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McCrary T, Hughes T, Brook AH, Paul KS. Mirror, mirror? An evaluation of identical twin mirroring in tooth crown morphology. Anat Rec (Hoboken) 2024. [PMID: 38372073 DOI: 10.1002/ar.25408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/30/2024] [Accepted: 01/31/2024] [Indexed: 02/20/2024]
Abstract
It has been estimated that 25% of monozygotic ("identical") twin pairs exhibit reverse asymmetry (RA) or "mirroring" of minor anatomical features as a result of delayed zygote division. Here, we examine whether identical twin mirroring accounts for patterns of dental asymmetry in a sample of monozygotic and dizygotic ("fraternal") twins. We focus on crown morphology to approach the following question: is there an association between dental RA frequency and twin type suggestive of the presence of mirror image twins in our sample? Data were collected from 208 deciduous and 196 permanent dentitions of participants of the University of Adelaide Twin Study using Arizona State University Dental Anthropology System standards. RA frequencies were compared across morphological complexes (deciduous, permanent), twin types (monozygotic, dizygotic), and traits. Fisher's exact tests were performed to formally evaluate the association between twin type and dental RA. Across the entire dataset, RA rates failed to exceed 8% for any twin type. In monozygotic twins, deciduous mirroring totaled 5.3% of observed cases, while permanent mirroring totaled 7.8% of observed cases. We found no statistically significant association between RA and twin type for any morphological character (p-value range: 0.07-1.00). Our results suggest the timing of monozygotic twin division does not explain the structure of asymmetry for our morphology dataset and that published estimates of identical twin mirroring rates may be inflated or contingent upon phenotype. Instead, rates reported for this sample more closely align with the proposed etiology of this condition.
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Affiliation(s)
- Tess McCrary
- Department of Anthropology, University of Arkansas, Fayetteville, Arkansas, USA
- University of Tennessee Health Science Center, College of Dentistry, Memphis, Tennessee, USA
| | - Toby Hughes
- Adelaide Dental School, The University of Adelaide, Adelaide, SA, Australia
| | - Alan H Brook
- Adelaide Dental School, The University of Adelaide, Adelaide, SA, Australia
- Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Kathleen S Paul
- Department of Anthropology, University of Arkansas, Fayetteville, Arkansas, USA
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2
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Toh AQJ, Becking AG, Leung YY. Mirror-image unilateral condylar hyperplasia in monozygotic twins. Int J Oral Maxillofac Surg 2020; 50:1177-1181. [PMID: 33386203 DOI: 10.1016/j.ijom.2020.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/08/2020] [Accepted: 12/04/2020] [Indexed: 11/16/2022]
Abstract
Unilateral condylar hyperplasia (UCH) is an abnormal growth process that results in the development of mandibular asymmetry. The aetiopathogenesis of this entity is still unclear. Various factors including hormonal influences, intrauterine factors, trauma, infection, and genetics have been speculated to lead to the development of UCH. In genetic epidemiology, twins have been a valuable resource for investigating the genetic basis of complex traits and diseases. We present a case of mirror-image UCH in a pair of monozygotic twins, providing evidence of a possible genetic link for this mandibular growth disorder. The concordance in the monozygotic twins appears to be reflected by the precise mirror-image presentation of the congenital dentofacial anomalies. Further twin studies would be useful in clarifying the contributions of genetic and environmental factors to the presence and development of UCH.
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Affiliation(s)
- A Q J Toh
- Oral and Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong
| | - A G Becking
- Department of Oral and Maxillofacial Surgery, Amsterdam University Medical Centre/AMC and Academic Centre for Dentistry (ACTA), Amsterdam, The Netherlands
| | - Y Y Leung
- Oral and Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong.
