Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Aniridia”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1988

Two anonymous DNA segments distinguish the Wilms' tumor and aniridia loci.

The association of Wilms' tumor with aniridia (the WAGR complex) in children with 11p13 chromosomal abnormalities has been established, but the paucity of molecular probes in 11p13 has hampered identification of the responsible genes. Two new anonymous DNA segments have been identified that map to the WAGR region of 11p13. Both DNA probes identify a cytologically undetectable deletion associated with a balanced chromosome translocation inherited by a patient with familial aniridia, but not Wilms' tumor. The same two DNA segments are also included in the distal p13-p14.1 deletion of another patient, who has aniridia, Wilms' tumor, and hypogonadism, but they are not included in the p12-p13 deletion of a third patient, who does not have aniridia but has had a Wilms' tumor. The discovery of this aniridia deletion and these two DNA segments that physically separate the Wilms' tumor and aniridia loci should facilitate identification of the genes in the WAGR locus, beginning with the aniridia gene.

Animals↗
PubMed1995

Aniridia: recent achievements in paediatric practice.

Aniridia is a rare panocular disorder which primarily involves not only the iris, but also the retina, optic nerve, lens and cornea. Visual acuity deteriorates as a result of nystagmus, glaucoma, cataract, corneal opacities and retinal hypoplasia. Aniridia may appear as an isolated disorder, most often familial with autosomal dominance or sporadically in association with at least 12 syndromes. Both familial isolated and Wilms tumour, bilateral sporadic aniridia, genitourinary abnormalities and mental retardation syndrome-associated aniridia have been traced to a mutation of the PAX6 gene on band 11p13. Since genetic diagnosis of this disorder is already possible, counselling affected families should be preceded by karyotype studies and linkage analysis in familial cases of isolated aniridia. In sporadic cases of isolated aniridia or WAGR syndrome, we suggest that PAX6 mutation analysis be employed.

Aniridia↗
PubMed1998

[Molecular genetic study of the PAX6 gene in aniridia patients].

INTRODUCTION: Aniridia represents a congenital ocular disorder with partial or complete iris hypoplasia. The disorder is associated with poor vision, glaucoma, corneal and lenticular opacities, ectopia lentis due to abnormal zonula fibers, as well as optic nerve and macular abnormalities. Aniridia may present as either hereditary or sporadic cases. Some of the sporadic cases develop Wilms' tumor, frequently as part of the WAGR syndrome (Wilms' tumor, aniridia, genitourinary abnormalities and mental retardation). PAX6, a candidate gene located on chromosome 11p13, is often mutated in aniridia patients. The gene encodes a transcription regulatory protein. METHOD: Analysis of the PAX6 gene was done using PCR (polymerase chain reaction), SSCP (single strand conformation polymorphism) and DNA sequencing. RESULTS: In 13 of 20 aniridia patients a PAX6 gene mutation was found. CONCLUSION: The mutations result in a gene product with reduced function or a reduced PAX6 protein level. Molecular analysis of aniridia is also a valuable diagnostic tool for Wilms' tumor risk evaluation, as patients with proven PAX6 mutations--in contrast to cases with large deletions of the 11p13 region--are at no increased risk to develop Wilms' tumor.

Aniridia↗
PubMed2005

Association of aniridia and dry eyes.

