Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q00604 (X-linked)
 16,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

X-linked juvenile retinoschisis(RS) is a recessively inherited vitreo-retinal degeneration characterized by macular pathology and intraretinal splitting of the retina. The RS gene has been localized to Xp22.2 to an approximately 1 Mb interval between DXS418 and DXS999/DXS7161. Mapping and expression analysis of expressed sequence tags have identified a novel transcript, designated XLRS1, within the centromeric RS locus that is exclusively expressed in retina. The predicted XLRS1 protein contains a highly conserved motif implicated in cell-cell interaction and thus may be active in cell adhesion processes during retinal development. Mutational analyses of XLRS1 in affected individuals from nine unrelated RS families revealed one nonsense, one frameshift, one splice acceptor and six missense mutations segregating with the disease phenotype in the respective families. These data provide strong evidence that the XLRS1 gene, when mutated, causes RS.
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PMID:Positional cloning of the gene associated with X-linked juvenile retinoschisis. 932 35

Retinal photoreceptor cells are particularly vulnerable to degenerations that can eventually lead to blindness. Our purpose is to identify and characterize genes expressed specifically in photoreceptors in order to increase our understanding of the biochemistry and function of these cells, and then to use these genes as candidates for the sites of mutations responsible for degenerative retinal diseases. We have characterized a cDNA, a fragment of which (SR3.1) was originally isolated by subtractive hybridization of adult, photoreceptorless rd mouse retinal cDNAs from the cDNAs of normal mouse retina. The full-length sequence of this cDNA was determined from clones obtained by screening mouse retinal and eye cDNA libraries and by using the 5'- and 3'-RACE methods. Both Northern blot analysis and in situ hybridization showed that the corresponding mRNA is expressed in rod and cone photoreceptors. The gene encoding this cDNA was mapped to the X chromosome using an interspecific cross. Based on the nucleotide and amino acid sequences, as well as chromosome mapping, we determined that this gene is the mouse ortholog (Xlrs1) of the human X-linked juvenile retinoschisis gene (XLRS1). Analysis of the predicted amino acid sequence indicates that the Xlrs1 mRNA may encode a secretable, adhesion protein. Therefore, our data suggest that X-linked juvenile retinoschisis originates from abnormalities in a photoreceptor-derived adhesion protein.
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PMID:The mouse X-linked juvenile retinoschisis cDNA: expression in photoreceptors. 1002 77

Congenital retinoschisis (RS) is a hereditary eye disorder characterized by intraretinal schisis and central and peripheral retinal lesion. The gene responsible for the X-linked retinoschisis (XLRS1) has recently been isolated and found to contain mutations in affected members of several families. In this communication, two families with X-linked RS were analyzed for possible disease-causing mutations by polymerase chain reaction amplification of exons followed by DNA sequencing. Our analyses reveal a missense mutation at codon 197 in exon 6 and a nonsense mutation in exon-4 of XLRS1 gene. These changes resulted in the replacement of a highly conserved arginine by a cysteine residue and introduced a premature termination signal at codon 89, respectively. These mutations, which are transmitted through three generations, cosegregated with the disease, and are not found in the unaffected family members and 150 normal X-chromosomes, are likely to be pathogenic in these families.
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PMID:Recurrent missense (R197C) and nonsense (Y89X) mutations in the XLRS1 gene in families with X-linked retinoschisis. 1007 81

