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Kushwaha S, Stinnett V, Zou YS, Murry JB. Live-born autosomal ring chromosomes at the Johns Hopkins Hospital Cytogenomics Laboratory: Case series-Spanning 52 years of experience in a single center. Am J Med Genet A 2024; 194:253-267. [PMID: 37807876 DOI: 10.1002/ajmg.a.63429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/29/2023] [Accepted: 09/20/2023] [Indexed: 10/10/2023]
Abstract
Ring chromosomes (RCs) are a structural aberration that can be tolerated better in acrocentric or gonosomal chromosomes. Complete RCs arise from telomere-telomere fusions. Alternatively, genomic imbalances corresponding to the ends of the chromosomal arms can be seen with RC formation. RCs are unstable in mitosis, result in mosaicism, and are associated with a "ring syndrome," which presents with growth and development phenotypes and differs from those features more frequently observed with pure terminal copy number changes. Due to variability in mosaicism, size, and genomic content, clear genotype-phenotype correlations may not always be possible. Given the rarity of RCs, this historical data is invaluable. We performed a retrospective review of individuals bearing RCs to investigate the incidence in our laboratory. This work details the methods and features seen in association with twenty-three autosomal RCs. In decreasing order, the most frequently seen autosomal RCs were 18, 22, 4, 13, 17, and 9. The additional cases detail clinical and cytogenomic events similar to those reported in RCs. As methodologies advance, insights may be gleaned from following up on these cases to improve genotype-phenotype correlations and understand the cryptic differences or other predisposing factors that lead to ring formation and development.
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Affiliation(s)
- Shivani Kushwaha
- Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Victoria Stinnett
- Johns Hopkins Genomics, Baltimore, Maryland, USA
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Cytogenetics Laboratory, Johns Hopkins Hospital, Baltimore, Maryland, USA
| | - Ying S Zou
- Johns Hopkins Genomics, Baltimore, Maryland, USA
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Cytogenetics Laboratory, Johns Hopkins Hospital, Baltimore, Maryland, USA
| | - Jaclyn B Murry
- Johns Hopkins Genomics, Baltimore, Maryland, USA
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Cytogenetics Laboratory, Johns Hopkins Hospital, Baltimore, Maryland, USA
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Nagamine R, Kawasaki M, Kim KI, Sakai A, Suguro T. The posterior tibial slope is mainly created by the posterior rotation of the tibial condyles. J Orthop Surg (Hong Kong) 2021; 28:2309499020975580. [PMID: 33272082 DOI: 10.1177/2309499020975580] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
PURPOSE Constitutional varus in the coronal plane is formed based on the Hueter-Volkmann's law. The varus deformity occurs at the proximal metaphysis of the tibia and the tibial condyle rotates medially. In the sagittal plane, we hypothesized that the posterior slope angle of the tibial articular surface may also occur at the proximal metaphysis and the tibial condyle rotates posteriorly. The purpose of this study was to verify the hypothesis. METHODS A total of 208 patients who underwent TKA had lateral view proximal tibia digital radiograph on which seven parameters were analyzed. The posterior slope angle of the tibial articular surface relative to the anterior wall of the tibial condyle and that relative to the anterior cortex of the tibial shaft were assessed. Correlation between the position of the tibial condyle and the posterior slope angle of the articular surface were assessed. RESULTS The proximal tibial condyle itself did not have a posterior slope in the 86.5% of the participants. Posterior rotation of the tibial condyle created posterior slope of the tibial articular surface relative to the anterior cortex of the tibial shaft. The more tibial condyle was posteriorly rotated, the more the tibial articular surface shifted posteriorly. CONCLUSION Study findings showed that the posterior tibial slope occurs at the proximal metaphysis of the tibia, and the tibial condyle rotates posteriorly. The posterior tibial slope involves the posterior shift of the tibial articular surface. The posterior tibial slope is mainly created by the posterior rotation of the tibial condyle.
