Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (624 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
Congenital anomaly in which some of the structures of the eye are absent due to incomplete fusion of the fetal intraocular fissure during gestation.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Colobomas; Coloboma, Ocular; Colobomas, Ocular; Ocular Colobomas; Coloboma Of Iris, Choroid, And Retina; Ocular Coloboma; Uveoretinal Coloboma; Coloboma, Uveoretinal.
Where it fits in the MeSH classification
- Broader topics
- Eye Abnormalities; Eye Diseases, Hereditary
- Narrower topics
- CHARGE Syndrome; Mandibulofacial Dysostosis
Research landscape
PubMed indexes 4,711 records tagged with the MeSH heading “Coloboma” (counts retrieved 2026-10-29). 625 of them (13.3%) were published from 2020 onward, and the busiest period so far is through 1999 with 2,318 records.
Reviews account for 410 records (8.7%) and meta-analyses for 3. Randomized controlled trials number 2 (0.0%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 2,318 |
| 2000-2009 | 714 |
| 2010-2019 | 1,054 |
| 2020 onward | 625 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 410 | 8.7% |
| Meta-analyses | 3 | 0.1% |
| Randomized controlled trials | 2 | 0.0% |
Method: PubMed query "Coloboma"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-29.
Reading the evidence in rare and inherited diseases
Rare conditions are difficult to study: few patients means small studies, case reports and registries are common, and randomized trials are the exception. Small samples limit precision and can exaggerate effects, and cases reported in the literature may be the most severe or unusual. Evidence from many small studies is best read together. Check how patients were identified, how many were included and how long they were followed.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
The Roles of RNA Polymerase I and III Subunits Polr1c and Polr1d in Craniofacial Development and in Zebrafish Models of Treacher Collins Syndrome [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Ribosome biogenesis is a global process required for growth and proliferation of all cells, yet perturbation of ribosome biogenesis during human development often leads to tissue-specific defects termed ribosomopathies.
- Closing excerpt
- Furthermore, we have established polr1c and polr1d mutant zebrafish as models of Treacher Collins syndrome together with a unifying mechanism underlying its pathogenesis and possible prevention.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (251 words)
Ribosome biogenesis is a global process required for growth and proliferation of all cells, yet perturbation of ribosome biogenesis during human development often leads to tissue-specific defects termed ribosomopathies. Transcription of the ribosomal RNAs (rRNAs) by RNA polymerases (Pol) I and III, is considered a rate limiting step of ribosome biogenesis and mutations in the genes coding for RNA Pol I and III subunits, POLR1C and POLR1D cause Treacher Collins syndrome, a rare congenital craniofacial disorder. Our understanding of the functions of individual RNA polymerase subunits, however, remains poor. We discovered that polr1c and polr1d are dynamically expressed during zebrafish embryonic development, particularly in craniofacial tissues. Consistent with this pattern of activity, polr1c and polr1d homozygous mutant zebrafish exhibit cartilage hypoplasia and cranioskeletal anomalies characteristic of humans with Treacher Collins syndrome. Mechanistically, we discovered that polr1c and polr1d loss-of-function results in deficient ribosome biogenesis, Tp53-dependent neuroepithelial cell death and a deficiency of migrating neural crest cells, which are the primary progenitors of the craniofacial skeleton. More importantly, we show that genetic inhibition of tp53 can suppress neuroepithelial cell death and ameliorate the skeletal anomalies in polr1c and polr1d mutants, providing a potential avenue to prevent the pathogenesis of Treacher Collins syndrome. Our work therefore has uncovered tissue-specific roles for polr1c and polr1d in rRNA transcription, ribosome biogenesis, and neural crest and craniofacial development during embryogenesis. Furthermore, we have established polr1c and polr1d mutant zebrafish as models of Treacher Collins syndrome together with a unifying mechanism underlying its pathogenesis and possible prevention.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 27448281 · DOI · PMC4957770
Prevention of Treacher Collins syndrome craniofacial anomalies in mouse models via maternal antioxidant supplementation [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Craniofacial anomalies account for approximately one-third of all birth defects and are a significant cause of infant mortality.
- Closing excerpt
- Thus maternal antioxidant dietary supplementation may provide an avenue for protection against the pathogenesis of TCS and similar neurocristopathies.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (149 words)
Craniofacial anomalies account for approximately one-third of all birth defects and are a significant cause of infant mortality. Since the majority of the bones, cartilage and connective tissues that comprise the head and face are derived from a multipotent migratory progenitor cell population called the neural crest, craniofacial disorders are typically attributed to defects in neural crest cell development. Treacher Collins syndrome (TCS) is a disorder of craniofacial development and although TCS arises primarily through autosomal dominant mutations in TCOF1, no clear genotype-phenotype correlation has been documented. Here we show that Tcof1 haploinsufficiency results in oxidative stress-induced DNA damage and neuroepithelial cell death. Consistent with this discovery, maternal treatment with antioxidants minimizes cell death in the neuroepithelium and substantially ameliorates or prevents the pathogenesis of craniofacial anomalies in Tcof1(+/-) mice. Thus maternal antioxidant dietary supplementation may provide an avenue for protection against the pathogenesis of TCS and similar neurocristopathies.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 26792133 · DOI · PMC4735750
Functional Insights into Chromatin Remodelling from Studies on CHARGE Syndrome [3]
Abstract reading summary — source excerpts
- Opening excerpt
- CHARGE syndrome is a rare genetic syndrome characterised by a unique combination of multiple organ anomalies.