X-linked juvenile retinoschisis (RS) is a recessively inherited disorder causing progressive vitreoretinal degeneration in males. The gene defective in retinoschisis, XLRS1, has recently been identified and characterised. This gene consists of six exons encoding a protein with a putative role in cell-cell adhesion and phospholipid binding. Juvenile retinoschisis has been actively studied in Finland over the past 30 years, with over 300 diagnosed RS patients. Based on genealogical studies, approximately 70% of the Finnish RS patients originate from Western Finland and 20% from Northern Finland. In this study, one third of the known Finnish RS patients were screened for mutations of the XLRS1 gene. Haplotype analysis, using nine microsatellite markers spanning 1 cM in Xp22.2, suggested the segregation of eight different mutations in these families. To identify mutations, the six exons were amplified by PCR and analysed by single strand conformation analysis, followed by direct sequencing of the PCR products. We identified seven distinct missense mutations, all in exons 4 and 6. The mutations in exon 4, 214G > A and 221G > T, are accountable for RS in Western Finland. A third mutation in exon 4, 325G > C, gives rise to RS in Northern Finland. These three founder mutations are the predominant cause of RS in Finland and their existence explains the high incidence of the disease. The identification of mutations common in genetically isolated populations, such as Finland, allows the diagnosis of patients with an atypical RS phenotype and enables nationwide carrier testing and improved genetic counselling.
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PMID:Three widespread founder mutations contribute to high incidence of X-linked juvenile retinoschisis in Finland. 1023 14

X-linked juvenile retinoschisis is a form of vitreoretinal dystrophy that is characterized by foveal and peripheral splitting of the retinal nerve fiber layer. Pathognomonic of this disorder is a microcystic radiate appearance in the fovea. We encountered a 10 year-old, mildly retarded, Japanese boy, who exhibited a widely extended macular retinoschisis bilaterally. A break in the inner layer of the left eye mimicked a lamellar macular hole, which is a rare manifestation of the disease. Peripheral retinoschisis was absent. Only a few reports have described marked bilateral macular retinoschisis that involved entire posterior pole, while various other macular findings have been reported. This patient with a severe form of retinoschisis was found to harbor the deletion of 33 base pairs, including the boundary region of exon 3 and intron 3 in the XLRS1 gene.
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PMID:Severe juvenile retinoschisis associated with a 33-bps deletion in XLRS1 gene. 1045 24

To characterize the clinical features associated with XLRS1 gene mutations in Japanese patients with X-linked juvenile retinoschisis (xlRS), we evaluated the following data on 14 Japanese males from 13 unrelated families with XLRS1 mutations: age and symptoms at first visit to an ophthalmologist and ophthalmologic findings including visual acuity, refractive errors, fundoscopic appearance, and results of electroretinography (ERG) and electro-oculography (EOG). Each clinical finding was reviewed when the patients were between six and eight years of age. The best-corrected visual acuity in 12 patients (24 eyes) between the ages 6 and 8 years ranged from 1.0 to no light perception. Macular abnormalities were present in all cases. Peripheral retinoschisis was present in 14 of 26 eyes (53.8%). In the 21 eyes for which a single-flash ERG had been recorded, b-wave amplitude was reduced in 17 eyes. The EOG showed a low Arden ratio in three of the 13 eyes in the seven patients evaluated. No clear relationship was observed between the clinical features and the existing mutations. Three of four patients with a visual acuity less than 0.1 had retinal detachment or severe macular lesion that had occurred before the age of four years. Two patients harbored deletions of exon 1 or of the boundary region between exon 3 and intron 3, and one patient harbored R182C in exon 6. The present study shows a heterogeneity of mutations in the XLRS1 gene and phenotypic variations in 14 Japanese patients with xlRS.
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PMID:Clinical characteristics of 14 japanese patients with X-linked juvenile retinoschisis associated with XLRS1 mutation. 1103 49