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Affiliation(s)
- Ryuji Nagamine
- Center of Artificial Joint and Rheumatism, Fukuoka Tokushukai Medical Center, Fukuoka, Japan
| | - Makoto Kawasaki
- Department of Orthopaedic Surgery, School of Medicine, University of Occupational and Environmental Health, Fukuoka, Japan
| | - Kang-Il Kim
- Department of Orthopaedic Surgery, School of Medicine, Kyung Hee University, Seoul, Korea
| | - Akinori Sakai
- Department of Orthopaedic Surgery, School of Medicine, University of Occupational and Environmental Health, Fukuoka, Japan
| | - Toru Suguro
- Japan Research Institute of Artificial Joint, Kisarazu, Japan
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Abstract
Dual configurational and constitutional dynamics in systems based on enamine molecular switches has been systematically studied. pH-responsive moieties, such as 2-pyridyl and 2-quinolinyl units, were required on the "stator" part, also providing enamine stability through intramolecular hydrogen-bonding (IMHB) effects. Upon protonation or deprotonation, forward and backward switching could be rapidly achieved. Extension of the stator π-system in the 2-quinolinyl derivative provided a higher E-isomeric equilibrium ratio under neutral conditions, pointing to a means to achieve quantitative forward/backward isomerization processes. The "rotor" part of the enamine switches exhibited constitutional exchange ability with primary amines. Interestingly, considerably higher exchange rates were observed with amines containing ester groups, indicating potential stabilization of the transition state through IMHB. Acids, particularly BiIII , were found to efficiently catalyze the constitutional dynamic processes. In contrast, the enamine and the formed dynamic enamine system showed excellent stability under basic conditions. This coupled configurational and constitutional dynamics expands the scope of dynamic C-C and C-N bonds and potentiates further studies and applications in the fields of molecular machinery and systems chemistry.
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Affiliation(s)
- Yansong Ren
- Department of ChemistryKTH—Royal Institute of TechnologyTeknikringen 3610044StockholmSweden
| | - Oleksandr Kravchenko
- Department of ChemistryKTH—Royal Institute of TechnologyTeknikringen 3610044StockholmSweden
| | - Olof Ramström
- Department of ChemistryKTH—Royal Institute of TechnologyTeknikringen 3610044StockholmSweden
- Department of ChemistryUniversity of Massachusetts LowellOne University Ave.LowellMA01854USA
- Department of Chemistry and Biomedical SciencesLinnaeus University39182KalmarSweden
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Vincenot A, Saultier P, Kunishima S, Poggi M, Hurtaud-Roux MF, Roussel A, Actn Study Coinvestigators, Schlegel N, Alessi MC. Novel ACTN1 variants in cases of thrombocytopenia. Hum Mutat 2019; 40:2258-2269. [PMID: 31237726 PMCID: PMC6900141 DOI: 10.1002/humu.23840] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 05/10/2019] [Accepted: 05/28/2019] [Indexed: 11/11/2022]
Abstract
The ACTN1 gene has been implicated in inherited macrothrombocytopenia. To decipher the spectrum of variants and phenotype of ACTN1‐related thrombocytopenia, we sequenced the ACTN1 gene in 272 cases of unexplained chronic or familial thrombocytopenia. We identified 15 rare, monoallelic, nonsynonymous and likely pathogenic ACTN1 variants in 20 index cases from 20 unrelated families. Thirty‐one family members exhibited thrombocytopenia. Targeted sequencing was carried out on 12 affected relatives, which confirmed presence of the variant. Twenty‐eight of 32 cases with monoallelic ACTN1 variants had mild to no bleeding complications. Eleven cases harbored 11 different unreported ACTN1 variants that were monoallelic and likely pathogenic. Nine variants were located in the α‐actinin‐1 (ACTN1) rod domain and were predicted to hinder dimer formation. These variants displayed a smaller increase in platelet size compared with variants located outside the rod domain. In vitro expression of the new ACTN1 variants induced actin network disorganization and led to increased thickness of actin fibers. These findings expand the repertoire of ACTN1 variants associated with thrombocytopenia and highlight the high frequency of ACTN1‐related thrombocytopenia cases. The rod domain, like other ACTN1 functional domains, may be mutated resulting in actin disorganization in vitro and thrombocytopenia with normal platelet size in most cases.
