The landscape of submicroscopic structural variants at the OPN1LW/OPN1MW gene cluster on Xq28 underlying blue cone monochromacy.

Blue cone monochromacy (BCM) is an X-linked retinal disorder characterized by low vision, photoaversion, and poor color discrimination. BCM is due to the lack of long-wavelength-sensitive and middle-wavelength-sensitive cone photoreceptor function and caused by mutations in the OPN1LW/OPN1MW gene cluster on Xq28. Here, we investigated the prevalence and the landscape of submicroscopic structural variants (SVs) at single-base resolution in BCM patients. We found that about one-third (n = 73) of the 213 molecularly confirmed BCM families carry an SV, most commonly deletions restricted to the OPN1LW/OPN1MW gene cluster. The structure and precise breakpoints of the SVs were resolved in all but one of the 73 families. Twenty-two families-all from the United States-showed the same SV, and we confirmed a common ancestry of this mutation. In total, 42 distinct SVs were identified, including 40 previously unreported SVs, thereby quadrupling the number of precisely mapped SVs underlying BCM. Notably, there was no "region of overlap" among these SVs. However, 90% of SVs encompass the upstream locus control region, an essential enhancer element. Its minimal functional extent based on deletion mapping in patients was refined to 358 bp. Breakpoint analyses suggest diverse mechanisms underlying SV formation as well as in one case the gene conversion-based exchange of a 142-bp deletion between opsin genes. Using parsimonious assumptions, we reconstructed the composition and copy number of the OPN1LW/OPN1MW gene cluster prior to the mutation event and found evidence that large gene arrays may be predisposed to the occurrence of SVs at this locus.

DNAJC30 disease-causing gene variants in a large Central European cohort of patients with suspected Leber's hereditary optic neuropathy and optic atrophy.

BACKGROUND: Leber's hereditary optic neuropathy (LHON) has been considered a prototypical mitochondriopathy and a textbook example for maternal inheritance linked to certain disease-causing variants in the mitochondrial genome. Recently, an autosomal recessive form of LHON (arLHON) has been described, caused by disease-causing variants in the nuclear encoded gene DNAJC30. METHODS AND RESULTS: In this study, we screened the DNAJC30 gene in a large Central European cohort of patients with a clinical diagnosis of LHON or other autosomal inherited optic atrophies (OA). We identified likely pathogenic variants in 35/1202 patients, corresponding to a detection rate of 2.9%. The previously described missense variant c.152A>G;p.(Tyr51Cys) accounts for 90% of disease-associated alleles in our cohort and we confirmed a strong founder effect. Furthermore, we identified two novel pathogenic variants in DNAJC30: the nonsense variant c.610G>T;p.(Glu204*) and the in-frame deletion c.230_232del;p.(His77del). Clinical investigation of the patients with arLHON revealed a younger age of onset, a more frequent bilateral onset and an increased clinically relevant recovery compared with LHON associated with disease-causing variants in the mitochondrial DNA. CONCLUSION: This study expands previous findings on arLHON and emphasises the importance of DNAJC30 in the genetic diagnostics of LHON and OA in European patients.

Transcorneal Electrical Stimulation for the Treatment of Retinitis Pigmentosa: A Multicenter Safety Study of the OkuStim® System (TESOLA-Study).

BACKGROUND: Transcorneal electrical stimulation (TES) has been suggested as a possible treatment for retinitis pigmentosa (RP). OBJECTIVE: To expand the safety assessment of repeated applications of an electrical current from a DTL-like electrode in patients with RP. METHODS: This single-arm open label interventional safety trial included a total of 105 RP patients from 11 European centers, who received weekly TES for 6 months on 1 eye followed by observation for another 6 months without stimulation. The primary outcome measure was safety, indicated by the frequency and severity of adverse events. Secondary measures included intraocular pressure and central retinal thickness. Visual field and visual acuity were examined using the methods available at each site. RESULTS: Dry eye sensation was the most common adverse event recorded (37.5%). Serious adverse events secondary to TES were not observed. Most adverse events were mild and all resolved without sequelae. The secondary outcome measures revealed no significant or clinically relevant changes. CONCLUSION: The present results confirm the excellent safety profile of TES. Transient dry eye symptoms were the most common adverse event.

Mutation spectrum and clinical investigation of achromatopsia patients with mutations in the GNAT2 gene.

