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Genes Sep 2021Treacher Collins syndrome (TCS) is associated with abnormal differentiation of the first and second pharyngeal arches, occurring during fetal development. Features of... (Review)
Review
Treacher Collins syndrome (TCS) is associated with abnormal differentiation of the first and second pharyngeal arches, occurring during fetal development. Features of TCS include microtia with conductive hearing loss, slanting palpebral fissures with possibly coloboma of the lateral part of lower eyelids, midface hypoplasia, micrognathia as well as sporadically cleft palate and choanal atresia or stenosis. TCS occurs in the general population at a frequency of 1 in 50,000 live births. Four subtypes of Treacher Collins syndrome exist. TCS can be caused by pathogenic variants in the , , and genes. Genetically, the gene contains 27 exons which encodes the Treacle protein. In , over 200 pathogenic variants have been identified, of which most are deletions leading to a frame-shift, that result in the formation of a termination codon. In the presented article, we review the genetics and phenotype of TCS as well as the management and surgical procedures utilized for treatment.
Topics: Choanal Atresia; DNA-Directed RNA Polymerases; Humans; Mandibulofacial Dysostosis; Nuclear Proteins; Phosphoproteins; Syndrome
PubMed: 34573374
DOI: 10.3390/genes12091392 -
Eye (London, England) Aug 2021Typical ocular coloboma is caused by defective closure of the embryonal fissure. The occurrence of coloboma can be sporadic, hereditary (known or unknown gene defects)... (Review)
Review
Typical ocular coloboma is caused by defective closure of the embryonal fissure. The occurrence of coloboma can be sporadic, hereditary (known or unknown gene defects) or associated with chromosomal abnormalities. Ocular colobomata are more often associated with systemic abnormalities when caused by chromosomal abnormalities. The ocular manifestations vary widely. At one extreme, the eye is hardly recognisable and non-functional-having been compressed by an orbital cyst, while at the other, one finds minimalistic involvement that hardly affects the structure and function of the eye. In the fundus, the variability involves the size of the coloboma (anteroposterior and transverse extent) and the involvement of the optic disc and fovea. The visual acuity is affected when coloboma involves disc and fovea, or is complicated by occurrence of retinal detachment, choroidal neovascular membrane, cataract, amblyopia due to uncorrected refractive errors, etc. While the basic birth anomaly cannot be corrected, most of the complications listed above are correctable to a great extent. Current day surgical management of coloboma-related retinal detachments has evolved to yield consistently good results. Cataract surgery in these eyes can pose a challenge due to a combination of microphthalmos and relatively hard lenses, resulting in increased risk of intra-operative complications. Prophylactic laser retinopexy to the border of choroidal coloboma appears to be an attractive option for reducing risk of coloboma-related retinal detachment. However, a majority of the eyes have the optic disc within the choroidal coloboma, thus making it difficult to safely administer a complete treatment.
Topics: Coloboma; Humans; Microphthalmos; Optic Disk; Retinal Detachment; Visual Acuity
PubMed: 33746210
DOI: 10.1038/s41433-021-01501-5 -
Orphanet Journal of Rare Diseases Sep 2006CHARGE syndrome was initially defined as a non-random association of anomalies (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital... (Review)
Review
CHARGE syndrome was initially defined as a non-random association of anomalies (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, Ear anomalies/deafness). In 1998, an expert group defined the major (the classical 4C's: Choanal atresia, Coloboma, Characteristic ears and Cranial nerve anomalies) and minor criteria of CHARGE syndrome. Individuals with all four major characteristics or three major and three minor characteristics are highly likely to have CHARGE syndrome. However, there have been individuals genetically identified with CHARGE syndrome without the classical choanal atresia and coloboma. The reported incidence of CHARGE syndrome ranges from 0.1-1.2/10,000 and depends on professional recognition. Coloboma mainly affects the retina. Major and minor congenital heart defects (the commonest cyanotic heart defect is tetralogy of Fallot) occur in 75-80% of patients. Choanal atresia may be membranous or bony; bilateral or unilateral. Mental retardation is variable with intelligence quotients (IQ) ranging from normal to profound retardation. Under-development of the external genitalia is a common finding in males but it is less apparent in females. Ear abnormalities include a classical finding of unusually shaped ears and hearing loss (conductive and/or nerve deafness that ranges from mild to severe deafness). Multiple cranial nerve dysfunctions are common. A behavioral phenotype for CHARGE syndrome is emerging. Mutations in the CHD7 gene (member of the chromodomain helicase DNA protein family) are detected in over 75% of patients with CHARGE syndrome. Children with CHARGE syndrome require intensive medical management as well as numerous surgical interventions. They also need multidisciplinary follow up. Some of the hidden issues of CHARGE syndrome are often forgotten, one being the feeding adaptation of these children, which needs an early aggressive approach from a feeding team. As the child develops, challenging behaviors become more common and require adaptation of educational and therapeutic services, including behavioral and pharmacological interventions.