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3
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Ponnudurai R, Shajahan I, Rani A, Jayakar J. Mirror finger patterns of apparent monozygotic twins and sib pairs with Schizophrenia. Indian J Psychiatry 2019; 61:520-525. [PMID: 31579182 PMCID: PMC6767825 DOI: 10.4103/psychiatry.indianjpsychiatry_476_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Although mirror images are noted in some twins, no such reports are available for twins and subjects with schizophrenia. AIM The study was to assess the occurrence of mirror image finger patterns in apparent monozygotic twins with schizophrenia. Another objective was to elucidate these characteristics among sib pairs with schizophrenia for comparison with those of the twins. MATERIALS AND METHODS Eight apparent monozygotic twin pairs and eight sib pairs with schizophrenia were investigated. The frequency of identical patterns in the right side finger of one twin and the corresponding left side finger of the other twin was assessed, and similarly on other sides. Similar assessment was made in sib pairs with schizophrenia and normal sib pairs. RESULTS The left middle finger pattern of one of the twin pair was found to be the mirror image of the right middle finger of the other twin in all the twin pairs studied and so was in seven of the sib pairs with schizophrenia. These mirror images of sib pairs with schizophrenia was more than those of normal sib pairs. This difference was accentuated with significantly more of these patterns in the twins in comparison to those among normal sib pairs. Notably, no difference emerged between the sib pairs with schizophrenia and the twins in any of their finger pairs. CONCLUSION Mirror images that are probably due to factors like abnormal genotypes and L- DNA, appear to be promising tools to study the etiology of schizophrenia.
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Affiliation(s)
- R Ponnudurai
- Professor Emeritus, Department of Psychiatry, A.C.S. Medical College and Hospital, Chennai, Tamil Nadu, India.,Formerly Director, Institute of Mental Health, Chennai, Tamil Nadu, India.,Formerly Professor, Department of Psychiatry, Madras Medical College and Government General Hospital, Sri Ramachandra Medical College and Research Institute, Chennai, Tamil Nadu, India
| | - I Shajahan
- Consultant Psychiatrist, Wigan North Recovery Team, Clare House, Phoenix Way, Ince, Wigan WN3 4NW, UK.,Formerly Professor, Institute of Mental Health, Madras Medical College, Chennai, Tamil Nadu, India
| | - A Rani
- Department of Psychiatry, Government Medical College, Ernakulam, Kerala, India
| | - J Jayakar
- Formerly Professor, Institute of Mental Health, Madras Medical College, Chennai, Tamil Nadu, India
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4
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Pihlaja K, Vuollo V, Sidlauskas M, Harila V, Sidlauskas A, Salomskiene L, Heikkinen T. Relations of laterality and chewing sidedness in twins. Eur J Orthod 2019; 41:244-249. [PMID: 29982485 DOI: 10.1093/ejo/cjy050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVES To study, whether there are associations between chewing side preference and other lateralities, whether there is a genetic origin for preferred chewing side (PCS), relations to sex, birth order and orthodontic treatment. MATERIALS AND METHODS The study included 113 twin pairs, 57 pairs monozygotic, 47 pairs same sex dizygotic and 9 pairs of opposite sex. The lateralities of preferred chewing side, footedness and eyedness were assessed by functional tests and handedness was checked by asking. RESULTS Right-handed, -footed and -eyed as separated groups, and true-right sided (combined), were evenly distributed by preferred chewing side. By contrast, left-handed, -footed, -eyed and non-right sided used more left or both sides when chewing. Birth order affected preferred chewing side among monozygotic: the first-born twin was more likely to have the preferred chewing side on the non-right, whereas second-born twins used right side. Gender, zygosity and orthodontic treatment were not statistically significant factors. LIMITATIONS Examination of chewing sidedness could have been done in several different ways to provide a definite result. Sample size of opposite sex twins was very small. CONCLUSIONS Preferred chewing side generally seemed to follow the side where other lateralities occur; however, monozygotic twins seemed to be more receptive to it. True-right sided were more evenly distributed than non-right sided by the preferred chewing side.