Macular degeneration is a leading cause of blindness that affects the aged population. The complexity of the molecular basis of macular disease is now beginning to be elucidated with the identification of disease-causing genes. For example, mutations in the ABCR gene, (recently identified in cones as well) which codes for retinal rod-specific ABCR protein is responsible for Stargardt macular dystrophy/fundus flavimaculatus, an autosomal recessive macular dystrophy with juvenile onset, which accounts for 7% of human retinal degenerative diseases. The gene mutant in X-linked juvenile retinoschisis, XLRS1, is the first macular dystrophy gene to be isolated by positional cloning. Mutations in the peripherin/RDS gene have been shown to be associated with a variety of distinct forms of macular degenerations. The tissue inhibitor of metalloproteinase 3 (TIMP3) is implicated in autosomal dominant Sorsby fundus dystrophy. Best vitelliform macular dystrophy was mapped to 11q12-q13. The cloned gene product is the protein bestrophin, which is a retinal specific gene expressed in the RPE and possibly involved in the metabolism and transport of polyunsaturated fatty acids. The cloning of genes for rare heritable forms of macular degeneration will increase our understanding of the basic pathogenesis of the disease process. In the future this should also allow us to test the hypothesis that the coincidence of subclinical mutations in a number of genes involved in the formation and function of the macula can be responsible for cases of age-related macula-degeneration which is by far the most common form of these macular disorders.
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PMID:Molecular genetics of macular degeneration. 1155 84

We examined the XLRS1 gene for mutations in 6 Japanese patients with X-linked juvenile retinoschisis from a total of three families (5 males and 1 female), and from 3 obligate carrier females. DNA was amplified for all six coding exons of the XLRS1 gene with established primer pairs, and was sequenced directly. Each family had a different mutation, Trp96stop, 522+1g-->a, and Lys167Asn in the XLRS1 gene. Affected patients had a hemizygous mutant allele while the obligate carrier females were heterozygotes who had both wild-type and mutant-type alleles. A proband female, who was the offspring of asymptomatic and nonconsanguineous parents, was found to have a chromosomal karyotype (45, X) that was indicative of Turner's syndrome. These three different mutations in the XLRS1 gene have not been previously reported. Further studies are needed to determine the relationship between these defects in the XLRS1 gene and the phenotypic expression of the disease.
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PMID:Three novel mutations in the X-linked juvenile retinoschisis (XLRS1) gene in 6 Japanese patients, 1 of whom had Turner's syndrome. 1292 Mar 43

X-linked juvenile retinoschisis is a rare progressive vitreoretinal degenerative process that appears in early childhood, results in decreased visual acuity and blindness (if severe), and is caused by various mutations within the XLRS1 gene at Xp22.2. We report an affected family of Western European ancestry with X-linked juvenile retinoschisis. The family was found to carry a 304C-->T substitution in exon 4 of the XLRS1 gene, resulting in an Arg102Trp amino acid substitution. Two of the four available clinical cases in this family were found to carry the mutation. All available mothers of affected males were found to be unaffected carriers of the mutation, a typical feature of X-linked diseases. Two new female carriers, sisters of affected males, were identified and counseled accordingly. Questionnaires on visual functioning were given to the affected family members to examine the psychologic and sociologic impact of X-linked juvenile retinoschisis, which documented an associated stigma even when affected with a "mild" phenotype.
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PMID:Unusual phenotypic expression of an XLRS1 mutation in X-linked juvenile retinoschisis. 1690 Sep 31

ABSTRACT X-linked juvenile retinoschisis is a rare progressive vitreoretinal degenerative process that appears in early childhood, results in decreased visual acuity and blindness (if severe), and is caused by various mutations within the XLRS1 gene at Xp22.2. We report an affected family of Western European ancestry with X-linked juvenile retinoschisis. The family was found to carry a 304C-->T substitution in exon 4 of the XLRS1 gene, resulting in an Arg102Trp amino acid substitution. Two of the four available clinical cases in this family were found to carry the mutation. All available mothers of affected males were found to be unaffected carriers of the mutation, a typical feature of X-linked diseases. Two new female carriers, sisters of affected males, were identified and counseled accordingly. Questionnaires on visual functioning were given to the affected family members to examine the psychologic and sociologic impact of X-linked juvenile retinoschisis, which documented an associated stigma even when affected with a "mild" phenotype. (J Child Neurol 2006;21:331-333; DOI 10.2310/7010.2006.00085).
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PMID:Unusual Phenotypic Expression of an XLRS1 Mutation in X-Linked Juvenile Retinoschisis. 1690 36


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