1
|
Dash S, Lamb MC, Lange JJ, McKinney MC, Tsuchiya D, Guo F, Zhao X, Corbin TJ, Kirkman M, Delventhal K, Moore EL, McKinney S, Shiang R, Trainor PA. rRNA transcription is integral to phase separation and maintenance of nucleolar structure. PLoS Genet 2023; 19:e1010854. [PMID: 37639467 PMCID: PMC10513380 DOI: 10.1371/journal.pgen.1010854] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 09/21/2023] [Accepted: 07/03/2023] [Indexed: 08/31/2023] Open
Abstract
Transcription of ribosomal RNA (rRNA) by RNA Polymerase (Pol) I in the nucleolus is necessary for ribosome biogenesis, which is intimately tied to cell growth and proliferation. Perturbation of ribosome biogenesis results in tissue specific disorders termed ribosomopathies in association with alterations in nucleolar structure. However, how rRNA transcription and ribosome biogenesis regulate nucleolar structure during normal development and in the pathogenesis of disease remains poorly understood. Here we show that homozygous null mutations in Pol I subunits required for rRNA transcription and ribosome biogenesis lead to preimplantation lethality. Moreover, we discovered that Polr1a-/-, Polr1b-/-, Polr1c-/- and Polr1d-/- mutants exhibit defects in the structure of their nucleoli, as evidenced by a decrease in number of nucleolar precursor bodies and a concomitant increase in nucleolar volume, which results in a single condensed nucleolus. Pharmacological inhibition of Pol I in preimplantation and midgestation embryos, as well as in hiPSCs, similarly results in a single condensed nucleolus or fragmented nucleoli. We find that when Pol I function and rRNA transcription is inhibited, the viscosity of the granular compartment of the nucleolus increases, which disrupts its phase separation properties, leading to a single condensed nucleolus. However, if a cell progresses through mitosis, the absence of rRNA transcription prevents reassembly of the nucleolus and manifests as fragmented nucleoli. Taken together, our data suggests that Pol I function and rRNA transcription are required for maintaining nucleolar structure and integrity during development and in the pathogenesis of disease.
Collapse
Affiliation(s)
- Soma Dash
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Maureen C. Lamb
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Jeffrey J. Lange
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Mary C. McKinney
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Dai Tsuchiya
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Fengli Guo
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Xia Zhao
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Timothy J. Corbin
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - MaryEllen Kirkman
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Kym Delventhal
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Emma L. Moore
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Sean McKinney
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Rita Shiang
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Paul A. Trainor
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| |
Collapse
|
2
|
Ulhaq ZS, Nurputra DK, Soraya GV, Kurniawati S, Istifiani LA, Pamungkas SA, Tse WKF. A systematic review on Treacher Collins syndrome: Correlation between molecular genetic findings and clinical severity. Clin Genet 2023; 103:146-155. [PMID: 36203321 DOI: 10.1111/cge.14243] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 01/20/2023]
Abstract
Treacher Collins syndrome (TCS, OMIM: 154500) is a rare congenital craniofacial disorder that is caused by variants in the genes TCOF1, POLR1D, POLR1C, and POLR1B. Studies on the association between phenotypic variability and their relative variants are very limited. This systematic review summarized the 53 literatures from PubMed and Scopus to explore the potential TCS genotype-phenotype correlations with statistical analysis. Studies reporting both complete molecular genetics and clinical data were included. We identified that the molecular anomaly within TCOF1 (88.71%) accounted for most TCS cases. The only true hot spot for TCOF1 was detected in exon 24, with recurrent c.4369_4373delAAGAA variant is identified. While the hot spot for POLR1D, POLR1C, and POLR1B were identified in exons 3, 8, and 15, respectively. Our result suggested that the higher severity level was likely to be observed in Asian patients harboring TCOF1 variants rather than POLR1. Moreover, common 5-bp deletions tended to have a higher severity degree in comparison to any variants within exon 24 of TCOF1. In summary, this report suggested the relationship between genetic and clinical data in TCS. Our findings could be used as a reference for clinical diagnosis and further biological studies.