Achromatopsia (ACHM) is a hereditary cone photoreceptor disorder characterized by the inability to discriminate colors, nystagmus, photophobia, and low-visual acuity. Six genes have been associated with this rare autosomal recessively inherited disease, including the GNAT2 gene encoding the catalytic α-subunit of the G-protein transducin which is expressed in the cone photoreceptor outer segment. Out of a cohort of 1,116 independent families diagnosed with a primary clinical diagnosis of ACHM, we identified 23 patients with ACHM from 19 independent families with likely causative mutations in GNAT2, representing 1.7% of our large ACHM cohort. In total 22 different potentially disease-causing variants, of which 12 are novel, were identified. The mutation spectrum also includes a novel copy number variation, a heterozygous duplication of exon 4, of which the breakpoint matches exactly that of the previously reported exon 4 deletion. Two patients carry just a single heterozygous variant. In addition to our previous study on GNAT2-ACHM, we also present detailed clinical data of these patients.

[Hereditary Optic Neuropathies]. / Erbliche Sehnerverkrankungen.

Hereditary optic nerve disorders are rare. For ophthalmologists, Leber's hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (ADOA) are of particular relevance. LHON and ADOA are diseases of the retinal ganglion cells and are caused by mitchochondrial dysfunction. LHON is based on mutations of the mitochondrial, ADOA of the nuclear DNA. LHON is a disease that usually leads to severe visual impairment (visual acuity < 0.1). Since there is an approved therapy for LHON (Idebenone [Raxone]), the diagnosis has to be confirmed immediately by means of molecular genetic diagnostics. ADOA usually shows less severe visual impairment, begins in childhood, and progresses gradually, often for a long time without any noticeable worsening. Family history (dominant heredity) and blue colour vision disorder are the leading indicators for the diagnosis of ADOA, which should be confirmed by molecular genetic testing. Optic nerve diseases can also occur in the context of hereditary, syndromic disorders. Ophthalmologically relevant are Wolfram syndrome, Friedreich's ataxia and Charcot-Marie-Tooth disease. In all hereditary optic nerve disorders, foods containing cyanide and smoking should be avoided. Excessive alcohol consumption is considered to be a trigger of LHON and possibly harmful in other hereditary optic neuropathies. In the management of patients with hereditary optic nerve disorders, aspects of rehabilitation as well as social and psychological care should be considered.

Influence of chloroquine intake on the multifocal electroretinogram in patients with and without maculopathy.

PURPOSE: To evaluate the effect of long-term chloroquine intake on the multifocal electroretinogram (mfERG) in female patients with and without maculopathy. METHODS: Retrospective analysis of the mfERGs recorded in three different groups: (1) patients with bilateral maculopathy having taken chloroquine, (2) patients without maculopathy having taken chloroquine, and (3) healthy control subjects (age-matched to group 2) who never took chloroquine. MfERGs of each group were averaged, and the data of each patient group were compared to the control group. The main outcome measures were N1 and P1 characteristics and the ring ratio analysis. RESULTS: In group 1, 11 female subjects (22 eyes) were included, group 2 consisted of nine patients (18 eyes) and group 3 of seven healthy female subjects (14 eyes). Compared with healthy controls, patients in group 1 showed significantly reduced response densities of both N1 and P1 across all ring eccentricities except ring 5. Implicit times were significantly delayed only concerning N1 (ring 4 and the sum response of the left eye of group 1). P1 implicit times showed no significant alterations in either group. Ring ratios of the response densities were significantly higher mainly concerning group 1 (N1: ring 5/ring 2 and ring 5/ring 4 of the right eye; P1: all ring ratios of the right eye and all ratios except ring 5/ring 1 and ring 5/ring 4 of the left eye). The only ring ratio being significantly higher in group 2 was P1 ring 5/ring 1 ratio of the right eye. CONCLUSIONS: In the absence of clinically apparent maculopathy, chloroquine intake was not associated with major alterations of the mfERG.

Phenotyping heterozygous carriers of juvenile neuronal ceroid lipofuscinosis with CLN3 mutations.

