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618 result(s) for "Coloboma"
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Clinical spectrum, genetics and management insights of PAX2-related disorder in nine children
Background Renal coloboma syndrome (RCS) is a rare autosomal dominant genetic disorder associated with the paired box gene 2 ( PAX2) . Over the past three decades, PAX2 variants have manifested with vast phenotype and genotype heterogeneity, with limited experience gained regarding its clinical progression and management strategies. Methods We included nine Chinese children diagnosed with PAX2 -related disorder at Beijing Children's Hospital. The medical records were retrospectively reviewed, and the demographic data, clinical manifestations, genetic testing results, imaging examination findings, laboratory tests, and renal biopsy results were recorded and analyzed. Results Eight distinct PAX2 pathogenic variants, including four novel variants, were identified in nine children. All patients exhibited developmental abnormalities of the urinary system, while two presented with ocular abnormalities with retinal myelinated nerve fibers identified as a novel manifestation of PAX2 -related disorder. Cranial imaging examinations were performed on three patients, revealing vascular anatomical abnormalities. Five patients received empirical treatment with angiotensin-converting enzyme inhibitors (ACEIs), resulting in varied therapeutic outcomes. Conclusion PAX2 variants exhibit significant clinical diversity, and our findings further expand the genotype–phenotype spectrum of PAX2 -related disorder. The variable efficacy of ACEIs highlights the importance of personalized evaluation and treatment strategies and extended follow-up periods in the future.
The deceptive coloboma
Background: Scleral fistulas are known to develop following blunt trauma in patients with retinochoroidal coloboma. These cases can be managed by surgical options such as silicone buckles, or with glue and scleral patch graft. Some cases have been shown to close spontaneously. We report the first-ever case managed by vitrectomy, endophotocoagulation, and gas tamponade. Purpose: We present a rare and interesting case of an atypical choroidal coloboma with traumatic scleral fistula due to blunt trauma manifesting with hypotony-related disc edema, maculopathy, and chorioretinal folds, which was managed surgically with vitrectomy, endophotocoagulation, and gas tamponade with a good anatomical and visual outcome. Synopsis: The video contains the case description and surgical management of a traumatic scleral fistula in a patient with atypical superotemporal choroidal coloboma. The patient developed hypotonic maculopathy and disc edema after 3 months following a blunt trauma sustained in a road traffic accident. A scleral fistula was suspected at the temporal edge of the coloboma but could not be accurately localized. In addition, due to the edge effect of the coloboma, the external repair was difficult. Hence, vitrectomy with internal tamponade was attempted. Highlights: The video highlights a different surgical approach to managing a traumatic scleral fistula at the edge of a retinochoroidal coloboma. There was a risk of leakage of intravitreal fluid into the orbit through the fistula; however, the gas bubble gave a better tamponade due to higher surface tension. It sealed the fistula presumably by creating a trap-door-like effect. The endophotocoagulation helped create adhesion between the tissues at the edge of the coloboma effectively sealing it. This was followed by a rapid recovery of the hypotony-related problems with good vision. Traumatic scleral fistula, at a difficult place such as the edge of a coloboma, can be successfully closed from an internal approach with vitrectomy, endolaser, and gas tamponade. Video link: https://youtu.be/6rxgtFyy6cw Key words: Gas tamponade, retinochoroidal coloboma, scleral fistula, traumatic scleral rupture, vitrectomy
Management of anophthalmia, microphthalmia and coloboma in the newborn, shared care between neonatologist and ophthalmologist: a literature review
Congenital ocular anomalies significantly contribute to global disability, with 15–20% of infant blindness attributed to these anomalies. This study examined anophthalmia, microphthalmia, and coloboma (AMC) through collaborative neonatology and ophthalmology care. The global prevalence of AMC varies: anophthalmia at 0.6–4.2 per 100,000 births and microphthalmia at 2–17 per 100,000 births, with a combined prevalence of up to 30 per 100,000. The prevalence of coloboma, alone or associate with other eye defects is 2–19 per 100,000 live births. Anophthalmia and microphthalmia may present as isolated or genetic syndromes, necessitating comprehensive evaluation. AMC etiology encompasses genetic and environmental factors. Chromosomal aberrations and mutations in genes such as PAX6 , SOX2 , OTX2 , and CHD7 are contributors. Syndromic associations, such as CHARGE (heart defect, atresia choanae, retarded growth and development, genital hypoplasia, ear anomalies/deafness) syndrome, underscore the complexity of this syndrome. Early AMC diagnosis is pivotal for timely intervention. This work provides a literature review offering insights for effective management and genetic counseling in a pediatric context.