Collapse
Affiliation(s)
- Zulvikar Syambani Ulhaq
- Laboratory of Developmental Disorders and Toxicology, Center for Promotion of International Education and Research, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
- Research Center for Pre-clinical and Clinical Medicine, National Research and Innovation Agency Republic of Indonesia, Cibinong, Indonesia
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Maulana Malik Ibrahim State Islamic University, Batu, Indonesia
| | | | - Gita Vita Soraya
- Department of Biochemistry, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
- Department of Neurology, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Siti Kurniawati
- Department of Clinical Microbiology, Faculty of Medicine, Brawijaya University, Malang, Indonesia
| | - Lola Ayu Istifiani
- Department of Nutrition, Faculty of Medicine, Brawijaya University, Malang, Indonesia
| | | | - William Ka Fai Tse
- Laboratory of Developmental Disorders and Toxicology, Center for Promotion of International Education and Research, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| |
Collapse
|
3
|
Identification of three novel TCOF1 mutations in patients with Treacher Collins Syndrome. Hum Genome Var 2021; 8:36. [PMID: 34580285 PMCID: PMC8476508 DOI: 10.1038/s41439-021-00168-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 08/22/2021] [Accepted: 08/22/2021] [Indexed: 11/28/2022] Open
Abstract
Here we describe three novel TCOF1 mutations found in unrelated patients with Treacher Collins syndrome. These mutations include one deletion, NM_001135243.2:c.2604_2605delAG (p.Gly869Glufs*3), and two substitutions, NM_001135243.2:c.2575C>T (p.Gln859*) and NM_001135243.2:c.4111G>T (p.Glu1371*). These mutations cause shortening of a protein called Treacle in patients with features typical of TCS. Continuous identification of new mutations is important to expand the mutation base, which is helpful in the diagnosis of both patients and their families
Collapse
|
4
|
Marszałek-Kruk BA, Wójcicki P, Dowgierd K, Śmigiel R. Treacher Collins Syndrome: Genetics, Clinical Features and Management. Genes (Basel) 2021; 12:genes12091392. [PMID: 34573374 PMCID: PMC8470852 DOI: 10.3390/genes12091392] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/04/2021] [Accepted: 09/05/2021] [Indexed: 12/31/2022] Open
Abstract
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 TCOF1, POLR1D, POLR1C and POLR1B genes. Genetically, the TCOF1 gene contains 27 exons which encodes the Treacle protein. In TCOF1, 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.
Collapse
Affiliation(s)
- Bożena Anna Marszałek-Kruk
- Department of Genetics, Wroclaw University of Environmental and Life Sciences, 51-631 Wroclaw, Poland
- Correspondence: ; Tel.: +48-713205926
| | - Piotr Wójcicki
- Department of Plastic Surgery, Wroclaw Medical University, 50-367 Wroclaw, Poland;
| | - Krzysztof Dowgierd
- Head and Neck Surgery Clinic for Children and Young Adults, Department of Clinical Pediatrics, University of Warmia and Mazury, 10-561 Olsztyn, Poland;
| | - Robert Śmigiel
- Department of Pediatrics, Division Pediatric Propedeutics and Rare Disorders, Wroclaw Medical University, 51-618 Wroclaw, Poland;
| |
Collapse
|
5
|
Liu J, Lin P, Pang J, Jia Z, Peng Y, Xi H, Wu L, Li Z, Wang H. Identification of a novel gross deletion of TCOF1 in a Chinese prenatal case with Treacher Collins syndrome. Mol Genet Genomic Med 2020; 8:e1313. [PMID: 32543076 PMCID: PMC7434750 DOI: 10.1002/mgg3.1313] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/22/2020] [Accepted: 04/27/2020] [Indexed: 02/06/2023] Open
Abstract
Background Treacher Collins syndrome (TCS) is the most common mandibulofacial dysostosis with an autosomal dominant or rarely recessive manner of inheritance. It is still challenging to make a definite diagnosis for affected fetuses with TCS only depending on the ultrasound screening. Genetic tests can contribute to the accurate diagnosis for those prenatal cases. Methods Targeted exome sequencing was performed in a fetus of a Chinese family, who presenting an abnormal facial appearance by prenatal 2D and 3D ultrasound screening, including micrognathia, nasal bridge pit, and abnormal auricle. The result was validated with multiplex ligation‐dependent probe amplification (MLPA) and real‐time quantitative PCR (qPCR). Results A novel 2–6 exons deletion of TCOF1 gene was identified and confirmed by the MLPA and qPCR in the fetus, which was inherited from the affected father with similar facial anomalies. Conclusion The heterozygous deletion of 2–6 exons in TCOF1 results in the TCS of this Chinese family. Our findings not only enlarge the spectrum of mutations in TCOF1 gene, but also highlight the values of combination of ultrasound and genetics tests in diagnosis of craniofacial malformation‐related diseases during perinatal period.