PURPOSE: The objective of this study was to establish an ophthalmologic phenotype of heterozygous carriers of juvenile neuronal ceroid lipofuscinosis (CLN3 disease, Batten disease). METHODS: The eyes and vision of nine heterozygous carriers of juvenile neuronal ceroid lipofuscinosis with classical CLN3 mutations were examined using the following methods: clinical examination, visual acuity, ophthalmoscopy, optical coherence tomography (macular thickness and peripapillary retinal nerve fibre layer measurement [RNFL]), fundus autofluorescence measurement, infrared imaging, and full-field and multifocal electroretinogram. Optical coherence tomography and electrophysiological data were statistically compared with age- and sex-matched control groups. RESULTS: The basic clinical examination as well as the fundus autofluorescence and infrared images of the macular region were unremarkable. Neither the electrophysiological examinations nor optical coherence tomography yielded fundamental abnormalities. There were only two significant-albeit most likely clinically irrelevant-differences that occurred in comparison to the control group: a decrease in RNFL of the nasal quadrant in the OCT and a prolongation of the N1 implicit time of the second-ring eccentricity in the multifocal electroretinogram. CONCLUSIONS: The eyes and vision of heterozygous carriers of CLN3 disease showed normal features when compared to a control group, which controverts a previously suggested retinal dysfunction in these subjects.

Targeted disruption of the murine retinal dehydrogenase gene Rdh12 does not limit visual cycle function.

RDH12 codes for a member of the family of short-chain alcohol dehydrogenases/reductases proposed to function in the visual cycle that supplies the chromophore 11-cis retinal to photoreceptor cells. Mutations in RDH12 cause severe and progressive childhood onset autosomal-recessive retinal dystrophy, including Leber congenital amaurosis. We generated Rdh12 knockout mice, which exhibited grossly normal retinal histology at 10 months of age. Levels of all-trans and 11-cis retinoids in dark- and light-adapted animals and scotopic and photopic electroretinogram (ERG) responses were similar to those for the wild type, as was recovery of the ERG response following bleaching, for animals matched for an Rpe65 polymorphism (p.L450M). Lipid peroxidation products and other measures of oxidative stress did not appear to be elevated in Rdh12(-/-) animals. RDH12 was localized to photoreceptor inner segments and the outer nuclear layer in both mouse and human retinas by immunohistochemistry. The present findings, together with those of earlier studies showing only minor functional deficits in mice deficient for Rdh5, Rdh8, or Rdh11, suggest that the activity of any one isoform is not rate limiting in the visual response.

De novo double mutation in PAX6 and mtDNA tRNA(Lys) associated with atypical aniridia and mitochondrial disease.

We report on the clinical, molecular and biochemical findings of a patient with the rare event (<4.02 x 10(-9) per generation) of coinciding de novo mutations in the nuclear PAX6 (c.1252-1267del16) and the mitochondrial mt.RNA (Lys) (8347A-->G) genes. The boy suffers from exercise intolerance, ptosis, nystagmus, macular hypoplasia and anterior segment abnormalities evocative of Axenfeld-Rieger anomaly. The PAX6 mutation is predicted to cause haploinsufficiency. The novel mt.RNA (Lys) mutation is located close to the classic myoclonic epilepsy with ragged-red-fibers mutation, but the patient exhibits neither myoclonic epilepsy nor ragged-red-fibers. The degree of mutant mtDNA heteroplasmy, as determined by a very accurate pyrosequencing assay, varies between 31% (muscle) and 38% (fibroblasts). We discuss a potential effect of the PAX6 mutation on the mtDNA mutation rate.

Mutation Spectrum of the ABCA4 Gene in 335 Stargardt Disease Patients From a Multicenter German Cohort-Impact of Selected Deep Intronic Variants and Common SNPs.

Purpose: Stargardt disease (STGD1) is an autosomal recessive retinopathy, caused by mutations in the retina-specific ATP-binding cassette transporter (ABCA4) gene. To establish the mutational spectrum and to assess effects of selected deep intronic and common genetic variants on disease, we performed a comprehensive sequence analysis in a large cohort of German STGD1 patients. Methods: DNA samples of 335 STGD1 patients were analyzed for ABCA4 mutations in its 50 coding exons and adjacent intronic sequences by resequencing array technology or next generation sequencing (NGS). Parts of intron 30 and 36 were screened by Sanger chain-terminating dideoxynucleotide sequencing. An in vitro splicing assay was used to test selected variants for their splicing behavior. By logistic regression analysis we assessed the association of common ABCA4 alleles while a multivariate logistic regression model calculated a genetic risk score (GRS). Results: Our analysis identified 148 pathogenic or likely pathogenic mutations, of which 48 constitute so far unpublished ABCA4-associated disease alleles. Four rare deep intronic variants were found once in 472 alleles analyzed. In addition, we identified six risk-modulating common variants. Genetic risk score estimates suggest that defined common ABCA4 variants influence disease risk in carriers of a single pathogenic ABCA4 allele. Conclusions: Our study adds to the mutational spectrum of the ABCA4 gene. Moreover, in our cohort, deep intronic variants in intron 30 and 36 likely play no or only a minor role in disease pathology. Of note, our findings demonstrate a possible modifying effect of common sequence variants on ABCA4-associated disease.