PURPOSE: To study the association between congenital aniridia and dry eyes, and the status of limbal stem cells. DESIGN: Single-center, retrospective, noninterventional, comparative case series. PARTICIPANTS: Twenty patients (36 eyes) diagnosed with congenital aniridia. METHODS: Retrospective review of medical records at the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia to identify all cases of congenital aniridia. Selected patients were requested to undergo further testing, especially for evaluation of dry eyes. Full ocular examinations were performed, including examination of the meibomian gland orifices and dry eye evaluation (by predetermined criteria of tear breakup time, tear meniscus level, presence of mucoid secretions, Schirmer's test with and without anesthesia, and fluorescein and rose Bengal staining patterns of the cornea and conjunctiva). Cytological evaluation was performed in 23 aniridic eyes by impression cytology to determine limbal stem cell status relative to control normal eyes. MAIN OUTCOME MEASURES: Abnormal tear film production and stability, meibomian gland dysfunction, severity of corneal involvement, and limbal stem cell deficiency. RESULTS: Twenty patients (36 eyes) diagnosed with congenital aniridia were classified into 3 groups according to the severity of corneal involvement: mild (2 eyes), moderate (21 eyes), and advanced (13 eyes) corneal changes. Tear breakup time was reduced by an average of 5 seconds in 90.7% of cases, tear meniscus levels were reduced to <0.5 mm in 88.6% of cases, and stenosed meibomian orifices were found in 77.8% of patients. Dry eyes (94%) correlated with the severity of corneal involvement (P = 0.001). Impression cytology revealed metaplasia in all tested cases. Furthermore, 8 of 23 eyes (35%) and 15 of 23 eyes (65%) had early and advanced limbal stem cell deficiency, respectively. CONCLUSIONS: Abnormal tear film stability and meibomian gland dysfunction are newly identified factors in patients with aniridia. Both correlate to the severity of ocular surface disease. Impression cytology is informative in diagnosing various degrees of limbal stem cell deficiency, which is present in all tested aniridia eyes.

Adolescent↗
PubMed1998

Polymerase chain reaction-based risk assessment for Wilms tumor in sporadic aniridia.

PURPOSE: Sporadic cases of aniridia have a 30% risk for the development of Wilms tumor. Current guidelines for sporadic aniridia recommend screening by renal ultrasonography for the presence of tumors every 6 months until age 5 years. Deletions of chromosome 11p13 that affect both PAX6 (aniridia) and WT1 (Wilms tumor) loci are the basis for the association of these two uncommon disorders. We sought to develop a rapid polymerase chain reaction-based test that could rule out a chromosome 11p13 deletion covering the PAX6-WT1 region in sporadic aniridia. METHODS: Five patients with sporadic aniridia were recruited. Polymerase chain reaction-based genotyping was carried out for six highly informative marker loci across the PAX6-WT1 region to determine whether these patients had one or two haplotypes. The results were compared with those obtained from two cell lines with known deletions in the PAX6-WT1 region. RESULTS: All five patients were heterozygous at least at one of the four marker loci in the PAX6-WT1 region, indicating that there were no cases of gross chromosomal deletion. The cell lines showed hemizygosity in the four marker loci within the PAX6-WT1 region and in one of the two flanking marker loci. CONCLUSIONS: We have developed a rapid DNA test with an estimated sensitivity of 94.0% to 99.2%, using standard DNA diagnostic techniques and equipment, to rule out chromosomal deletion in sporadic aniridia. Patients in whom a chromosome 11p13 deletion has been ruled out do not require repeated renal imaging to screen for Wilms tumor.

Aniridia↗
PubMed2004

PAX6 gene variations associated with aniridia in south India.

BACKGROUND: Mutations in the transcription factor gene PAX6 have been shown to be the cause of the aniridia phenotype. The purpose of this study was to analyze patients with aniridia to uncover PAX6 gene mutations in south Indian population. METHODS: Total genomic DNA was isolated from peripheral blood of twenty-eight members of six clinically diagnosed aniridia families and 60 normal healthy controls. The coding exons of the human PAX6 gene were amplified by PCR and allele specific variations were detected by single strand conformation polymorphism (SSCP) followed by automated sequencing. RESULTS: The sequencing results revealed novel PAX6 mutations in three patients with sporadic aniridia: c.715ins5, [c.1201delA; c.1239A>G] and c.901delA. Two previously reported nonsense mutations were also found: c.482C>A, c.830G>A. A neutral polymorphism was detected (IVS9-12C>T) at the boundary of intron 9 and exon 10. The two nonsense mutations found in the coding region of human PAX6 gene are reported for the first time in the south Indian population. CONCLUSION: The genetic analysis confirms that haploinsuffiency of the PAX6 gene causes the classic aniridia phenotype. Most of the point mutations detected in our study results in stop codons. Here we add three novel PAX6 gene mutations in south Indian population to the existing spectrum of mutations, which is not a well-studied ethnic group. Our study supports the hypothesis that a mutation in the PAX6 gene correlates with expression of aniridia.