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Affiliation(s)
- Anne Vincenot
- CHU Robert Debré, National Reference Center for Inherited Platelet Disorders and Biological Hematology Service, AP-HP, Paris, France
| | - Paul Saultier
- Aix-Marseille Univ, INSERM, INRA, C2VN, Marseille, France
| | - Shinji Kunishima
- Department of Medical Technology, Gifu University of Medical Science, Seki, Gifu, Japan
| | - Marjorie Poggi
- Aix-Marseille Univ, INSERM, INRA, C2VN, Marseille, France
| | - Marie-Françoise Hurtaud-Roux
- CHU Robert Debré, National Reference Center for Inherited Platelet Disorders and Biological Hematology Service, AP-HP, Paris, France
| | - Alain Roussel
- Aix Marseille University, CNRS, AFMB, Marseille, France
| | | | - Nicole Schlegel
- CHU Robert Debré, National Reference Center for Inherited Platelet Disorders and Biological Hematology Service, AP-HP, Paris, France
| | - Marie-Christine Alessi
- Aix-Marseille Univ, INSERM, INRA, C2VN, Marseille, France.,APHM, CHU Timone, French Reference Center for Inherited Platelet Disorders, Marseille, France
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Abstract
Chromosome analysis is one of the first approaches to genetic testing and remains a key component of genetic analysis of constitutional and somatic genetic disorders. Numerical or unbalanced structural chromosome abnormalities usually lead to multiple congenital anomalies. Sometimes these are compatible with live birth, usually resulting in severe cognitive and physical handicaps; other times they result in miscarriage or stillbirth. Chromosome rearrangements also occur as somatic changes in malignancies. Identification of constitutional chromosomal anomalies (anomalies present in most or all cells of the body and/or the germline) can provide important information for genetic counseling. In this unit, we introduce chromosomal microarray analysis (CMA), which is a relatively recent addition to cytogenetic technologies, and has become the recommended first-tier testing method for patients with developmental delay, intellectual disability, autism, and/or multiple congenital anomalies. We also discuss non-invasive prenatal testing/screening (NIPTS), which uses circulating cell-free fetal DNA (cfDNA) from maternal plasma to rapidly screen for autosomal and sex-chromosome aneuploidies. Cytogenetic analysis of tumors is helpful in diagnosis and in monitoring the effects of treatment. The protocols in this chapter cover the clinical study of chromosomes in nonmalignant tissues.
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Affiliation(s)
- Patrick R Gonzales
- Cytogenetics Laboratory, Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Andrew J Carroll
- Cytogenetics Laboratory, Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Bruce R Korf
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama
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Robberecht C, Voet T, Utine GE, Schinzel A, de Leeuw N, Fryns JP, Vermeesch J. Meiotic errors followed by two parallel postzygotic trisomy rescue events are a frequent cause of constitutional segmental mosaicism. Mol Cytogenet 2012; 5:19. [PMID: 22490612 PMCID: PMC3350457 DOI: 10.1186/1755-8166-5-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 04/10/2012] [Indexed: 01/27/2023] Open
Abstract
Structural copy number variation (CNV) is a frequent cause of human variation and disease. Evidence is mounting that somatic acquired CNVs are prevalent, with mosaicisms of large segmental CNVs in blood found in up to one percent of both the healthy and patient populations. It is generally accepted that such constitutional mosaicisms are derived from postzygotic somatic mutations. However, few studies have tested this assumption. Here we determined the origin of CNVs which coexist with a normal cell line in nine individuals. We show that in 2/9 the CNV originated during meiosis. The existence of two cell lines with 46 chromosomes thus resulted from two parallel trisomy rescue events during postzygotic mitoses.
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Affiliation(s)
| | - Thierry Voet
- Department of Human Genetics, Catholic University Leuven, Leuven, Belgium
| | - Gülen E Utine
- Department of Human Genetics, Catholic University Leuven, Leuven, Belgium
- Department of Pediatrics, Division of Genetics, Hacettepe University, Ankara, Turkey
| | - Albert Schinzel
- Institute of Medical Genetics, University of Zürich, Zürich, Switzerland
| | - Nicole de Leeuw
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - Jean-Pierre Fryns
- Department of Human Genetics, Catholic University Leuven, Leuven, Belgium
| | - Joris Vermeesch
- Department of Human Genetics, Catholic University Leuven, Leuven, Belgium
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