Collapse
Affiliation(s)
- Jing Liu
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Changsha, Hunan, China
| | - Pengsiyuan Lin
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Jialun Pang
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Changsha, Hunan, China
| | - Zhengjun Jia
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Changsha, Hunan, China
| | - Ying Peng
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Changsha, Hunan, China
| | - Hui Xi
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Changsha, Hunan, China
| | - Lingqian Wu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Zhuo Li
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Hua Wang
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Changsha, Hunan, China
| |
Collapse
|
6
|
Li X, Su Y, Huang S, Gao B, Zhang D, Wang X, Gao Q, Pang H, Zhao Y, Yuan Y, Dai P. Genotype-phenotype variability in Chinese cases of Treacher Collins syndrome. Acta Otolaryngol 2019; 139:567-575. [PMID: 31107123 DOI: 10.1080/00016489.2019.1612530] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Background: Treacher Collins syndrome (TCS) is a clinically and genetically heterogeneous disorder of craniofacial development mainly caused by variants in TCOF1, POLR1D, and POLR1C. Objectives: This study examined the causative genes of five TCS cases. Materials and Methods: In this study, two familial cases and three sporadic cases clinically diagonsed with TCS are described. Mutational analysis in probands was performed by targeted next-generation sequencing (NGS). Mutations identified by NGS were further confirmed by Sanger sequencing or multiplex ligation-dependent probe amplification (MLPA). Results: A novel gross deletion (exons 9-13), a novel small deletion (c.381_382delAG), and two known deletions (c.4131_4135delAAAAG and c.2394_2395delAG) within TCOF1 as well as a known mutation (c.91C > T) in POLR1D were identified. These five cases exhibited high inter- and intra-familial phenotypic heterogeneity. Conclusion: This is the first report of Chinese TCS cases caused by a gross deletion within TCOF1 and mutations in POLR1D. In addition to expanding the spectrum of TCS-associated mutation in the Chinese population, our findings present the diversity of its clinical presentation. It is recommended that analyses such as NGS or MLPA capable of detecting large deletions be undertaken as a part of TCS molecular diagnosis.
Collapse
Affiliation(s)
- Xiaohong Li
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Yu Su
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Shasha Huang
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Bo Gao
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Dejun Zhang
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
- Department of Otolaryngology, Head and Neck Surgery, The Second Hospital of Jilin University, Changchun, China
| | - Xiaobin Wang
- Department of Bioinformatics, MyGenostics Inc., Beijing, China
| | - Qin Gao
- Department of Bioinformatics, MyGenostics Inc., Beijing, China
| | - Hong Pang
- Department of Genetics, Shenyang Women’s and Children’s Hospital, Shenyang, China
| | - Yan Zhao
- Department of Genetics, Shenyang Women’s and Children’s Hospital, Shenyang, China
| | - Yongyi Yuan
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Pu Dai
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| |
Collapse
|
7
|
Terrazas K, Dixon J, Trainor PA, Dixon MJ. Rare syndromes of the head and face: mandibulofacial and acrofacial dysostoses. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2017; 6:10.1002/wdev.263. [PMID: 28186364 PMCID: PMC5400673 DOI: 10.1002/wdev.263] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 10/26/2016] [Accepted: 11/21/2016] [Indexed: 12/13/2022]
Abstract
Craniofacial anomalies account for approximately one-third of all congenital birth defects reflecting the complexity of head and facial development. Craniofacial development is dependent upon a multipotent, migratory population of neural crest cells, which generate most of the bone and cartilage of the head and face. In this review, we discuss advances in our understanding of the pathogenesis of a specific array of craniofacial anomalies, termed facial dysostoses, which can be subdivided into mandibulofacial dysostosis, which present with craniofacial defects only, and acrofacial dysostosis, which encompasses both craniofacial and limb anomalies. In particular, we focus on Treacher Collins syndrome, Acrofacial Dysostosis-Cincinnati Type as well as Nager and Miller syndromes, and animal models that provide new insights into the molecular and cellular basis of these congenital syndromes. We emphasize the etiologic and pathogenetic similarities between these birth defects, specifically their unique deficiencies in global processes including ribosome biogenesis, DNA damage repair, and pre-mRNA splicing, all of which affect neural crest cell development and result in similar tissue-specific defects. WIREs Dev Biol 2017, 6:e263. doi: 10.1002/wdev.263 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Karla Terrazas
