Ocular and extra-ocular features of patients with Leber congenital amaurosis and mutations in CEP290

Contains fulltext : 108895.pdf (publisher's version ) (Open Access)PURPOSE: This study investigated the centrosomal protein, 290-KD (CEP290) associated genotype and ocular and extra-ocular phenotype in 18 patients with Leber congenital amaurosis (LCA). METHODS: Eighteen patients with LCA from 14 families with mutations in the CEP290 gene were identified with sequencing or with heteroduplex analysis. Ophthalmic examinations were performed on all patients. Scans of the central nervous system were reassessed in three patients and obtained in two. Renal function was evaluated in all patients. Ultrasonography of the kidneys was performed in six patients. RESULTS: Eight patients (from five families) carried the c.2991+1655A>G mutation homozygously. Nine solitary patients carried this variant combined with a nonsense, frameshift, or splice site mutation on the second allele. One new nonsense mutation was identified: c.1078C>T. Fourteen patients (from 12 families) had been completely blind from birth or had light perception. The best-recorded visual acuity was 20/200. Peripheral fundus changes appeared to be progressive with a relatively preserved posterior pole. Novel ophthalmic features for the CEP290 phenotype were Coats-like exudative vasculopathy in two patients, a small chorioretinal coloboma in one patient, and well defined, small, atrophic spots at the level of the retinal pigment epithelium causing a dot-like appearance in five patients. Some CEP290 patients exhibited systemic abnormalities. We found abnormal proprioception in two patients and mild mental retardation in one. One patient was infertile due to immobile spermatozoa. No renal abnormalities were detected. CONCLUSIONS: CEP290-associated LCA has a severe, progressive, and clinically identifiable phenotype. Distinct extra-ocular findings were noted, which may be attributed to ciliary dysfunction

Disruption of the basal body protein POC1B results in autosomal-recessive cone-rod dystrophy

Exome sequencing revealed a homozygous missense mutation (c.317C>G [p.Arg106Pro]) in POC1B, encoding POC1 centriolar protein B, in three siblings with autosomal-recessive cone dystrophy or cone-rod dystrophy and compound-heterozygous POC1B mutations (c.199_201del [p.G1n67del] and c.810+1G>T) in an unrelated person with cone-rod dystrophy. Upon overexpression of POC1B in human TERT-immortalized retinal pigment epithelium 1 cells, the encoded wild-type protein localized to the basal body of the primary cilium, whereas this localization was lost for p.Arg106Pro and p.G1n67del variant forms of POC1B. Morpholino-oligonucleotide-induced knockdown of poc1b translation in zebrafish resulted in a dose-dependent small-eye phenotype, impaired optokinetic responses, and decreased length of photoreceptor outer segments. These ocular phenotypes could partially be rescued by wild-type human POC1B mRNA, but not by c.199_201del and c.317C>G mutant human POC1B mRNAs. Yeast two-hybrid screening of a human retinal cDNA library revealed FAM161A as a binary interaction partner of POC1B. This was confirmed in coimmunoprecipitation and colocalization assays, which both showed loss of FAM161A interaction with p.Arg106Pro and p.G1n67del variant forms of POC1B. FAM161A was previously implicated in autosomal-recessive retinitis pigmentosa and shown to be located at the base of the photoreceptor connecting cilium, where it interacts with several other ciliopathy-associated proteins. Altogether, this study demonstrates that POC1B mutations result in a defect of the photoreceptor sensory cilium and thus affect cone and rod photoreceptors

Heparanase Levels Are Elevated in the Urine and Plasma of Type 2 Diabetes Patients and Associate with Blood Glucose Levels