Topics: Abnormalities, Multiple; Choanal Atresia; Coloboma; DNA Helicases; DNA-Binding Proteins; Face; Genitalia; Heart Defects, Congenital; Humans; Mutation; Syndrome
PubMed: 16959034
DOI: 10.1186/1750-1172-1-34 -
Orphanet Journal of Rare Diseases Mar 2006The otodental syndrome also named otodental dysplasia, is characterised by a striking dental phenotype known as globodontia, associated with sensorineural high frequency... (Review)
Review
The otodental syndrome also named otodental dysplasia, is characterised by a striking dental phenotype known as globodontia, associated with sensorineural high frequency hearing loss and eye coloboma. Globodontia occurs in both primary and permanent dentition, affecting canine and molar teeth (i.e. enlarged bulbous malformed posterior teeth with almost no discernable cusps or grooves). The condition appears to be inherited in an autosomal dominant mode, although sporadic cases have been reported. It is a rare disease, a few families have been described in the literature. In the British family, the locus for oculo-oto-dental syndrome was mapped to 20q13.1 within a 12-cM critical chromosomal region. Dental management is complex, interdisciplinary and will include regular follow up, scheduled teeth extraction and orthodontic treatment. Hearing checks and, if necessary, hearing aids are mandatory, as well as eye examination and ad hoc treatment if necessary.
Topics: Abnormalities, Multiple; Adult; Child; Coloboma; Cuspid; Dental Enamel Hypoplasia; Diagnosis, Differential; Face; Hearing Loss, Sensorineural; Humans; Malocclusion; Molar; Odontoma; Syndrome; Tooth Abnormalities
PubMed: 16722606
DOI: 10.1186/1750-1172-1-5 -
Indian Journal of Ophthalmology Jun 2023Scleral fistulas are known to develop following blunt trauma in patients with retinochoroidal coloboma. These cases can be managed by surgical options such as silicone...
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.
Topics: Humans; Retinal Detachment; Coloboma; Visual Acuity; Choroid; Retinal Diseases; Macular Degeneration; Vitrectomy
PubMed: 37322728
DOI: 10.4103/IJO.IJO_250_23 -
Child's Nervous System : ChNS :... Nov 2020Pai syndrome is a rare idiopathic developmental condition characterized by midline craniofacial abnormalities. It was originally described as the presence of a median... (Review)
Review
BACKGROUND
Pai syndrome is a rare idiopathic developmental condition characterized by midline craniofacial abnormalities. It was originally described as the presence of a median cleft lip, cutaneous polyps of the nasal mucosa and face, and midline lipomas of the central nervous system, mostly at the corpus callosum. However, there is great phenotypical variability and these characteristics are rarely all present at once.
OBJECTIVE
The aim of this review was to analyze the available evidence regarding Pai syndrome in order to better delineate this rare condition and its features.
METHODS
We analyzed the PubMed database using the words "Pai syndrome", "frontonasal dysplasia", "cleft lip", "nasal polyp", "facial polyp", and "corpus callosum lipoma", including reviews, case reports and case series.
CONCLUSION
There is no consensus regarding the diagnostic criteria of Pai syndrome up to date. It is usually diagnosed at birth, and its incidence is often underestimated. At present, the etiology of Pai syndrome is unknown. Several hypotheses regarding its genetic background have been made; however, there are not enough data yet to elucidate this point. An improved awareness could help in diagnosing the condition and performing the necessary investigations. These patients should have a multidisciplinary follow-up.
