Papers by Francesca Simonelli
PloS one, 2017
To develop and validate a tool aiming to support ophthalmologists in identifying, during routine ... more To develop and validate a tool aiming to support ophthalmologists in identifying, during routine ophthalmologic visits, patients at higher risk of falling in the following year. A group of 141 subjects (age: 73.2 ± 11.4 years), recruited at our Eye Clinic, underwent a baseline ophthalmic examination and a standardized questionnaire, including lifestyles, general health, social engagement and eyesight problems. Moreover, visual disability was assessed by the Activity of Daily Vision Scale (ADVS). The subjects were followed up for 12 months in order to record prospective falls. A subject who reported at least one fall within one year from the baseline assessment was considered as faller, otherwise as non-faller. Different tree-based algorithms (i.e., C4.5, AdaBoost and Random Forests) were used to develop automatic classifiers and their performances were evaluated by the cross-validation approach. Over the follow-up, 25 falls were referred by 13 patients. The logistic regression analy...
Investigative ophthalmology & visual science, 2000
To assess the mutation spectrum in the ABCR gene and clinical phenotypes in Italian families with... more To assess the mutation spectrum in the ABCR gene and clinical phenotypes in Italian families with autosomal recessive Stargardt disease (STGD1) and fundus flavimaculatus (FFM). Eleven families from southern Italy, including 18 patients with diagnoses of STGD1, were clinically examined. Ophthalmologic examination included kinetic perimetry, electrophysiological studies, and fluorescein angiography. DNA samples of the affected individuals and their family members were analyzed for variants in all 50 exons of the ABCR gene by a combination of single-strand conformation polymorphism analysis and direct sequencing techniques. TenABCR variants were identified in 16 (73%) of 22 mutant alleles of patients with STGD1. Five mutations of 10 that were found had not been previously described. The majority of variants represent missense amino acid substitutions, and all mutant alleles cosegregate with the disease in the respective families. These ABCR variants were not detected in 170 unaffected ...
Bollettino della Società italiana di biologia sperimentale, 1990
The activity of galactokinase in red blood cells, has been assayed in 17 patients with idiopathic... more The activity of galactokinase in red blood cells, has been assayed in 17 patients with idiopathic senile and presenile cataract and in 12 age-matched subjects with perfectly transparent lenses. 3 of the idiopathic cataract patients (17.6%) showed low erythrocytes GK activity, while nobody in the control group showed reduced GK activity. Although preliminary, our results seem to support the possibility that a chronic disorder of galactose metabolism may be involved in the pathogenesis of the idiopathic senile and presenile cataract.
Metabolic, pediatric, and systemic ophthalmology (New York, N.Y. : 1985), 1992
The activity of galactokinase in red blood cells of 30 patients affected by idiophatic presenile ... more The activity of galactokinase in red blood cells of 30 patients affected by idiophatic presenile and senile cataract, and of 20 age-matched controls with perfectly transparent lenses, was investigated. The results obtained show a partial deficiency of the galactokinase activity in the patients affected by presenile idiopathic cataract. There is, moreover, a significant relationship between the cortical form of cataract and enzymatic reduction.
Molecular vision, 2011
Usher syndrome is an autosomal recessive disorder characterized by hearing and vision loss. Usher... more Usher syndrome is an autosomal recessive disorder characterized by hearing and vision loss. Usher syndrome is divided into three clinical subclasses (type 1, type 2, and type 3), which differ in terms of the severity and progression of hearing loss and the presence or absence of vestibular symptoms. Usher syndrome is defined by significant genetic heterogeneity, with at least 12 distinct loci described and 9 genes identified. This study aims to provide a molecular epidemiology report of Usher syndrome in Italy. Molecular data have been obtained on 75 unrelated Italian patients using the most up-to date technology available for the screening of Usher syndrome gene mutations, i.e., the genotyping microarray developed by Asper Biotech (Tartu, Estonia), which simultaneously investigates 612 different marker positions using the well established arrayed primer extension methodology (APEX). Using this method, we found that 12% of cases (9 out of 75) harbored homozygous or compound heterozy...
Seminars in Ophthalmology, 2013
Multiple studies have shown that genetic factors may play an important role in determining an ind... more Multiple studies have shown that genetic factors may play an important role in determining an individual's risk for the development of diabetic retinopathy (DR) and progression to proliferative DR. However, consistent and definitive genetic associations with DR across broad populations have been not been established. Numerous genes have been studied for their association with DR and the results of these investigations have most specifically pointed to three specific genes that are likely involved in DR development and progression. The gene coding for vascular endothelial growth factor, aldose reductase, and the receptor for advanced glycation end products have been extensively evaluated, and specific polymorphisms of these genes have been suggested to potentially increase the risk of DR development. In this paper, we have reviewed the published literature on the genetics of DR and the potential implications for DR development and progression.