Heparanase is an endoglycosidase that specifically cleaves heparan sulfate side chains of heparan sulfate proteoglycans. Utilizing an ELISA method capable of detection and quantification of heparanase, we examined heparanase levels in the plasma and urine of a cohort of 29 patients diagnosed with type 2 diabetes mellitus (T2DM), 14 T2DM patients who underwent kidney transplantation, and 47 healthy volunteers. We provide evidence that heparanase levels in the urine of T2DM patients are markedly elevated compared to healthy controls (1162±181 vs. 156±29.6 pg/ml for T2DM and healthy controls, respectively), increase that is statistically highly significant (P<0.0001). Notably, heparanase levels were appreciably decreased in the urine of T2DM patients who underwent kidney transplantation, albeit remained still higher than healthy individuals (P<0.0001). Increased heparanase levels were also found in the plasma of T2DM patients. Importantly, urine heparanase was associated with elevated blood glucose levels, implying that glucose mediates heparanase upregulation and secretion into the urine and blood. Utilizing an in vitro system, we show that insulin stimulates heparanase secretion by kidney 293 cells, and even higher secretion is observed when insulin is added to cells maintained under high glucose conditions. These results provide evidence for a significant involvement of heparanase in diabetic complications

Development of a wind gust model to estimate gust speeds and their return periods

Spatially dense observations of gust speeds are necessary for various applications, but their availability is limited in space and time. This work presents an approach to help to overcome this problem. The main objective is the generation of synthetic wind gust velocities. With this aim, theoretical wind and gust distributions are estimated from 10 yr of hourly observations collected at 123 synoptic weather stations provided by the German Weather Service. As pre-processing, an exposure correction is applied on measurements of the mean wind velocity to reduce the influence of local urban and topographic effects. The wind gust model is built as a transfer function between distribution parameters of wind and gust velocities. The aim of this procedure is to estimate the parameters of gusts at stations where only wind speed data is available. These parameters can be used to generate synthetic gusts, which can improve the accuracy of return periods at test sites with a lack of observations. The second objective is to determine return periods much longer than the nominal length of the original time series by considering extreme value statistics. Estimates for both local maximum return periods and average return periods for single historical events are provided. The comparison of maximum and average return periods shows that even storms with short average return periods may lead to local wind gusts with return periods of several decades. Despite uncertainties caused by the short length of the observational records, the method leads to consistent results, enabling a wide range of possible applications

Disruption of the Basal Body Protein POC1B Results in Autosomal-Recessive Cone-Rod Dystrophy

Exome sequencing revealed a homozygous missense mutation (c.317C>G [p.Arg106Pro]) in POC1B, encoding POC1 centriolar protein B, in three siblings with autosomal-recessive cone dystrophy or cone-rod dystrophy and compound-heterozygous POC1B mutations (c.199_201del [p.Gln67del] and c.810+1G>T) in an unrelated person with cone-rod dystrophy. Upon overexpression of POC1B in human TERT-immortalized retinal pigment epithelium 1 cells, the encoded wild-type protein localized to the basal body of the primary cilium, whereas this localization was lost for p.Arg106Pro and p.Gln67del variant forms of POC1B. Morpholino-oligonucleotide-induced knockdown of poc1b translation in zebrafish resulted in a dose-dependent small-eye phenotype, impaired optokinetic responses, and decreased length of photoreceptor outer segments. These ocular phenotypes could partially be rescued by wild-type human POC1B mRNA, but not by c.199_201del and c.317C>G mutant human POC1B mRNAs. Yeast two-hybrid screening of a human retinal cDNA library revealed FAM161A as a binary interaction partner of POC1B. This was confirmed in coimmunoprecipitation and colocalization assays, which both showed loss of FAM161A interaction with p.Arg106Pro and p.Gln67del variant forms of POC1B. FAM161A was previously implicated in autosomal-recessive retinitis pigmentosa and shown to be located at the base of the photoreceptor connecting cilium, where it interacts with several other ciliopathy-associated proteins. Altogether, this study demonstrates that POC1B mutations result in a defect of the photoreceptor sensory cilium and thus affect cone and rod photoreceptors

The Natural History of Leber Congenital Amaurosis and Cone-Rod Dystrophy Associated with Variants in the GUCY2D Gene