MiR-204 is responsible for inherited retinal dystrophy associated with ocular coloboma
Ocular developmental disorders, including the group classified as microphthalmia, anophthalmia, and coloboma (MAC) and inherited retinal dystrophies, collectively represent leading causes of hereditary blindness. Characterized by extreme genetic and clinical heterogeneity, the separate groups share many common genetic causes, in particular relating to pathways controlling retinal and retinal pigment epithelial maintenance. To understand these shared pathways and delineate the overlap between these groups, we investigated the genetic cause of an autosomal dominantly inherited condition of retinal dystrophy and bilateral coloboma, present in varying degrees in a large, five-generation family. By linkage analysis and exome sequencing, we identified a previously undescribed heterozygous mutation, n.37C > T, in the seed region of microRNA-204 (miR-204), which segregates with the disease in all affected individuals. We demonstrated that this mutation determines significant alterations of miR-204 targeting capabilities via in vitro assays, including transcriptome analysis. In vivo injection, in medaka fish ( Oryzias latipes ), of the mutated miR-204 caused a phenotype consistent with that observed in the family, including photoreceptor alterations with reduced numbers of both cones and rods as a result of increased apoptosis, thereby confirming the pathogenic effect of the n.37C > T mutation. Finally, knockdown assays in medaka fish demonstrated that miR-204 is necessary for normal photoreceptor function. Overall, these data highlight the importance of miR-204 in the regulation of ocular development and maintenance and provide the first evidence, to our knowledge, of its contribution to eye disease, likely through a gain-of-function mechanism. Significance MicroRNAs are key players in the regulation of gene expression. An understanding of human conditions caused by microRNA mutations provides insight into mechanisms of gene regulation and into the interplay between development and maintenance in tissue homeostasis. The eye represents a notable target tissue of genetic diseases. Inherited retinal degenerations and developmental eye disorders are two separate groups that represent leading causes of blindness worldwide. Identifying underlying genetic causes of such conditions is important for diagnosis, counseling, and potential therapy development. We identified a dominant mutation in microRNA-204 as the genetic cause of a unique phenotype of retinal degeneration and coloboma and thus highlight the importance of microRNA-204 as a master regulator of ocular development and normal maintenance.
frizzled 5 mutant zebrafish are genetically sensitised to developing microphthalmia and coloboma
Microphthalmia and coloboma are structural malformations of the eyes that arise from defective morphogenesis and are among the most severe defects associated with paediatric blindness. Frizzled class receptor 5 (FZD5) is a Wnt receptor expressed in the developing eye, and individuals with variants in FZD5 exhibit microphthalmia/coloboma, supporting a role for this receptor in human eye formation. Here, we show that zebrafish fzd5 mutants homozygous for complete loss-of-function or predicted dominant-negative alleles display no obvious eye defects during embryogenesis. Rather, they develop eye defects comparable to those described in humans only upon simultaneous abrogation of additional genes associated with ocular malformations. Thus, eye development can occur normally in the absence of Fzd5 in zebrafish, but mutants are sensitised to developing eye malformations. By exploiting the sensitised nature of the fzd5 mutants, we further identified angio-associated migratory cell protein (aamp) as a novel gene involved in eye morphogenesis. Overall, our study confirms the importance of considering multiple genetic contributions when searching for the molecular aetiology of ocular malformations in humans.
