development and death upon other retinal neurons. The identification of a time window during which inner retinal cells are still viable could be very important in view of the possibilities that photoreceptor transplantation or gene therapy might be used to restore vision in LCA. We used a combination of immunocytochemical and confocal microscopy techniques to screen the crx-/- inner retina and verify its morphological integrity after photoreceptor degeneration. We found significant morphological alterations in second-order neurons in crx-/- animals. The appearance of mutant retinas after photoreceptor death is indistinguishable from that of the retinal degeneration (rd/rd) mouse, a different genetic model of a retinal disease characterized by photoreceptor degeneration. However, at early stages of photoreceptor degeneration the morphology of retinal cells in the crx-/- mutant is considerably well preserved. It is likely that different genetic mechanisms that cause abnormal photoreceptor development and/or degeneration lead to a common pathway that determines second-order neuron modifications. The severity of modifications is linked to the timing of onset of the degeneration and appears to increase with time.     

Survey in to the Prevalence of Hearing Loss in Patients Diagnosed with Retinitis Pigmentosa

Sensorineural hearing loss is the most common disease associated with systemic retinitis pigmentosa (RP). We have conducted an epidemiological study to assess the correlation of age at onset of visual symptoms and hearing loss associated with RP. Epidemiological data was derived from a questionnaire-based study of patients who are registered members of the Japanese Retinitis Pigmentosa Society (n = 3200). The questionnaire was mailed to these patients in 2002, and information was requested regarding age at onset of visual disturbance, awareness of hearing loss and the presence of progressive hearing loss, age at onset of hearing loss, awareness of tinnitus, and history of audiometric examination and hearing aid usage. 26.1% of the questionnaires were returned, and data for 828 patients with RP diagnosed by an ophthalmologist were evaluated. Cochlear symptoms were reported by 356 patients (43.0% of the total population), with hearing loss in 29.5%, tinnitus in 31.5% and hearing loss and tinnitus in 39.3% of the 356 patients. Of these 356 patients, progressive hearing loss was reported by 44.9% and was independent of age at onset of cochlear symptoms. The mean age at onset of visual symptoms was higher for patients with progressive hearing loss, and a significant correlation was found between the age at onset of visual symptoms and hearing loss for patients who were older at onset of the symptoms (>30 years of age). Onset of hearing loss occurs later and hearing loss is also more progressive for patients with late onset of RP. This suggests that particular care regarding hearing loss is necessary for this patient population, and that cooperation between opthalmologists and otologists is required for diagnosis of RP-hearing impairment-associated syndromes in this group of patients.     

L-NAME protects against acute light damage in albino rats,but not against retinal degeneration in P23H and S334ter transgenic rats

Two previous studies have shown that N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of neuronal nitric oxide synthase, protects retinas of albino rats and mice from damaging levels of light. The aims of the present study were two-fold: (1) to confirm the protective effect of L-NAME on wild type albino rats and (2) to determine if L-NAME protects the retinas of transgenic rats with P23H and S334ter rhodopsin mutations. In the first study, albino rats born and raised in 5-10 lux cyclic light were injected intraperitoneally with either L-NAME or its inactive isomer D-NAME 30 min before being placed in bright light (2700 lux) for 24hr. Electroretinograms (ERGs) were recorded before light treatment and 2 days after cessation of exposure, and eyes were enucleated for morphologic evaluation. L-NAME, but not D-NAME provided structural protection of photoreceptor cells from light damage. The functional rescue was not statistically significant between the drug treated groups. In the second study, albino WT, P23H transgenic, and S334ter transgenic rats were born and raised in 400 lux cyclic light. Three week old animals received daily intraperitoneal injections of L-NAME or D-NAME for 4 weeks, and the same drugs were added to their drinking water. At 7 weeks of age, the ERG sensitivity curves and the outer nuclear layer thickness of both transgenic groups were significantly reduced compared to WT controls. However, administration of L-NAME did not protect against retinal degeneration caused by the rhodopsin mutation in either strain of transgenic (P23H and S334ter) rats. Thus, although photoreceptor cell death in light damage and inherited retinal degenerations share a common apoptotic mechanism, there must be significant 'up-stream' differences that allow selective neuroprotection by L-NAME.     

Differenzierte Untersuchung der Netzhautfunktion bei regionaler Retinitis pigmentosa mit Hilfe des multifokalen Elektroretinogramms

Purpose. Generalized retinal degenerations such as retinitis pigmentosa may manifest with focal retinal dysfunctions. These may be detected objectively by new electrophysiological techniques, such as multifocal electroretinography (ERG). Case report. A mother and daughter, aged 81 and 46 years, showed bilateral caudal bone spiculae formations with corresponding cranial visual field defects in the static perimetry of the central visual field (Octopus) and in the kinetic perimetry (Goldmann). Results. Pattern VEP, pattern ERG, EOG, and cone ERG were within the normal range. The scotopic ERG was in the lower normal range. The multifocal cone ERG of the central 50° showed reduced amplitudes and prolonged latencies in the first-order response component. These findings corresponded to the area of the bone spiculae and the scotomata. Conclusion. Multifocal ERG enables the detection of focal retinal cone dysfunction in segmental retinitis pigmentosa. It is an additional tool that may aid in the diagnosis and classification of this disease.     