Next-generation sequencing reveals the mutational landscape of clinically diagnosed Usher syndrome: copy number variations, phenocopies, a predominant target for translational read-through, and PEX26 mutated in Heimler syndrome.

BACKGROUND: Combined retinal degeneration and sensorineural hearing impairment is mostly due to autosomal recessive Usher syndrome (USH1: congenital deafness, early retinitis pigmentosa (RP); USH2: progressive hearing impairment, RP). METHODS: Sanger sequencing and NGS of 112 genes (Usher syndrome, nonsyndromic deafness, overlapping conditions), MLPA, and array-CGH were conducted in 138 patients clinically diagnosed with Usher syndrome. RESULTS: A molecular diagnosis was achieved in 97% of both USH1 and USH2 patients, with biallelic mutations in 97% (USH1) and 90% (USH2), respectively. Quantitative readout reliably detected CNVs (confirmed by MLPA or array-CGH), qualifying targeted NGS as one tool for detecting point mutations and CNVs. CNVs accounted for 10% of identified USH2A alleles, often in trans to seemingly monoallelic point mutations. We demonstrate PTC124-induced read-through of the common p.Trp3955* nonsense mutation (13% of detected USH2A alleles), a potential therapy target. Usher gene mutations were found in most patients with atypical Usher syndrome, but the diagnosis was adjusted in case of double homozygosity for mutations in OTOA and NR2E3, genes implicated in isolated deafness and RP. Two patients with additional enamel dysplasia had biallelic PEX26 mutations, for the first time linking this gene to Heimler syndrome. CONCLUSION: Targeted NGS not restricted to Usher genes proved beneficial in uncovering conditions mimicking Usher syndrome.

De novo intrachromosomal gene conversion from OPN1MW to OPN1LW in the male germline results in Blue Cone Monochromacy.

X-linked cone dysfunction disorders such as Blue Cone Monochromacy and X-linked Cone Dystrophy are characterized by complete loss (of) or reduced L- and M- cone function due to defects in the OPN1LW/OPN1MW gene cluster. Here we investigated 24 affected males from 16 families with either a structurally intact gene cluster or at least one intact single (hybrid) gene but harbouring rare combinations of common SNPs in exon 3 in single or multiple OPN1LW and OPN1MW gene copies. We assessed twelve different OPN1LW/MW exon 3 haplotypes by semi-quantitative minigene splicing assay. Nine haplotypes resulted in aberrant splicing of ≥20% of transcripts including the known pathogenic haplotypes (i.e. 'LIAVA', 'LVAVA') with absent or minute amounts of correctly spliced transcripts, respectively. De novo formation of the 'LIAVA' haplotype derived from an ancestral less deleterious 'LIAVS' haplotype was observed in one family with strikingly different phenotypes among affected family members. We could establish intrachromosomal gene conversion in the male germline as underlying mechanism. Gene conversion in the OPN1LW/OPN1MW genes has been postulated, however, we are first to demonstrate a de novo gene conversion within the lineage of a pedigree.

Sustained Neural Stem Cell-Based Intraocular Delivery of CNTF Attenuates Photoreceptor Loss in the nclf Mouse Model of Neuronal Ceroid Lipofuscinosis.

A sustained intraocular administration of neurotrophic factors is among the strategies aimed at establishing treatments for currently untreatable degenerative retinal disorders. In the present study we have analyzed the neuroprotective effects of a continuous neural stem (NS) cell-based intraocular delivery of ciliary neurotrophic factor (CNTF) on photoreceptor cells in the nclf mouse, an animal model of the neurodegenerative lysosomal storage disorder variant late infantile neuronal ceroid lipofuscinosis (vLINCL). To this aim, we genetically modified adherently cultivated NS cells with a polycistronic lentiviral vector encoding a secretable variant of CNTF together with a Venus reporter gene (CNTF-NS cells). NS cells for control experiments (control-NS cells) were modified with a vector encoding the reporter gene tdTomato. Clonal CNTF-NS and control-NS cell lines were established using fluorescent activated cell sorting and intravitreally grafted into 14 days old nclf mice at the onset of retinal degeneration. The grafted cells preferentially differentiated into astrocytes that were attached to the posterior side of the lenses and the vitreal side of the retinas and stably expressed the transgenes for at least six weeks, the latest post-transplantation time point analyzed. Integration of donor cells into host retinas, ongoing proliferation of grafted cells or adverse effects of the donor cells on the morphology of the host eyes were not observed. Quantitative analyses of host retinas two, four and six weeks after cell transplantation revealed the presence of significantly more photoreceptor cells in eyes with grafted CNTF-NS cells than in eyes with grafted control-NS cells. This is the first demonstration that a continuous intraocular administration of a neurotrophic factor attenuates retinal degeneration in an animal model of neuronal ceroid lipofuscinosis.