Adolescent↗
PubMed2000

[Implantation of black diaphragm intraocular lenses in congenital and traumatic aniridia].

PURPOSE: To evaluate the safety and efficacy of the black diaphragm intraocular lens (IOL) implantation for the treatment of congenital and traumatic aniridia. MATERIAL AND METHODS: Seven black diaphragmatic IOLs were implanted in the eyes of 6 patients between 1997 and 1998. There were 5 males and 1 female. The mean age of them was 42.8 years (range: 22-54 years). Follow-up ranged from 9 to 20 months (mean: 14.2 months). Traumatic aniridia was present in 4 eyes and congenital aniridia in 3 eyes. Pars plana vitrectomy was combined with the simple outside-in method of scleral fixation of IOLs in 6 cases. Three of these eyes were aphakic (all with traumatic aniridia) and in 3 eyes (two congenital cases, one traumatic case) subluxated lens was simultaneously removed. In one case of congenital aniridia with mature cataract, ECCE and ciliary sulcus implantation without scleral fixation were performed. RESULTS: There were very few complications. Ciliary sulcus bleeding appeared in 2 cases during scleral fixation. Transient post-operative corneal oedema was observed in 2 eyes, raised intraocular pressure in 3 eyes, and dispersed blood in vitreous cavity in 2 eyes. All IOLs were well centred. The improvement in best corrected visual acuity was achieved in 5 cases, while good pre-operative best corrected visual acuity was maintained in 2 cases. CONCLUSIONS: Diaphragmatic IOL can be fixated to the sclera in cases without capsular support or it can be implanted into ciliary sulcus after ECCE. Reconstruction of 5 mm pupil and intraocular correction of aphakia enable good visual rehabilitation of patients. The combined procedure of pars plana vitrectomy and scleral fixation of diaphragmatic lens is safe and effective in traumatic and congenital aniridia.

Adult↗
PubMed2002

[Aniridia].

Aniridia is a congenital developmental anomaly of the eye that usually affects both eyes. The development of the iris, cornea, lens, angle, optic nerve and retina is disturbed. Aniridia is most often a hereditary disease with an autosomal dominant, rarely autosomal recessive inheritance, but sporadic cases are also possible. The vision function in aniridia has been observed to have a wide range from blindness to a normal visual acuity. The more serious cases where blindness occurs has been due not specifically to the aniridia but to associated conditions like cataract, glaucoma, foveal hypoplasia, corneal dystrophy, nystagmus. Aniridia could be associated with the mental retardation. Some of the sporadic cases develop Wilms' tumor, frequently as part of the WAGR syndrome (Wilms' tumor, aniridia, genitourinary abnormalities and mental retardation).

Adult↗
PubMedDate not supplied

Pars plana vitrectomy and transscleral fixation of black diaphragm intraocular lens for the management of traumatic aniridia.