A case of nevoid basal cell carcinoma syndrome associated with optic nerve coloboma and epiretinal membrane
Purpose To report the first case of nevoid basal cell carcinoma syndrome associated with optic nerve coloboma and epiretinal membrane in Chinese patient. Observations A 12-year-old female presented with bilateral visual decline. Examination revealed a porcelain-white optic nerve coloboma and epiretinal membrane in the right eye. OCT confirmed deepened optic disc excavation and a thin epiretinal membrane. Visual field testing showed an inferonasal arcuate scotoma. Systemic findings included odontogenic keratocyst and cutaneous basal cell carcinomas. Genetic testing identified a heterozygous PTCH1 mutation. Conclusions and importance Optic nerve coloboma and epiretinal membrane, though rare, can be initial signs of nevoid basal cell carcinoma syndrome. Ophthalmologists are critical in identifying these manifestations, enabling early diagnosis and comprehensive management.
Couching of cataractous lens in microphthalmic eyes with irido-fundal coloboma: revisiting the historical technique
Purpose Cataract surgery in microphthalmic eyes is challenging due to anatomical restraints, hard bulky nucleus. This series aims to evaluate the safety and efficacy of couching of intraocular lens in irido-fundal coloboma with microphthalmos. Setting Tertiary care centre in South India. Design Retrospective non-comparative study in eyes with irido-fundal coloboma, corneal diameter < 7 mm and brown cataract. Visual acuity less than 6/60 in other eye. Methods Anterior chamber entry made, zonules broken and lens dislocated into the vitreous cavity in a controlled manner. Baseline Clinico-demographic details, corrected distance visual acuity (CDVA), Intra-ocular pressure (IOP), corneal diameter, axial length, lens status and post-surgery CDVA, IOP and complications recorded and followed up for atleast 6 months. Results Fifteen eyes of 15 subjects were evaluated with a mean age 49.4 ± 10.9 years. At baseline, mean IOP 14.5 ± 3.8 mmHg, mean axial length 19.3 ± 0.5 mm, mean corneal diameter was 6.5 ± 0.34 mm and CDVA 2 logMAR which improved to 1.5 logMAR at 3 months ( p value 0.002). Transient spike in IOP in 33.3% subjects was medically managed with no significant difference in IOP ( p  > 0.05) at baseline (14.5 ± 3.8 mmHg), 3 months post-surgery (16 ± 2.8 mmHg) and 6 months post-surgery (14.9 ± 2.5 mmHg). One patient underwent re-couching. No other major complications were noted. Conclusion Couching of cataractous lens is an effective and safe method in microphthalmic eyes with irido-fundal coloboma as last resort procedure, where no other surgical procedure may work. It provides an ambulatory gain of visual acuity in previously non-ambulatory subjects. Corneal measurements help in determining the subset of patients where couching offers viable option.
National study of microphthalmia, anophthalmia, and coloboma (MAC) in Scotland: investigation of genetic aetiology
We report an epidemiological and genetic study attempting complete ascertainment of subjects with microphthalmia, anophthalmia, and coloboma (MAC) born in Scotland during a 16 year period beginning on 1 January 1981. A total of 198 cases were confirmed giving a minimum live birth prevalence of 19 per 100 000. One hundred and twenty-two MAC cases (61.6%) from 115 different families were clinically examined and detailed pregnancy, medical, and family histories obtained. A simple, rational, and apparently robust classification of the eye phenotype was developed based on the presence or absence of a defect in closure of the optic (choroidal) fissure. A total of 85/122 (69.7%) of cases had optic fissure closure defects (OFCD), 12/122 (9.8%) had non-OFCD, and 25/122 (20.5%) had defects that were unclassifiable owing to the severity of the corneal or anterior chamber abnormality. Segregation analysis assuming single and multiple incomplete ascertainment, respectively, returned a sib recurrence risk of 6% and 10% in the whole group and 8.1% and 13.3% in the OFCD subgroup. Significant recurrence risks were found in both unilateral and bilateral disease. In four families, one parent had an OFCD, two of which were new diagnoses in asymptomatic subjects. All recurrences in first degree relatives occurred in the OFCD group with a single first cousin recurrence seen in the non-OFCD group. A total of 84/122 of the MAC cases were screened for mutations in the coding regions of PAX6, CHX10, and SIX3. No pathogenic mutations were identified in the OFCD cases. A single PAX6 homeodomain missense mutation was identified in a subject with partial aniridia that had been initially misclassified as coloboma.