Identification of a PRPF4 loss-of-function variant that abrogates U4/U6.U5 tri-snRNP integration and is associated with retinitis pigmentosa.

Pre-mRNA splicing by the spliceosome is an essential step in the maturation of nearly all human mRNAs. Mutations in six spliceosomal proteins, PRPF3, PRPF4, PRPF6, PRPF8, PRPF31 and SNRNP200, cause retinitis pigmentosa (RP), a disease characterized by progressive photoreceptor degeneration. All splicing factors linked to RP are constituents of the U4/U6.U5 tri-snRNP subunit of the spliceosome, suggesting that the compromised function of this particle may lead to RP. Here, we report the identification of the p.R192H variant of the tri-snRNP factor PRPF4 in a patient with RP. The mutation affects a highly conserved arginine residue that is crucial for PRPF4 function. Introduction of a corresponding mutation into the zebrafish homolog of PRPF4 resulted in a complete loss of function in vivo. A series of biochemical experiments suggested that p.R192H disrupts the binding interface between PRPF4 and its interactor PRPF3. This interferes with the ability of PRPF4 to integrate into the tri-snRNP, as shown in a human cell line and in zebrafish embryos. These data suggest that the p.R192H variant of PRPF4 represents a functional null allele. The resulting haploinsufficiency of PRPF4 compromises the function of the tri-snRNP, reinforcing the notion that this spliceosomal particle is of crucial importance in the physiology of the retina.

A child with night blindness: preventing serious symptoms of Refsum disease.

Refsum disease is a genetic progressive neurological disorder caused by neurotoxic phytanic acid, a nutritional component patients are unable to metabolize. Symptoms include retinopathy, polyneuropathy, ataxia, and deafness. They are variable and rarely recognized before adulthood. The authors report the case of a 14-year-old girl diagnosed because of night blindness. They treated her with a phytanic acid-poor diet and extracorporeal lipid apheresis. They used different methods over a 30-month period. Thereafter, the patient was treated with diet only. Membrane filtration and heparin-induced extracorporeal low-density lipoprotein precipitation apheresis were well tolerated. Withdrawal of phytanic acid was studied quantitatively. During a 5-year period, blood phytanic acid levels decreased to a noncritical range. The patient remained free of ophthalmological and neurological progression for a total observation of 12 years. Early diagnosis and effective measures to keep the phytanic acid load low can probably prevent the serious sequelae of Refsum disease. Developing a method for newborn screening is desirable.

Effects of the AMPA antagonist ZK 200775 on visual function: a randomized controlled trial.

BACKGROUND: ZK 200775 is an antagonist at the alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor and had earned attention as a possible neuroprotective agent in cerebral ischemia. Probands receiving the agent within phase I trials reported on an alteration of visual perception. In this trial, the effects of ZK 200775 on the visual system were analyzed in detail. METHODOLOGY: In a randomised controlled trial we examined eyes and vision before and after the intravenous administration of two different doses of ZK 200775 and placebo. There were 3 groups of 6 probands each: Group 1 recieved 0.03 mg/kg/h, group 2 0.75 mg/kg/h of ZK 200775, the control group received 0.9% sodium chloride solution. Probands were healthy males aged between 57 and 69 years. The following methods were applied: clinical examination, visual acuity, ophthalmoscopy, colour vision, rod absolute threshold, central visual field, pattern-reversal visual evoked potentials (pVEP), ON-OFF and full-field electroretinogram (ERG). PRINCIPAL FINDINGS: No effect of ZK 200775 was seen on eye position or motility, stereopsis, pupillary function or central visual field testing. Visual acuity and dark vision deteriorated significantly in both treated groups. Color vision was most remarkably impaired. The dark-adapted ERG revealed a reduction of oscillatory potentials (OP) and partly of the a- and b-wave, furthermore an alteration of b-wave morphology and an insignificantly elevated b/a-ratio. Cone-ERG modalities showed decreased amplitudes and delayed implicit times. In the ON-OFF ERG the ON-answer amplitudes increased whereas the peak times of the OFF-answer were reduced. The pattern VEP exhibited lower amplitudes and prolonged peak times. CONCLUSIONS: The AMPA receptor blockade led to a strong impairment of typical OFF-pathway functions like color vision and the cone ERG. On the other hand the ON-pathway as measured by dark vision and the scotopic ERG was affected as well. This further elucidates the interdependence of both pathways. TRIAL REGISTRATION: ClinicalTrials.gov NCT00999284.