OBJECTIVE: To describe the spectrum of Leber congenital amaurosis (LCA) and cone-rod dystrophy (CORD) associated with the GUCY2D gene, and to identify potential clinical endpoints and optimal patient selection for future therapeutic trials. DESIGN: International multicenter retrospective cohort study. SUBJECTS: 82 patients with GUCY2D-associated CORD and LCA from 54 molecularly confirmed families. METHODS: Data were gathered by reviewing medical records for medical history, symptoms, best-corrected visual acuity (BCVA), ophthalmoscopy, visual fields, full-field electroretinography and retinal imaging (fundus photography, spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence). MAIN OUTCOMES MEASURES: Age of onset, annual decline of visual acuity, estimated visual impairment per age, genotype-phenotype correlations, anatomic characteristics on funduscopy, and multimodal imaging. RESULTS: Fourteen patients with autosomal recessive LCA and 68 with autosomal dominant CORD were included. The median follow-up time was 5.2 years (interquartile range (IQR), 2.6-8.8) for LCA, and 7.2 years (IQR, 2.2-14.2) for CORD. Generally, LCA presented in the first year of life. The BCVA in LCA ranged from no light perception to 1.00 logMAR, and remained relatively stable during follow-up. Imaging for LCA was limited, but showed little to no structural degeneration. In CORD, progressive vision loss started around the second decade of life. The annual decline rate of visual acuity was 0.022 logMAR (P A and the c.2512C>T GUCY2D variant (P = 0.798). At the age of 40 years the probability of being blind or severely visually impaired was 32%. The integrity of the ellipsoid zone (EZ) and external limiting membrane (ELM) on SD-OCT were correlated significantly with BCVA (Spearman's ρ = 0.744, P = 0.001 and ρ = 0.712, P < 0.001, respectively) in CORD. CONCLUSION: LCA due to variants in GUCY2D results in severe congenital visual impairment with relatively intact macular anatomy on funduscopy and available imaging, suggesting a long preservation of photoreceptors. Despite large variability, GUCY2D-associated CORD generally presented during adolescence with a progressive loss of vision and culminated in severe visual impairment during mid to late-adulthood. The integrity of the ELM and EZ may be suitable structural endpoints for therapeutic studies in GUCY2D-associated CORD

Clinical course of cone dystrophy caused by mutations in the RPGR gene

Contains fulltext : 97720.pdf (publisher's version ) (Closed access)BACKGROUND: Mutations in the RPGR gene predominantly cause rod photoreceptor disorders with a large variability in clinical course. In this report, we describe two families with mutations in this gene and cone involvement. METHODS: We investigated an X-linked cone dystrophy family (1) with 25 affected males, 25 female carriers, and 21 non-carriers, as well as a small family (2) with one affected and one unaffected male. The RPGR gene was analyzed by direct sequencing. All medical records were evaluated, and all available data on visual acuity, color vision testing, ophthalmoscopy, fundus photography, fundus autofluorescence, Goldmann perimetry, SD-OCT, dark adaptation, and full-field electroretinography (ERG) were registered. Cumulative risks of visual loss were studied with Kaplan-Meier product-limit survival analysis. RESULTS: Both families had a frameshift mutation in ORF15 of the RPGR gene; family 1 had p.Ser1107ValfsX4, and family 2 had p.His1100GlnfsX10. Mean follow up was 13 years (SD 10). Virtually all affected males showed reduced photopic and normal scotopic responses on ERG. Fifty percent of the patients had a visual acuity of <0.5 at age 35 years (SE 2.2), and 75% of the patients was legally blind at age 60 years (SE 2.3). Female carriers showed no signs of ocular involvement. CONCLUSIONS: This report describes the clinical course and visual prognosis in two families with cone dystrophy due to RPGR mutations in the 3' terminal region of ORF15. Remarkable features were the consistent, late-onset phenotype, the severe visual outcome, and the non-expression in female carriers. Expression of RPGR mutations in this particular region appears to be relatively homogeneous and predisposed to cones