BACKGROUND AND OBJECTIVES: Partial or complete aniridia occurring after severe ocular trauma is a difficult therapeutic problem. Diaphragm intraocular lenses were developed for the correction of aniridia, but the safety and efficacy of implanting such lenses are not well established in traumatic cases because of very few reports, and the small number of cases studied. PATIENTS AND METHODS: Six patients, 4 men and 2 women with a mean age of 44 years, were treated for traumatic aniridia using pars plana vitrectomy and transscleral fixation of a black diaphragm intraocular lens. Total aniridia was observed in 3 eyes and partial aniridia in 3 eyes. Four eyes were aphakic and severe lens subluxation was seen in 2 eyes. Vitreous hemorrhage coexisted in 2 patients and bacterial endophthalmitis was present in 1 patient. Follow-up time ranged between 4 and 39 months (mean, 23 months). RESULTS: Best-corrected visual acuity improved in 5 patients and 1 remained unchanged. Good visual acuity (20/20 - 20/40) was achieved in all cases and all lenses were well-centered. No severe complications were noted. Three of 6 patients required glaucoma topical medications pre- and postoperatively achieving good intraocular pressure control. CONCLUSION: The management of traumatic aniridia using pars plana vitrectomy and implantation of scleral fixation black diaphragm intraocular lenses seem to be safe. Very good functional results and lack of severe complications are encouraging. Additional cases with a longer follow-up study are necessary to support our opinion.

Adult↗
PubMed1998

Missense mutations in the PAX6 gene in aniridia.

PURPOSE: Aniridia is caused by a mutation of the PAX6 gene. Haploinsufficiency of the gene product is thought to result in the aniridia phenotype, because most mutations thus far detected have been large deletions encompassing the entire gene and nonsense, frameshift, or splice errors that result in premature translational termination on one of the alleles. Only two missense mutations have been detected in aniridia pedigrees, each of which occurs in its paired domain or homeodomain. In this study, four novel missense mutations were found in three aniridia pedigrees. METHODS: Polymerase chain reaction-single-strand conformation polymorphism analysis and sequencing of the PAX6 gene were performed using genomic DNA of three aniridia pedigrees and more than 100 healthy control subjects. RESULTS: Three mutations occurred in the N-terminal subdomain of the paired domain, namely N17S, I29V, and R44Q, the first two of which were detected on the same allele of one patient. The other mutation (Q178H) was in the linking portion of the paired domain and homeodomain. CONCLUSIONS: These missense mutations give rise to haploinsufficiency by another route, because the missense mutations presented here resulted in an aniridia phenotype indistinguishable from that caused by a heterozygous deletion of the entire PAX6 gene.

Adult↗
PubMed1975

Wilms' tumor in seven children with congenital aniridia.

This report reviews our experience with 26 infants and children who demonstrate the syndrome of congenital aniridia. Twenty patients exhibited congenital sporadic aniridia, and unilateral Wilms' tumor has developed in seven of them. Six of the total of 26 patients had familial aniridia and none has shown evidence of the development of a Wilms' tumor or any other malignant tumor to date. Fraumeni studied 15 patients with congenital sporadic aniridia. Five developed Wilms' tumors. In the combined series of 35 patients with congenital sporadic aniridia, 12 patients have developed Wilms' tumor for an incidence of 34%. A brief review of our experience and a suggested protocol for the evaluation of patients with congenital aniridia is presented.

Abnormalities, Multiple↗
PubMed2026

Small Copy Number Neutral Intrachromosomal Translocation of PAX6 and Aniridia.

IMPORTANCE: Approximately 5% to 10% of individuals with classic aniridia do not receive a molecular diagnosis after clinical testing for variants in PAX6 and its downstream regulatory region. OBJECTIVE: To apply optical genome mapping (OGM) and long-read whole-genome sequencing (lrWGS) to diagnose an individual with unexplained classic aniridia. DESIGN, SETTING, AND PARTICIPANTS: High-quality DNA was extracted from the blood of a 16-year-old male patient with classic aniridia and prior negative clinical test results that included sequencing and copy number analysis of PAX6 exons and downstream regulatory region as well as genomic analysis via short-read whole-genome sequencing (srWGS) and analyzed using OGM and lrWGS. All analyses were performed in a research laboratory in Wisconsin from January 2019 to September 2025. INTERVENTIONS: OGM and lrWGS. MAIN OUTCOMES AND MEASURES: Identification of a structural variant disrupting PAX6 expression in an individual with classic aniridia, following negative prior testing including srWGS. RESULTS: OGM identified a 55-kb deletion on 11p13 encompassing all PAX6 exons and exon 12 of ELP4, with insertion of this segment into 11q21. lrWGS delineated the exact breakpoints, confirming that the downstream regulatory region, required for normal PAX6 expression, remained at the 11p13 locus. Consequently, the translocated copy of PAX6 at 11q21 is expected to lack expression due to the loss of its essential regulatory elements. CONCLUSIONS AND RELEVANCE: These findings in an individual with classic aniridia harboring an intrachromosomal rearrangement at the PAX6 locus identified by OGM and lrWGS may represent the smallest reported structural variant to separate the PAX6 coding sequence from its downstream regulatory region. This structural variant may have fallen below the detection threshold of srWGS due to its balanced nature and small size, suggesting OGM and lrWGS would be needed for definitive identification.