- Stowers Institute for Medical Research, 1000 E. 50th Street Kansas City, MO 64110, USA
| | - Jill Dixon
- Division of Dentistry, Faculty of Biology, Medicine & Health, Michael Smith Building, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Paul A Trainor
- Stowers Institute for Medical Research, 1000 E. 50th Street Kansas City, MO 64110, USA
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Michael J Dixon
- Division of Dentistry, Faculty of Biology, Medicine & Health, Michael Smith Building, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| |
Collapse
|
8
|
Ahmed MK, Ye X, Taub PJ. Review of the Genetic Basis of Jaw Malformations. J Pediatr Genet 2016; 5:209-219. [PMID: 27895973 DOI: 10.1055/s-0036-1593505] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 10/04/2015] [Indexed: 10/20/2022]
Abstract
Genetic etiologies for congenital anomalies of the facial skeleton, namely, the maxilla and mandible, are important to understand and recognize. Malocclusions occur when there exist any significant deviation from what is considered a normal relationship between the upper jaw (maxilla) and the lower jaw (mandible). They may be the result of anomalies of the teeth alone, the bones alone, or both. A number of genes play a role in the facial skeletal development and are regulated by a host of additional regulatory molecules. As such, numerous craniofacial syndromes specifically affect the development of the jaws. The following review discusses several genetic anomalies that specifically affect the bones of the craniofacial skeleton and lead to malocclusion.
Collapse
Affiliation(s)
- Mairaj K Ahmed
- Department of Dentistry/Oral & Maxillofacial Surgery, Icahn School of Medicine at Mount Sinai, New York, New York, United States; Department of Otolaryngology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Xiaoqian Ye
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Peter J Taub
- Division of Plastic and Reconstructive Surgery, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| |
Collapse
|
9
|
A Mouse Model for Imprinting of the Human Retinoblastoma Gene. PLoS One 2015; 10:e0134672. [PMID: 26275142 PMCID: PMC4537222 DOI: 10.1371/journal.pone.0134672] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 07/13/2015] [Indexed: 12/21/2022] Open
Abstract
The human RB1 gene is imprinted due to integration of the PPP1R26P1 pseudogene into intron 2. PPP1R26P1 harbors the gametic differentially methylated region of the RB1 gene, CpG85, which is methylated in the female germ line. The paternally unmethylated CpG85 acts as promoter for the alternative transcript 2B of RB1, which interferes with expression of full-length RB1 in cis. In mice, PPP1R26P1 is not present in the Rb1 gene and Rb1 is not imprinted. Assuming that the mechanisms responsible for genomic imprinting are conserved, we investigated if imprinting of mouse Rb1 can be induced by transferring human PPP1R26P1 into mouse Rb1. We generated humanized Rb1_PPP1R26P1 knock-in mice that pass human PPP1R26P1 through the mouse germ line. We found that the function of unmethylated CpG85 as promoter for an alternative Rb1 transcript and as cis-repressor of the main Rb1 transcript is maintained in mouse tissues. However, CpG85 is not recognized as a gametic differentially methylated region in the mouse germ line. DNA methylation at CpG85 is acquired only in tissues of neuroectodermal origin, independent of parental transmission of PPP1R26P1. Absence of CpG85 methylation in oocytes and sperm implies a failure of imprint methylation establishment in the germ line. Our results indicate that site-specific integration of a proven human gametic differentially methylated region is not sufficient for acquisition of DNA methylation in the mouse germ line, even if promoter function of the element is maintained. This suggests a considerable dependency of DNA methylation induction on the surrounding sequence. However, our model is suited to determine the cellular function of the alternative Rb1 transcript.