Novel homozygous loss-of-function mutations in RP1 and RP1L1 genes in retinitis pigmentosa patients

ABSTRACT

Background: Retinitis pigmentosa (RP) is a heterogeneous group of ocular dystrophy. It is challenging to identify the underlying genetic defect in individuals with RP due to huge genetic heterogeneity. This study was designed to delineate the genetic defect(s) underlying RP in extended Saudi families and to describe the possible disease mechanism.

Materials and Methods: Fundus photography and a high definition optical coherence tomography (HD-OCT) were performed in order to detect the earlier stages of macular degeneration. Genomic DNA was extracted followed by genome-wide SNP genotyping and whole exome sequencing (WES). Exome data was filtered to identify the genetic variant(s) of interest.

Results: Clinical examination showed that affected individuals manifest key features of RP. The fundus exam shows pale optic disc and bone spicules at the periphery. OCT shows macular degeneration as early as at the age of 4 years. Whole genome scan by SNPs identified multiple homozygous regions. WES identified a 10 bps novel insertion mutation (c.3544_3545insAGAAAAGCTG; p.Ala1182fs) in the RP1 gene in both affected individuals of family A. Affected individual from family B showed a large insertion of 48 nucleotides in the coding part of the RP1L1 gene (c.3955_3956insGGACTAAAGTAATAGAAGGGCTGCAAGAAGAGAGGGTGCAGTTAGAGG; p.Ala1319fs). Sanger sequencing validates the autosomal recessive inheritance of the mutations.

Conclusion: The results strongly suggest that the insertion mutations in the RP1 and RP1L1 genes are responsible for the retinal phenotype in affected individuals from two families. Heterozygous individuals are asymptomatic carriers. We propose that the protective allele in other homozygous regions in heterozygous carriers contribute to the phenotypic variability in asymptomatic individuals.     

眼病候选基因芯片在一汉族视网膜色素变性家系分子遗传学中的应用

背景 视网膜色素变性(RP)是一种累及视网膜光感受器细胞及色素上皮细胞的遗传性致盲眼病.RP的发病机制及临床特征较复杂,具有遗传异质性和临床异质性.随着基因组学的迅猛发展,越来越多的研究手段应用于RP致病基因筛查.目的 通过眼科基因芯片测序方法探讨一常染色体遗传RP家系临床表型及其基因突变情况.方法 于2013年6月在重庆市荣昌县收集一汉族RP家系,对该家系所有患者进行眼科检查确诊后,抽取12名家系成员外周静脉血各1 ml,应用华大基因眼科芯片目标区域捕获技术进行基因突变检测.该基因芯片覆盖了眼病相关的基因编码区(包括59个RP候选基因),选择家系内2例RP患者(Ⅱ5、Ⅱ7)的DNA样本进行目标区域捕获测序.通过生物信息学技术对测序结果进行分析,对共有的变异位点进行Sanger测序验证.结果 该家系为常染色体遗传的RP家系.通过基因芯片分析发现该家系Ⅱ5和Ⅱ7患者存在2个共有基因突变:USH2A (c.3065T＞C,p.Phe1022Ser)突变和PDE6A(c.1699G＞A,p.Ala1319Gly)突变,家系其他成员检测结果表明2个基因突变未与疾病共分离.该眼科基因芯片高通量测序技术虽然未定位该家系致病基因,但快速排除了RP常见候选基因,为进一步分析奠定了研究基础.结论 采用基于目标区域捕获测序的眼科基因芯片技术可以快速、准确地筛查RP常见候选基因,是眼科疾病遗传研究的一项适用且高效的新方法.     

X-连锁隐性视网膜色素变性的分子遗传学分析

目的探讨1个X-连锁隐性视网膜色素变性(X-linkedrecessiveretinitispigmentosa,XLRRP)家系先证者分子遗传学基础。方法应用聚合酶链反应-直接测序,检测与XLRP相关基因视网膜GTP酶调节因子(retinitispigmentosaGTPaseregulator,RPGR)基因的所有外显子和突变热区15号外显子开放阅读框(exonopenreadingframe15,ORF15)及其与内含子交界处序列。结果检测到2种新的同义突变,c.2166A>G(Glu722)和c.3396C>T(Asp1132),都位于ORF15;以及4种已知多态c.29-15G>A,c.469 63C>T,c.1227 67A>G和c.1675-101A>T。结论尚不能确定此XLRP家系的疾病相关基因。     

Retinitis Pigmentosa Sine Pigmento Mimicking a Chiasm Disease

A 75-year-old woman presented to her ophthalmologist complaining of visual loss for several years. The ophthalmic examination was remarkable for a bitemporal visual field defect. Magnetic resonance imaging (MRI) scan of the brain was normal without evidence of chiasm compression. Neuro-ophthalmic examination was consistent with a retinal rather than a chiasmal disease. Retinal multimodal imaging helped in the correct diagnosis of retinitis pigmentosa, later confirmed by genetic testing.