Orphanet Journal of Rare Diseases, 2013
Background Inherited retinal dystrophies, including Retinitis Pigmentosa and Leber Congenital Ama... more Background Inherited retinal dystrophies, including Retinitis Pigmentosa and Leber Congenital Amaurosis among others, are a group of genetically heterogeneous disorders that lead to variable degrees of visual deficits. They can be caused by mutations in over 100 genes and there is evidence for the presence of as yet unidentified genes in a significant proportion of patients. We aimed at identifying a novel gene for an autosomal recessive form of early onset severe retinal dystrophy in a patient carrying no previously described mutations in known genes. Methods An integrated strategy including homozygosity mapping and whole exome sequencing was used to identify the responsible mutation. Functional tests were performed in the medaka fish (Oryzias latipes) model organism to gain further insight into the pathogenic role of the ADAMTS18 gene in eye and central nervous system (CNS) dysfunction. Results This study identified, in the analyzed patient, a homozygous missense mutation in the A...
Ophthalmic Research, 2005
Autosomal recessive Stargardt disease (STGD) has been associated with substantial genetic and phe... more Autosomal recessive Stargardt disease (STGD) has been associated with substantial genetic and phenotypic heterogeneity. By systematic clinical analyses of STGD patients with complete genetic data (i.e. identified mutations on both alleles of the ABCA4 gene), we set out to determine phenotypic subtypes and to correlate these with specific ABCA4 alleles. Twenty-eight patients from 18 families with STGD/fundus flavimaculatus were investigated. All patients were submitted to complete ophthalmologic examination, electrophysiology, fluorescein angiography and ABCA4 gene chip analysis. Two main clinical phenotypes were observed among the examined patients. The severe phenotype was characterized by the onset of the disease <20 years and reduced ERG response, whereas the mild phenotype presented with later onset of the disease and a normal ERG response. Genetic analysis of the ABCA4 gene revealed, in the severe group, more frequently deletions, stop codons and insertions as compared to th...
Ophthalmic Research, 2001
Objective: Apolipoprotein E (apoE) is an important regulator of cholesterol and lipid transport d... more Objective: Apolipoprotein E (apoE) is an important regulator of cholesterol and lipid transport during compensatory synaptogenesis. Our purpose was to investigate the role of apoE gene polymorphisms in Italian patients with age-related macular degeneration (AMD). Methods: We used the polymerase chain reaction technique to analyze apoE genotypes in 87 patients with AMD, in 47 age-matched controls and in 1,287 individuals from a general reference population. Results: The frequency of allele Ε4 carriers was significantly higher (p = 0.002) in the general population than in AMD patients, while the frequency of allele Ε2 was higher in the patients (p = 0.069) with an increased risk for AMD in the patients versus the population-based controls (odds ratio = 1.7; 95% confidence interval: 1.0–2.9). Allele Ε4 was associated with a decreased risk for AMD in the patients versus the population-based controls (odds ratio = 0.3; 95% confidence interval: 0.1–0.8). Clinical Relevance: These data sug...
Ophthalmic Research, 2004
Genetic variation in the ABCA4 (ABCR) gene has been associated with several distinct retinal phen... more Genetic variation in the ABCA4 (ABCR) gene has been associated with several distinct retinal phenotypes, including Stargardt disease/fundus flavimaculatus (STGD/FFM), cone-rod dystrophy (CRD), retinitis pigmentosa (RP) and age-related macular degeneration. The current model of genotype/phenotype association suggests that patients harboring deleterious mutations in both ABCR alleles would develop RP-like retinal pathology. Here we describe ABCA4-associated phenotypes, including a proband with a homozygous nonsense mutation in a family from Southern Italy. The proband had been originally diagnosed with STGD. Ophthalmologic examination included kinetic perimetry, electrophysiological studies and fluorescein angiography. DNA of the affected individual and family members was analyzed for variants in all 50 exons of the ABCA4 gene by screening on the ABCR400 microarray. A homozygous nonsense mutation 2971G>T (G991X) was detected in a patient initially diagnosed with STGD based on fundu...
New England Journal of Medicine, 2008
Journal of Medical Genetics, 2005
Journal Français d'Ophtalmologie, 2005
Investigative Opthalmology & Visual Science, 2011
Experimental Eye Research, 1990
British Journal of Ophthalmology, 2005
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Papers by Francesca Simonelli