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Affiliation(s)
- Kirsi Pihlaja
- Unit of Oral Health Sciences, Department of Orthodontics, University of Oulu, Oulu, Finland
| | - Ville Vuollo
- Unit of Oral Health Sciences, Department of Orthodontics, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, Oulu University Hospital, Oulu, Finland
| | - Mantas Sidlauskas
- Clinic of Orthodontics, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Virpi Harila
- Unit of Oral Health Sciences, Department of Orthodontics, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, Oulu University Hospital, Oulu, Finland
| | - Antanas Sidlauskas
- Clinic of Orthodontics, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Loreta Salomskiene
- Institute of Biology Systems and Genetics, Veterinary Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Tuomo Heikkinen
- Unit of Oral Health Sciences, Department of Orthodontics, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, Oulu University Hospital, Oulu, Finland
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5
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Takahashi M, Hosomichi K, Yamaguchi T, Nagahama R, Yoshida H, Marazita ML, Weinberg SM, Maki K, Tajima A. Exploration of genetic factors determining cleft side in a pair of monozygotic twins with mirror-image cleft lip and palate using whole-genome sequencing and comparison of craniofacial morphology. Arch Oral Biol 2018; 96:33-38. [PMID: 30172943 DOI: 10.1016/j.archoralbio.2018.08.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 08/15/2018] [Accepted: 08/17/2018] [Indexed: 12/15/2022]
Abstract
OBJECTIVE The aim of the present study is to explore genetic factors determining difference of cleft side using whole-genome sequencing and evaluation of craniofacial morphology using cephalometric analysis between Japanese monozygotic (MZ) twins with mirror-image cleft lip and palate (CLP). DESIGN We selected a Japanese MZ twin pair (MZ-A and MZ-B) affected with unilateral CLP who are discordant for cleft side (left/right) and conducted whole-genome sequencing to identify genetic factors determining cleft side. Moreover, we compared their craniofacial morphologies using cephalograms. RESULTS Whole-genome sequencing results suggested that no discordant DNA variants were found between MZ-A and MZ-B. The comparison of craniofacial morphology between the MZ twins revealed that MZ-B had maxillary deficiency and slightly more mandibular protrusion than MZ-A. CONCLUSIONS It is indicated that environmental factors might be a critical factor that influences the determination of difference of cleft side in orofacial clefts. In addition, we found some differences in craniofacial morphology between MZ-A and MZ-B. Our findings suggest that various environmental factors, such as epigenetics, might be a critical factor that influences the determination of difference of cleft side in CLP rather than inherited genetic factors.
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Affiliation(s)
- Masahiro Takahashi
- Department of Orthodontics, School of Dentistry, Showa University, Tokyo, Japan.
| | - Kazuyoshi Hosomichi
- Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Ishikawa, Japan
| | - Tetsutaro Yamaguchi
- Department of Orthodontics, School of Dentistry, Showa University, Tokyo, Japan; Center for Craniofacial and Dental Genetics, Department of Oral Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ryo Nagahama
- Department of Orthodontics, School of Dentistry, Showa University, Tokyo, Japan
| | - Hiroshi Yoshida
- Department of Orthodontics, School of Dentistry, Showa University, Tokyo, Japan
| | - Mary L Marazita
- Center for Craniofacial and Dental Genetics, Department of Oral Biology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA; Clinical and Translational Science Institute, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Seth M Weinberg
- Center for Craniofacial and Dental Genetics, Department of Oral Biology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Anthropology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Koutaro Maki
- Department of Orthodontics, School of Dentistry, Showa University, Tokyo, Japan
| | - Atsushi Tajima
- Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Ishikawa, Japan
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6
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McNamara HC, Kane SC, Craig JM, Short RV, Umstad MP. A review of the mechanisms and evidence for typical and atypical twinning. Am J Obstet Gynecol 2016; 214:172-191. [PMID: 26548710 DOI: 10.1016/j.ajog.2015.10.930] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 10/28/2015] [Accepted: 10/29/2015] [Indexed: 12/11/2022]
Abstract
The mechanisms responsible for twinning and disorders of twin gestations have been the subject of considerable interest by physicians and scientists, and cases of atypical twinning have called for a reexamination of the fundamental theories invoked to explain twin gestations. This article presents a review of the literature focusing on twinning and atypical twinning with an emphasis on the phenomena of chimeric twins, phenotypically discordant monozygotic twins, mirror-image twins, polar body twins, complete hydatidiform mole with a coexistent twin, vanishing twins, fetus papyraceus, fetus in fetu, superfetation, and superfecundation. The traditional models attributing monozygotic twinning to a fission event, and more recent models describing monozygotic twinning as a fusion event, are critically reviewed. Ethical restrictions on scientific experimentation with human embryos and the rarity of cases of atypical twinning have limited opportunities to elucidate the exact mechanisms by which these phenomena occur. Refinements in the modeling of early embryonic development in twin pregnancies may have significant clinical implications. The article includes a series of figures to illustrate the phenomena described.
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Affiliation(s)
- Helen C McNamara
- Department of Maternal-Fetal Medicine, Royal Womens Hospital, Melbourne, Victoria, Australia
| | - Stefan C Kane
- Department of Maternal-Fetal Medicine, Royal Womens Hospital, Melbourne, Victoria, Australia; Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Victoria, Australia
| | - Jeffrey M Craig
- Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Roger V Short
- Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Mark P Umstad
- Department of Maternal-Fetal Medicine, Royal Womens Hospital, Melbourne, Victoria, Australia; Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Victoria, Australia.