Collapse
|
10
|
Treacher Collins syndrome: a clinical and molecular study based on a large series of patients. Genet Med 2015; 18:49-56. [PMID: 25790162 DOI: 10.1038/gim.2015.29] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Accepted: 01/28/2015] [Indexed: 01/01/2023] Open
Abstract
PURPOSE Treacher Collins/Franceschetti syndrome (TCS; OMIM 154500) is a disorder of craniofacial development belonging to the heterogeneous group of mandibulofacial dysostoses. TCS is classically characterized by bilateral mandibular and malar hypoplasia, downward-slanting palpebral fissures, and microtia. To date, three genes have been identified in TCS:,TCOF1, POLR1D, and POLR1C. METHODS We report a clinical and extensive molecular study, including TCOF1, POLR1D, POLR1C, and EFTUD2 genes, in a series of 146 patients with TCS. Phenotype-genotype correlations were investigated for 19 clinical features, between TCOF1 and POLR1D, and the type of mutation or its localization in the TCOF1 gene. RESULTS We identified 92/146 patients (63%) with a molecular anomaly within TCOF1, 9/146 (6%) within POLR1D, and none within POLR1C. Among the atypical negative patients (with intellectual disability and/or microcephaly), we identified four patients carrying a mutation in EFTUD2 and two patients with 5q32 deletion encompassing TCOF1 and CAMK2A in particular. Congenital cardiac defects occurred more frequently among patients with TCOF1 mutation (7/92, 8%) than reported in the literature. CONCLUSION Even though TCOF1 and POLR1D were associated with extreme clinical variability, we found no phenotype-genotype correlation. In cases with a typical phenotype of TCS, 6/146 (4%) remained with an unidentified molecular defect.
Collapse
|
11
|
Beygo J, Ammerpohl O, Gritzan D, Heitmann M, Rademacher K, Richter J, Caliebe A, Siebert R, Horsthemke B, Buiting K. Deep bisulfite sequencing of aberrantly methylated loci in a patient with multiple methylation defects. PLoS One 2013; 8:e76953. [PMID: 24130816 PMCID: PMC3793946 DOI: 10.1371/journal.pone.0076953] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 08/28/2013] [Indexed: 12/17/2022] Open
Abstract
NLRP7 is a maternal effect gene as maternal mutations in this gene cause recurrent hydatidiform moles, spontaneous abortions and stillbirths, whereas live births are very rare. We have studied a patient with multiple anomalies born to a mother with a heterozygous NLRP7 mutation. By array-based CpG methylation analysis of blood DNA from the patient, his parents and 18 normal controls on Illumina Infinium HumanMethylation27 BeadChips we found that the patient had methylation changes (delta ß ≥ 0.3) at many imprinted loci as well as at 87 CpGs associated with 85 genes of unknown imprinting status. Using a pseudoproband (permutation) approach, we found methylation changes at only 7-24 CpGs (mean 15; standard deviation 4.84) in the controls. Thus, the number of abberantly methylated CpGs in the patient is more than 14 standard deviations higher. In order to identify novel imprinted genes among the 85 conspicuous genes in the patient, we selected 19 (mainly hypomethylated) genes for deep bisulfite amplicon sequencing on the ROCHE/454 Genome Sequencer in the patient and at least two additional controls. These controls had not been included in the array analysis and were heterozygous for a single nucleotide polymorphism at the test locus, so that allele-specific DNA methylation patterns could be determined. Apart from FAM50B, which we proved to be imprinted in blood, we did not observe allele-specific DNA methylation at the other 18 loci. We conclude that the patient does not only have methylation defects at imprinted loci but (at least in blood) also an excess of methylation changes at apparently non-imprinted loci.