- Closing excerpt
- The emerging picture from this work suggests that the mechanisms by which CHD7 fine-tunes gene expression are context specific, consistent with the pleiotropic nature of CHARGE syndrome.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (98 words)
CHARGE syndrome is a rare genetic syndrome characterised by a unique combination of multiple organ anomalies. Dominant loss-of-function mutations in the gene encoding chromodomain helicase DNA binding protein 7 (CHD7), which is an ATP-dependent chromatin remodeller, have been identified as the cause of CHARGE syndrome. Here, we review recent work aimed at understanding the mechanism of CHD7 function in normal and pathological states, highlighting results from biochemical and in vivo studies. The emerging picture from this work suggests that the mechanisms by which CHD7 fine-tunes gene expression are context specific, consistent with the pleiotropic nature of CHARGE syndrome.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 26411921 · DOI · PMC4604214
Long-read DNA and RNA sequencing reveal an intronic retrotransposon insertion in TCOF1 causing Treacher Collins syndrome [4]
Abstract reading summary — source excerpts
- Opening excerpt
- Treacher Collins syndrome (TCS) is a craniofacial genetic disorder caused by loss-of-function variants in TCOF1, POLR1B, POLR1C, or POLR1D.
- Closing excerpt
- This work demonstrates the potential of lrRNA-seq and lrGS, to identify pathogenic variants in unexplained genetic disorders.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (126 words)
Treacher Collins syndrome (TCS) is a craniofacial genetic disorder caused by loss-of-function variants in TCOF1, POLR1B, POLR1C, or POLR1D. Here, we describe two previously undiagnosed paternal half-siblings affected with clinical TCS, and their apparently unaffected father. Diagnostic short-read RNA sequencing) identified aberrant expression of TCOF1 and optical genome mapping detected a large genomic insertion therein. Long-read genome sequencing (lrGS) resolved a deep intronic 3.5 kb SINE-VNTR-Alu (SVA) retrotransposon insertion in intron 17 of TCOF1. Long-read RNA sequencing (lrRNA-seq) demonstrated that the insertion was partially exonized inducing isoform switch to the shorter non-canonical TCOF1 isoform c. SVA insertion was confirmed in both half-siblings, and we detected mosaicism in the father. This work demonstrates the potential of lrRNA-seq and lrGS, to identify pathogenic variants in unexplained genetic disorders.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41017149 · DOI · PMC12816837
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article OCULOAURICULOVERTEBRAL DYSPLASIA [5]
- Research article CHD7 mutations and CHARGE syndrome: the clinical implications of an expanding phenotype [6]
- Research article Mutation update on the CHD7 gene involved in CHARGE syndrome [7]
- Research article The genetic architecture of microphthalmia, anophthalmia and coloboma [8]
- Research article CHARGE syndrome [9]
- Research article Ocular coloboma: a reassessment in the age of molecular neuroscience [10]
References
- Noack Watt KE, Achilleos A, Neben CL, Merrill AE, Trainor PA. The Roles of RNA Polymerase I and III Subunits Polr1c and Polr1d in Craniofacial Development and in Zebrafish Models of Treacher Collins Syndrome. . 2016. PMID 27448281 · DOI · PMC4957770
- Sakai D, Dixon J, Achilleos A, Dixon M, Trainor PA. Prevention of Treacher Collins syndrome craniofacial anomalies in mouse models via maternal antioxidant supplementation. . 2016. PMID 26792133 · DOI · PMC4735750
- Basson MA, van Ravenswaaij-Arts C. Functional Insights into Chromatin Remodelling from Studies on CHARGE Syndrome. . 2015. PMID 26411921 · DOI · PMC4604214
- Ferraro F, Kühn N, Rots D, van der Linde HC, Mohseni B, van Unen L, et al.. Long-read DNA and RNA sequencing reveal an intronic retrotransposon insertion in TCOF1 causing Treacher Collins syndrome. . 2026. PMID 41017149 · DOI · PMC12816837
- GORLIN RJ, JUE KL, JACOBSEN U, GOLDSCHMIDT E. OCULOAURICULOVERTEBRAL DYSPLASIA. J Pediatr. 1963. PMID 14071056 · DOI
- Bergman JE, Janssen N, Hoefsloot LH, Jongmans MC, Hofstra RM, van Ravenswaaij-Arts CM. CHD7 mutations and CHARGE syndrome: the clinical implications of an expanding phenotype. J Med Genet. 2011. PMID 21378379 · DOI
- Janssen N, Bergman JE, Swertz MA, Tranebjaerg L, Lodahl M, Schoots J, et al.. Mutation update on the CHD7 gene involved in CHARGE syndrome. Hum Mutat. 2012. PMID 22461308 · DOI
- Williamson KA, FitzPatrick DR. The genetic architecture of microphthalmia, anophthalmia and coloboma. Eur J Med Genet. 2014. PMID 24859618 · DOI
- Blake KD, Prasad C. CHARGE syndrome. Orphanet J Rare Dis. 2006. PMID 16959034 · DOI · PMC1586184
- Gregory-Evans CY, Williams MJ, Halford S, Gregory-Evans K. Ocular coloboma: a reassessment in the age of molecular neuroscience. J Med Genet. 2004. PMID 15591273 · DOI · PMC1735648
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-29.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.