Search results for " pigmento"
showing 10 items of 100 documents
Homozygous variants in the gene SCAPER cause syndromic intellectual disability
2019
The S-Phase Cyclin A Associated Protein In The ER (SCAPER) gene is a ubiquitously expressed gene with unknown function in the brain. Recently, biallelic SCAPER variants were described in four patients from three families with retinitis pigmentosa (RP) and intellectual disability (ID). Here, we expand the spectrum of pathogenic variants in SCAPER and report on 10 further patients from four families with ID, RP, and additional dysmorphic features carrying homozygous variants in SCAPER. The variants found comprise frameshift, nonsense, and missense variants as well as an intragenic homozygous deletion, which spans SCAPER exons 15 and 16 and introduces a frameshift and a premature stop codon. A…
Phenotypical features of two patients diagnosed with PHARC syndrome and carriers of a new homozygous mutation in the ABHD12 gene.
2018
Abstract PHARC (Polyneuropathy, Hearing loss, Ataxia, Retinitis pigmentosa and Cataracts) (MIM# 612674 ) is an autosomal recessive neurodegenerative disease caused by mutations in the ABHD12 gene. We evaluated two Spanish siblings affected with pes cavus, sensorimotor neuropathy, hearing loss, retinitis pigmentosa and juvenile cataracts in whom the genetic test of ABHD12 revealed a novel homozygous frameshift mutation, c.211_223del (p.Arg71Tyrfs*26). The earliest clinical manifestation in these patients was a demyelinating neuropathy manifested with a Charcot-Marie-Tooth phenotype over three decades. Progressive hearing loss, cataracts and retinitis pigmentosa appeared after the age of 30. …
Mutations in ARL2BP, Encoding ADP-Ribosylation-Factor-Like 2 Binding Protein, Cause Autosomal-Recessive Retinitis Pigmentosa
2013
Retinitis pigmentosa (RP) is a genetically heterogeneous retinal degeneration characterized by photoreceptor death, which results in visual failure. Here, we used a combination of homozygosity mapping and exome sequencing to identify mutations in ARL2BP, which encodes an effector protein of the small GTPases ARL2 and ARL3, as causative for autosomal-recessive RP (RP66). In a family affected by RP and situs inversus, a homozygous, splice-acceptor mutation, c.101−1G>C, which alters pre-mRNA splicing of ARLBP2 in blood RNA, was identified. In another family, a homozygous c.134T>G (p.Met45Arg) mutation was identified. In the mouse retina, ARL2BP localized to the basal body and cilium-associated…
Gly114Asp mutation of rhodopsin in autosomal dominant retinitis pigmentosa
1995
Two autosomal dominant retinitis pigmentosa families of different origin were screened for rhodopsin mutations using the method of single strand conformation polymorphism and direct sequencing. We found a CGG-CAG substitution in codon 114 of rhodopsin in both families. This change predicted the replacement of a glycine by an aspartic acid and suggested that this change is the cause of the disease in these families.
Mutational screening of the USH2A gene in Spanish USH patients reveals 23 novel pathogenic mutations
2011
Abstract Background Usher Syndrome type II (USH2) is an autosomal recessive disorder, characterized by moderate to severe hearing impairment and retinitis pigmentosa (RP). Among the three genes implicated, mutations in the USH2A gene account for 74-90% of the USH2 cases. Methods To identify the genetic cause of the disease and determine the frequency of USH2A mutations in a cohort of 88 unrelated USH Spanish patients, we carried out a mutation screening of the 72 coding exons of this gene by direct sequencing. Moreover, we performed functional minigene studies for those changes that were predicted to affect splicing. Results As a result, a total of 144 DNA sequence variants were identified.…
Aqueous Humor Levels of Vascular Endothelial Growth Factor in Retinitis Pigmentosa
2008
PURPOSE To determine the level of vascular endothelial growth factor A (VEGF-A) in aqueous humors of patients with retinitis pigmentosa (RP). METHODS A prospective, comparative control study. Aqueous humor was collected from 16 eyes of 16 patients with RP. The level of VEGF-A was determined with a commercially available enzyme-linked immunosorbent assay kit. The control group comprised 16 aqueous samples from 16 patients about to undergo cataract surgery and without any other ocular or systemic diseases. RESULTS The concentration of VEGF-A in aqueous humor was markedly lower in patients with RP than in control subjects (Mann-Whitney U test, P < 0.001). The level of VEGF-A was 94.9 +/- 99.8 …
Methodological Aspects of the Application of the Naka-Rushton Equation to Clinical Electroretinogram
1993
The nonlinear relation between stimulus intensity and response amplitude of the electroretinogram (ERG) scotopic b wave can be described by a curve based on the Naka-Rushton (NR) equation. Up to now, the NR equation has been used to assess the features of the normal and pathological ERG, but the best approach for a correct evaluation of the parameters is still debatable. The parameters are thought to be related to the different conditions of retinal activities. The method is well known in experimental laboratories but is quite unusual at the clinical level. In the present paper the derivative analysis of the NR function is proposed as an easier approach to understand the variations of the N…
Different patterns of in vivo pro-oxidant states in a set of cancer- or aging-related genetic diseases
2008
A comparative evaluation is reported of pro-oxidant states in 82 patients with ataxia telangectasia (AT), Bloom syndrome (BS), Down syndrome (DS), Fanconi anemia (FA), Werner syndrome (WS), and xeroderma pigmentosum (XP) vs 98 control donors. These disorders display cancer proneness, and/or early aging, and/or other clinical features. The measured analytes were: (a) leukocyte and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), (b) blood glutathione (GSSG and GSH), (c) plasma glyoxal (Glx) and methylglyoxal (MGlx), and (d) some plasma antioxidants [uric acid (UA) and ascorbic acid (AA)]. Leukocyte 8-OHdG levels ranked as follows: WS>BS approximately FA approximately XP>DS approximately AT appr…
Lower lip squamous cell carcinoma in patients with photosensitive disorders : analysis of cases treated at the Brazilian National Cancer Institute (I…
2017
Background Lower lip squamous cell carcinoma (LLSCC) is a common malignancy of the head and neck, being mainly a consequence of a chronic exposure to ultraviolet (UV) light solar radiation. Here, we evaluated the clinicopathological profile of patients with photosensitive disorders (xeroderma pigmentosum, lupus erythematosus and albinism) that developed LLSCC. Material and Methods Data from patients who had a diagnosed LLSCC with a prior xeroderma pigmentosum, lupus erythematosus or albinism diagnosis that were treated at INCA from 1999 to 2012 were collected from patients’ medical records (n=16). The control group was composed of 68 patients with LLSCC without a medical history of photosen…
Prenatal diagnosis of a rhodopsin mutation using chemical cleavage of the mismatch
2002
Objective: Mutations of the rhodopsin gene are responsible for autosomal dominant or recessive retinitis pigmentosa (RP). The present study reports the first prenatal diagnosis performed on chorionic villi biopsy of a pregnant woman affected by a severe form of autosomal dominant transmitted RP, due to the Arg135Trp substitution. Methods: The rhodopsin gene was analysed by automated direct sequencing and, for the first time, by fluorescence-assisted mismatch analysis (FAMA). The latter is an inexpensive, rapid and particularly sensitive method, based on the chemical cleavage of the mismatch in heteroduplex DNA molecules marked with strand-specific fluorophores. Results: FAMA is a feasible p…