Collapse
Affiliation(s)
- Jasmin Beygo
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Ole Ammerpohl
- Institute of Human Genetics, Christian-Albrechts-University Kiel & University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Daniela Gritzan
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Melanie Heitmann
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Katrin Rademacher
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Julia Richter
- Institute of Human Genetics, Christian-Albrechts-University Kiel & University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Almuth Caliebe
- Institute of Human Genetics, Christian-Albrechts-University Kiel & University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Reiner Siebert
- Institute of Human Genetics, Christian-Albrechts-University Kiel & University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Bernhard Horsthemke
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
- * E-mail:
| | - Karin Buiting
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| |
Collapse
|
12
|
Steenpass L, Kanber D, Hiber M, Buiting K, Horsthemke B, Lohmann D. Human PPP1R26P1 functions as cis-repressive element in mouse Rb1. PLoS One 2013; 8:e74159. [PMID: 24019952 PMCID: PMC3760807 DOI: 10.1371/journal.pone.0074159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 07/26/2013] [Indexed: 01/26/2023] Open
Abstract
The human retinoblastoma gene (RB1) is imprinted; the mouse Rb1 gene is not. Imprinted expression of RB1 is due to differential methylation of a CpG island (CpG85), which is located in the pseudogene PPP1R26P1 in intron 2 of RB1. CpG85 serves as promoter for an alternative RB1 transcript, which is expressed from the unmethylated paternal allele only and is thought to suppress expression of the full-length RB1 transcript in cis. PPP1R26P1 contains another CpG island (CpG42), which is biallelically methylated. To determine the influence of PPP1R26P1 on RB1 expression, we generated an in vitro murine embryonic stem cell model by introducing human PPP1R26P1 into mouse Rb1. Next generation bisulfite sequencing of CpG85 and CpG42 revealed differences in their susceptibility to DNA methylation, gaining methylation at a median level of 4% and 18%, respectively. We showed binding of RNA polymerase II at and transcription from the unmethylated CpG85 in PPP1R26P1 and observed reduced expression of full-length Rb1 from the targeted allele. Our results identify human PPP1R26P1 as a cis-repressive element and support a connection between retrotransposition of PPP1R26P1 into human RB1 and the reduced expression of RB1 on the paternal allele.
Collapse
Affiliation(s)
- Laura Steenpass
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
- * E-mail:
| | - Deniz Kanber
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Michaela Hiber
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Karin Buiting
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Bernhard Horsthemke
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Dietmar Lohmann
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| |
Collapse
|
13
|
Vincent M, Collet C, Verloes A, Lambert L, Herlin C, Blanchet C, Sanchez E, Drunat S, Vigneron J, Laplanche JL, Puechberty J, Sarda P, Geneviève D. Large deletions encompassing the TCOF1 and CAMK2A genes are responsible for Treacher Collins syndrome with intellectual disability. Eur J Hum Genet 2013; 22:52-6. [PMID: 23695276 DOI: 10.1038/ejhg.2013.98] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 04/08/2013] [Accepted: 04/10/2013] [Indexed: 02/07/2023] Open
Abstract
Mandibulofacial dysostosis is part of a clinically and genetically heterogeneous group of disorders of craniofacial development, which lead to malar and mandibular hypoplasia. Treacher Collins syndrome is the major cause of mandibulofacial dysostosis and is due to mutations in the TCOF1 gene. Usually patients with Treacher Collins syndrome do not present with intellectual disability. Recently, the EFTUD2 gene was identified in patients with mandibulofacial dysostosis associated with microcephaly, intellectual disability and esophageal atresia. We report on two patients presenting with mandibulofacial dysostosis characteristic of Treacher Collins syndrome, but associated with unexpected intellectual disability, due to a large deletion encompassing several genes including the TCOF1 gene. We discuss the involvement of the other deleted genes such as CAMK2A or SLC6A7 in the cognitive development delay of the patients reported, and we propose the systematic investigation for 5q32 deletion when intellectual disability is associated with Treacher Collins syndrome.