Aniridia↗
PubMed2000

Mutation in the PAX6 gene in twenty patients with aniridia.

This is a report on the nature of the mutations in the PAX6 gene in twenty patients with aniridia. Five of the twenty patients had sporadic aniridia with deletions in chromosome 11p13. Three of the five had WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, mental retardation), and the other two had deletions whose breakpoints occurred between the PAX6 and the WT1 genes. Allelic losses at PAX6 were of paternal origin. The remaining fifteen patients with aniridia had intragenic mutations in the PAX6 gene, with mutations found from exon 5 to exon 12. Twelve cases of dysfunctional PAX6 were due to premature termination of the protein by nonsense mutations (five cases), splicing defect (one case), deletion (two cases), deletion-insertions (two cases), and tandem repeat insertions (two cases). One patient (P2) had a PAX6 protein with de novo in-frame deletion of alanine, arginine, and proline at codon positions 37, 38, and 39. These codons are in the paired box region, and codon 38 is in contact with the phosphate group of the sugar-phosphate backbone of the target DNA. Another patient (P8) had a single nucleotide transition at c.1182 (nucleotide number, Genbank accession #M93650, used as in Glaser et al. [1992]), which generated both a missense mutation (Q255H) and a splicing defect. A missense mutation was found at G387E in a third patient (P10). All observed mutations support the notion that haploinsufficiency in PAX6 results in aniridia and associated eye anomalies.

Aniridia↗
PubMed2003

Aniridia and Wilm's tumor.

Aniridia (absence of iris) is a congenital, bilateral, uncommon panocular disorder. Whereas the occurrence of aniridia in the general population is 1:50000, it is present in about 1 in 70 patients with Wilm's tumor. This aniridia is sporadic and Wilm's tumor in these cases presents at an unusually early age. Aniridia was present in two cases out of 60 cases of Wilm's tumor operated at PGIMS, Rohtak. Both cases presented below two years of age. The recognition of a child with sporadic aniridia should alert to the increased risk of development of Wilm's tumor.

Aniridia↗
PubMed2004

[Bilateral congenital aniridia: 5 case reports].

INTRODUCTION: Aniridia is a rare familial or sporadic disorder affecting not only the iris but also the cornea, angle structures, lens, optic nerve, and fovea. This disorder may be associated with many other systemic abnormalities such as urogenital malignancies. CASE REPORTS: A 44-Year-old man who complained of visual loss presented bilateral congenital aniridia with corneal dystrophy and dense cataract. His 12-Year-old daughter also presented visual loss with severe bilateral corneal dystrophy and total congenital cataract associated with aniridia. Two other daughters, 18 and 23 Years of age, and an 11-Year-old son had nystagmus with bilateral congenital cataract and ectopia lentis. Clinical and radiological investigations did not disclose evidence of extraocular abnormalities in this family. Three patients underwent cataract extraction without intraocular implantation and the aphakia was corrected with glasses. All three patients progressed well. DISCUSSION: This family provided a good illustration of the different clinical spectra of ocular involvement in congenital aniridia and its management difficulties, above all those of cataract surgery and correction of aphakia. CONCLUSION: Aniridia is a genetic disease with possible association with other ocular and systemic disorders, which may compromise visual and vital prognosis. Genetic advice is very important in such families.