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7
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Lubala TK, Mbuyi-Musanzayi S, Lubala N, Luboya ON, Kalenga PM, Devriendt K, Lukusa-Tshilobo P. Mirror-image gastroschisis in monochorionic female twins. Eur J Med Genet 2015; 58:266-9. [DOI: 10.1016/j.ejmg.2015.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 03/08/2015] [Indexed: 11/29/2022]
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8
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Lenze U, Stolberg-Stolberg J, Pohlig F, Lenze F, von Eisenhart-Rothe R, Rechl H, Toepfer A. Unicameral Bone Cyst in the Calcaneus of Mirror Image Twins. J Foot Ankle Surg 2014; 54:754-7. [PMID: 25435010 DOI: 10.1053/j.jfas.2014.09.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Indexed: 02/03/2023]
Abstract
Unicameral bone cysts (UBCs) are benign tumor-like lesions that commonly occur in the diaphyseal or metaphyseal region of the long bones within the first 2 decades of life. Until today, the pathogenesis of UBC has been unclear, but mechanisms such as vascular occlusion or a response to trauma have been supposed. During the past decade, in particular, the genetic aspects of the development of this rare lesion have been discussed. We present the first case of mirror image monozygotic twins with a mirror image UBC of the calcaneus. Our findings reinforce the importance of additional studies to understand the significance of cytogenetic factors in the etiology of UBC.
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Affiliation(s)
- Ulrich Lenze
- Resident, Department of Orthopedics and Orthopedic Sports Medicine, Klinikum rechts der Isar, Technische Universtät München, Munich, Germany.
| | - Josef Stolberg-Stolberg
- Registrar, Department of Orthopedics and Orthopedic Sports Medicine, Klinikum rechts der Isar, Technische Universtät München, Munich, Germany
| | - Florian Pohlig
- Resident, Department of Orthopedics and Orthopedic Sports Medicine, Klinikum rechts der Isar, Technische Universtät München, Munich, Germany
| | - Florian Lenze
- Resident, Department of Orthopedics and Orthopedic Sports Medicine, Klinikum rechts der Isar, Technische Universtät München, Munich, Germany
| | - Rüdiger von Eisenhart-Rothe
- Professor, Department of Orthopedics and Orthopedic Sports Medicine, Klinikum rechts der Isar, Technische Universtät München, Munich, Germany
| | - Hans Rechl
- Professor, Department of Orthopedics and Orthopedic Sports Medicine, Klinikum rechts der Isar, Technische Universtät München, Munich, Germany
| | - Andreas Toepfer
- Surgeon, Department of Orthopedics and Orthopedic Sports Medicine, Klinikum rechts der Isar, Technische Universtät München, Munich, Germany
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9
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Ma K. Embryonic left-right separation mechanism allows confinement of mutation-induced phenotypes to one lateral body half of bilaterians. Am J Med Genet A 2013; 161A:3095-114. [PMID: 24254848 DOI: 10.1002/ajmg.a.36188] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 07/16/2013] [Indexed: 11/08/2022]
Abstract
A fundamental question in developmental biology is how a chimeric animal such as a bilateral gynandromorphic animal can have different phenotypes confined to different lateral body halves, and how mutation-induced phenotypes, such as genetic diseases, can be confined to one lateral body half in patients. Here, I propose that embryos of many, if not all, bilaterian animals are divided into left and right halves at a very early stage (which may vary among different types of animals), after which the descendants of the left-sided and right-sided cells will almost exclusively remain on their original sides, respectively, throughout the remaining development. This embryonic left-right separation mechanism allows (1) mutations and the mutation-induced phenotypes to be strictly confined to one lateral body half in animals and humans; (2) mothers with bilateral hereditary primary breast cancer to transmit their disease to their offspring at twofold of the rate compared to mothers with unilateral hereditary breast cancer; and (3) a mosaic embryo carrying genetic or epigenetic mutations to develop into either an individual with the mutation-induced phenotype confined unilaterally, or a pair of twins displaying complete, partial, or mirror-image discordance for the phenotype. Further, this left-right separation mechanism predicts that the two lateral halves of a patient carrying a unilateral genetic disease can each serve as a case and an internal control, respectively, for genetic and epigenetic comparative studies to identify the disease causations.