Collapse
Affiliation(s)
- Marie Vincent
- Département de Génétique Médicale, CHRU Montpellier, Faculté de Médecine de Montpellier-Mimes, Université Montpellier 1, Montpellier, France
| | - Corinne Collet
- Service de Biologie Moléculaire, Hôpital Lariboisière, Paris, France
| | - Alain Verloes
- Département de Génétique Médicale, Hôpital Robert Debré, Paris, France, Université Denis Diderot Sorbonne-Paris, INSERM U676, Département de Génétique, Sart Tilman University Hospital, Liège, Belgium
| | - Laetitia Lambert
- Service de Génétique Médicale, CHRU de Nancy-Brabois, Nancy, France
| | - Christian Herlin
- Service de Chirurgie Plastique Infantile, CHRU Montpellier, Montpellier, France
| | | | - Elodie Sanchez
- Département de Génétique Médicale, CHRU Montpellier, Faculté de Médecine de Montpellier-Mimes, Université Montpellier 1, Montpellier, France
| | - Séverine Drunat
- Département de Génétique Médicale, Hôpital Robert Debré, Paris, France, Université Denis Diderot Sorbonne-Paris, INSERM U676, Département de Génétique, Sart Tilman University Hospital, Liège, Belgium
| | | | | | - Jacques Puechberty
- Département de Génétique Médicale, CHRU Montpellier, Faculté de Médecine de Montpellier-Mimes, Université Montpellier 1, Montpellier, France
| | - Pierre Sarda
- Département de Génétique Médicale, CHRU Montpellier, Faculté de Médecine de Montpellier-Mimes, Université Montpellier 1, Montpellier, France
| | - David Geneviève
- Département de Génétique Médicale, CHRU Montpellier, Faculté de Médecine de Montpellier-Mimes, Université Montpellier 1, Montpellier, France
| |
Collapse
|
14
|
Wieczorek D. Human facial dysostoses. Clin Genet 2013; 83:499-510. [PMID: 23565775 DOI: 10.1111/cge.12123] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 02/08/2013] [Accepted: 02/12/2013] [Indexed: 12/22/2022]
Abstract
The human facial dysostoses can be subdivided into mandibulofacial dysostoses (MFDs) and acrofacial dysostoses (AFDs). The craniofacial phenotypes of the two groups of patients are similar. Both types are thought to be related to abnormal migration of neural crest cells to the pharyngeal arches and the face. The craniofacial anomalies shared by the two groups consist of downslanting palpebral fissures, coloboma of the lower eyelid, from which the eyelashes medial to the defect may be absent, hypoplasia of the zygomatic complex, micrognathia, and microtia, which is often associated with hearing loss. These facial deformities are associated with limb anomalies in the AFDs. All MFDs present with the typical craniofacial phenotype, but some have additional features that help to distinguish them clinically: intellectual disability, microcephaly, chest deformity, ptosis, cleft lip/palate, macroblepharon, or blepharophimosis. The limb anomalies in the AFDs can be classified into pre-axial, post-axial, and others not fitting into the first two AFD types. Of the pre-axial types, Nager syndrome and of the post-axial types, Miller syndrome are the best-known disorders of their AFD subgroups. Several other AFDs with unknown molecular genetic bases, including lethal ones, have been described. This article reviews the MFDs and AFDs published to date.
Collapse
Affiliation(s)
- D Wieczorek
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany.
| |
Collapse
|
15
|
Treacher Collins syndrome: clinical implications for the paediatrician--a new mutation in a severely affected newborn and comparison with three further patients with the same mutation, and review of the literature. Eur J Pediatr 2012; 171:1611-8. [PMID: 22729243 DOI: 10.1007/s00431-012-1776-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Accepted: 06/10/2012] [Indexed: 10/28/2022]
Abstract
UNLABELLED Treacher Collins syndrome (TCS) is the most common and well-known mandibulofacial dysostosis caused by mutations in at least three genes involved in pre-rRNA transcription, the TCOF1, POLR1D and POLR1C genes. We present a severely affected male individual with TCS with a heterozygous de novo frameshift mutation within the TCOF1 gene (c.790_791delAG,p.Ser264GlnfsX7) and compare the clinical findings with three previously unpublished, milder affected individuals from two families with the same mutation. We elucidate typical clinical features of TCS and its clinical implications for the paediatrician and mandibulofacial surgeon, especially in severely affected individuals and give a short review of the literature. CONCLUSION The clinical data of these three families illustrate that the phenotype associated with this specific mutation has a wide intra- and interfamilial variability, which confirms that variable expressivity in carriers of TCOF1 mutations is not a simple consequence of the mutation but might be modified by the combination of genetic, environmental and stochastic factors. Being such a highly complex disease treatment of individuals with TCS should be tailored to the specific needs of each individual, preferably by a multidisciplinary team consisting of paediatricians, craniofacial surgeons and geneticists.
Collapse
|