Adult↗
PubMed2005

Use of the artificial iris implant in patients with aniridia.

BACKGROUND: Aniridia (or partial aniridia) often occurs as a result of a penetrating ocular trauma. This condition may cause symptoms including glare, light sensitivity, reduced vision, and asymmetric appearance. Options for these patients include specialty contact lenses, corneal tattooing, and artificial iris implants. This article details six patients who experienced penetrating trauma with significant iris tissue loss and who chose to have an artificial iris implant. CASE REPORTS: Six patients with traumatic aniridia were enrolled in a single-site, single-surgeon study. They were followed for one year postoperatively. All six were complex cases that had multiple eye problems, such as aphakia, corneal scarring, corneal graft rejection, and retinal detachment. All participants were male. All patients experienced decrease in glare and light sensitivity following artificial iris implant surgery. Two experienced improved best-corrected vision (BCVA). All six patients felt the cosmetic appearance of their affected eye improved. CONCLUSIONS: The artificial iris device provides an effective means of treating traumatic aniridia. Optometrists often work with patients who have experienced a penetrating ocular trauma, with complete or partial aniridia as a complication. In cases in which nonsurgical means are not effective in returning the patient to comfort and productivity, an artificial iris implant should be considered.

Adult↗
PubMed1992

Genomic structure, evolutionary conservation and aniridia mutations in the human PAX6 gene.

Aniridia is a semidominant disorder in which development of the iris, lens, cornea and retina is disturbed. The mouse mutation Small eye (Sey), which has been proposed as a model for aniridia, results from defects in Pax-6, a gene containing paired-box and homeobox motifs that is specifically expressed in the developing eye and brain. To test the role of PAX6 in aniridia, we isolated human cDNA clones and determined the intron-exon structure of this gene. PAX6 spans 22 kilobases and is divided into 14 exons. Analysis of DNA from 10 unrelated aniridia patients revealed intragenic mutations in three familial and one sporadic case. These findings indicate that the human aniridia and murine Small eye phenotypes arise from homologous defects in PAX6.

Amino Acid Sequence↗
PubMed2005

A case of novel de novo paired box gene 6 (PAX6) mutation with early-onset diabetes mellitus and aniridia.

BACKGROUND: Paired box gene 6 (PAX6) is a transcription factor involved in eye development. Mutations of PAX6 cause congenital eye anomalies, such as aniridia. PAX6 is also involved in the development of the endocrine pancreas, and reported to be a genetic factor common to aniridia and glucose intolerance, although the latter is usually mild. Here, we describe a case of PAX6 mutation with early-onset diabetes mellitus. CASE REPORT: A 27-year-old woman was referred to our clinic. She was diagnosed having diabetes at the age of 15 with negative glutamic acid decarboxylase (GAD) antibody. Insulin treatment was started at age 24. Because she had aniridia, PAX6 gene mutation was investigated and a heterozygous 2-bp deletion (c.402del2) was identified. Her parents did not have aniridia and PAX6 mutations. Heterozygous PAX6 mutation may cause glucose intolerance. However, cases of early-onset diabetes mellitus have not been reported. Her parents did not have diabetes, but their insulinogenic indices were low (0.25 and 0.3, respectively). We thought her early-onset diabetes was partly as a result of PAX6 mutation and partly because of an unknown insulin secretory defect inherited from her parents. We could not find any mutations in HNF-1alpha, -1beta, -4alpha, IPF-1, ISL-1, BEAT2/NeuroD1, PAX4, and amylin genes. CONCLUSIONS: We report a case of PAX6 gene mutation with early-onset diabetes mellitus and aniridia. Low insulin secretory capacity in her parents suggested that her insulin secretory defect is as a result of not only PAX6 mutation but other genetic factors inherited from her parents.

Adult↗