Topics: Agenesis of Corpus Callosum; Cleft Lip; Coloboma; Humans; Infant, Newborn; Lipoma; Nasal Polyps; Skin Diseases
PubMed: 32651596
DOI: 10.1007/s00381-020-04788-z -
Experimental Eye Research Apr 2020Optic fissure closure defects result in uveal coloboma, a potentially blinding condition affecting between 0.5 and 2.6 per 10,000 births that may cause up to 10% of... (Review)
Review
Optic fissure closure defects result in uveal coloboma, a potentially blinding condition affecting between 0.5 and 2.6 per 10,000 births that may cause up to 10% of childhood blindness. Uveal coloboma is on a phenotypic continuum with microphthalmia (small eye) and anophthalmia (primordial/no ocular tissue), the so-called MAC spectrum. This review gives a brief overview of the developmental biology behind coloboma and its clinical presentation/spectrum. Special attention will be given to two prominent, syndromic forms of coloboma, namely, CHARGE (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, and Ear anomalies/deafness) and COACH (Cerebellar vermis hypoplasia, Oligophrenia, Ataxia, Coloboma, and Hepatic fibrosis) syndromes. Approaches employed to identify genes involved in optic fissure closure in animal models and recent advances in live imaging of zebrafish eye development are also discussed.
Topics: Abnormalities, Multiple; Animals; Ataxia; Brain; Cholestasis; Coloboma; Genetic Predisposition to Disease; Humans; Liver Diseases; Uvea
PubMed: 32032630
DOI: 10.1016/j.exer.2020.107940 -
Indian Journal of Ophthalmology Jul 2022
Topics: Coloboma; Humans; Iris; Retinal Diseases
PubMed: 35791195
DOI: 10.4103/ijo.IJO_164_22 -
Journal of Medical Genetics Aug 1993A new classification of microphthalmos and coloboma is proposed to bring order to the complexity of clinical and aetiological heterogeneity of these conditions. A... (Review)
Review
A new classification of microphthalmos and coloboma is proposed to bring order to the complexity of clinical and aetiological heterogeneity of these conditions. A phenotypic classification is presented which may help the clinician to give a systematic description of the anomalies. The phenotype does not predict the aetiology but a systematic description of ocular and systemic anomalies improves syndrome identification. There are two major classes, total and partial microphthalmos, and a subclassification which follows the embryology of the anomalies. The aetiological classification consists of three classes: (1) genetic (monogenic and chromosomal), (2) prenatally acquired (teratological agents and intrauterine deformations), and (3) associations. Genetic disorders give rise to malformations; prenatally acquired anomalies are disruptions or deformations. The aetiological classification can be applied to other congenital birth defects and improves counselling of families. Recurrence risks vary considerably between the classes.
Topics: Coloboma; Humans; Microphthalmos; Phenotype
PubMed: 8411053
DOI: 10.1136/jmg.30.8.664 -
European Journal of Human Genetics :... Dec 2011Renal coloboma syndrome (RCS), also called papillorenal syndrome, is an autosomal dominant condition characterized by optic nerve dysplasia and renal hypodysplasia. The... (Review)
Review
Renal coloboma syndrome (RCS), also called papillorenal syndrome, is an autosomal dominant condition characterized by optic nerve dysplasia and renal hypodysplasia. The eye anomalies consist of a wide and sometimes excavated dysplastic optic disc with the emergence of the retinal vessels from the periphery of the disc, frequently called optic nerve coloboma or morning glory anomaly. Associated findings may include a small corneal diameter, retinal coloboma, scleral staphyloma, optic nerve cyst and pigmentary macular dysplasia. The kidney abnormalities consist of small and abnormally formed kidneys known as renal hypodysplasia. Histologically, kidneys exhibit fewer than the normal number of glomeruli and these glomeruli are enlarged, a finding called oligomeganephronia. Consequences of the ocular malformations include decreased visual acuity and retinal detachment. Consequences of the renal hypodysplasia include hypertension, proteinuria and renal insufficiency that frequently progresses to end-stage kidney disease. High frequency hearing loss has been reported. Autosomal dominant mutations in PAX2 can be identified in nearly half of all patients with clinical findings suggestive of RCS, however, the majority of published cases have mutations in PAX2, thus biasing the known information about the phenotype.
Topics: Animals; Coloboma; Disease Models, Animal; Genetic Counseling; Genetic Testing; Humans; Mutation; PAX2 Transcription Factor; Renal Insufficiency; Vesico-Ureteral Reflux
PubMed: 21654726
DOI: 10.1038/ejhg.2011.102