Cone versus rod disease in a mutant Rpgr mouse caused by different genetic backgrounds.

PURPOSE: To establish mouse models for RPGR-associated diseases by generating and characterizing an Rpgr mutation (in-frame deletion of exon 4) in two different genetic backgrounds (BL/6 and BALB/c). METHODS: Gene targeting in embryonic stem (ES) cells was performed to introduce a in-frame deletion of exon 4 in the Rpgr gene (Rpgr(DeltaEx4)). Subsequently, the mutation was introduced in two different inbred mouse strains by successive breeding. Mutant and wild-type mice of both strains were characterized by electroretinography (ERG) and histology at five time points (1, 3, 6, 9, and 12 months). RPGR transcript amounts were assessed by quantitative RT-PCR. A variety of photoreceptor proteins, including RPGR-ORF15, RPGRIP, PDE6delta/PrBPdelta, rhodopsin, and cone opsin, were localized on retinal sections by immunohistochemistry. RESULTS: Mislocalization of rhodopsin and cone opsin was an early pathologic event in mutant mice of both lines. In contrast, RPGR-ORF15 as well as RPGRIP1 and PDE6delta/PrBPdelta showed similar localizations in mutant and wild-type animals. Functional and histologic studies revealed a mild rod-dominated phenotype in mutant male mice on the BL/6 background, whereas a cone-dominated phenotype was observed for the same mutation in the BALB/c background. CONCLUSIONS: Both Rpgr mutant mouse lines developed retinal disease with a striking effect of the genetic background. Cone-specific modifiers might influence the retinal phenotype in the BALB/c strain. The two lines provide models to study RPGR function in rods and cones, respectively.

Ocular syphilis--indicator of previously unknown HIV-infection.

OBJECTIVES: To detect the prevalence of HIV-co-infection in patients with ocular syphilis and to compare ocular syphilis in HIV-positive and -negative patients. METHODS: 24 consecutive patients treated for ocular syphilis at our hospital between 1998 and 2006 were evaluated retrospectively. Patients' characteristics, laboratory results (including syphilis serology, HIV status, CSF examination), major ophthalmologic finding, treatment and course were assessed. Data of HIV-positive and -negative patients were compared. RESULTS: Of the 24 patients with ocular syphilis, 11 were co-infected with HIV. Notably, the HIV-infection had previously been unknown in 7 of the 11 HIV-positive patients. 6 of these were in an early disease stage (CDC category A). Clinical and laboratory findings did not differ between HIV-positive and -negative patients except for the C-reactive protein (CRP), which was significantly higher in HIV-infected patients. CONCLUSIONS: Ocular syphilis led to new diagnosis of HIV-infection in an unexpectedly high number of patients, which emphasises that patients with ocular syphilis must be screened for HIV-co-infection. According to our study the expected benefit is high because most of the patients newly diagnosed with HIV had high CD4(+) cell counts. These patients can be monitored and treated before the development of AIDS.

Mutations in TOPORS: a rare cause of autosomal dominant retinitis pigmentosa in continental Europe?

Mutations in TOPORS cause autosomal dominant retinitis pigmentosa (adRP). Examination of 160 adRP patients from continental Europe revealed nine exonic single nucleotide variants, eight of which reside in the coding region; three synonymous single nucleotide polymorphisms (SNPs; c.2319T > C, c.2991T > C and c.1560A > G), three nonsynonymous SNPs (c.58C > T/p.P20S, c.74C >G/p.S25W and c.1730C > A/p.S577Y) and two novel missense mutations (c.1205A > C/p.Q402P and c.1818T > G/p.S606R). Whether the latter two variants represent adRP causing mutations awaits further analysis.