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10
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Hughes TE, Townsend GC, Pinkerton SK, Bockmann MR, Seow WK, Brook AH, Richards LC, Mihailidis S, Ranjitkar S, Lekkas D. The teeth and faces of twins: providing insights into dentofacial development and oral health for practising oral health professionals. Aust Dent J 2013; 59 Suppl 1:101-16. [DOI: 10.1111/adj.12101] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- TE Hughes
- School of Dentistry; The University of Adelaide; South Australia Australia
| | - GC Townsend
- School of Dentistry; The University of Adelaide; South Australia Australia
| | - SK Pinkerton
- School of Dentistry; The University of Adelaide; South Australia Australia
| | - MR Bockmann
- School of Dentistry; The University of Adelaide; South Australia Australia
| | - WK Seow
- School of Dentistry; The University of Queensland; Brisbane Australia
| | - AH Brook
- School of Dentistry; The University of Adelaide; South Australia Australia
- Institute of Dentistry; Queen Mary University of London; United Kingdom
| | - LC Richards
- School of Dentistry; The University of Adelaide; South Australia Australia
| | - S Mihailidis
- School of Dentistry; The University of Adelaide; South Australia Australia
| | - S Ranjitkar
- School of Dentistry; The University of Adelaide; South Australia Australia
| | - D Lekkas
- School of Dentistry; The University of Adelaide; South Australia Australia
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de Mooij T, Wuyts W, Ham J. Phenotypic Differences in Multiple Osteochondromas in Monozygotic Twins: A Case Report. JBJS Case Connect 2012; 2:e60. [PMID: 29252356 DOI: 10.2106/jbjs.cc.k.00134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Tristan de Mooij
- Department of Orthopaedic Surgery, Onze Lieve Vrouwe Gasthuis, P.O. Box 30.001, 1090 HM Amsterdam.
| | - Wim Wuyts
- Department of Medical Genetics, University and University Hospital of Antwerp, Prins Boudewijnlaan 43, 2650 Edegem, Belgium
| | - John Ham
- Department of Orthopaedic Surgery, Onze Lieve Vrouwe Gasthuis, P.O. Box 30.001, 1090 HM Amsterdam.
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12
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Riess A, Dufke A, Riess O, Beck-Woedl S, Fode B, Skladny H, Klaes R, Tzschach A. Mirror-image asymmetry in monozygotic twins with kabuki syndrome. Mol Syndromol 2012; 3:94-7. [PMID: 23326255 DOI: 10.1159/000341251] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2012] [Indexed: 01/10/2023] Open
Abstract
Kabuki syndrome (OMIM 147920) is a rare disorder characterised by moderate intellectual disability, growth retardation, microcephaly and characteristic facial dysmorphic features which comprise long palpebral fissures, eversion of the lateral third of the eyelids and arched eyebrows with lateral sparseness. Mutations in MLL2 are the most frequent cause of this disorder. More than 100 MLL2 point mutations have been reported, but large intragenic deletions comprising one or more exons have not yet been identified. We report on a pair of monozygotic twin brothers in whom a deletion of 2 neighbouring exons was detected. The twins had the characteristic facial features of Kabuki syndrome, and they suffered from microcephaly, cleft lip and palate and congenital heart disease. Cleft lip and palate were left-sided in the first twin and right-sided in the second twin, i.e. they represented a mirror-image asymmetry. The intragenic deletion in these brothers broadens the spectrum of MLL2 mutations, and they provide a rare example of mirror-image asymmetry of congenital malformations in monozygotic twins.
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Affiliation(s)
- A Riess
- Institute of Human Genetics, University of Tuebingen, Tuebingen, Germany
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13
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Pearsall-Jones JG, Piek JP, Rigoli D, Martin NC, Levy F. An Investigation Into Etiological Pathways of DCD and ADHD Using a Monozygotic Twin Design. Twin Res Hum Genet 2012; 12:381-91. [DOI: 10.1375/twin.12.4.381] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
AbstractWe previously described a co-twin control design using questionnaire data on monozygotic twins discordant and concordant for developmental coordination disorder (DCD) and attention deficit hyperactivity disorder (ADHD). Our results suggested that DCD and developmental ADHD had different causal pathways, and that second-born twins were at higher risk for oxygen perfusion problems than first-born twins. In the current study we further explored our findings using DNA confirmed zygosity and assessments of 4 female and 10 male sets of monozygotic twins, aged 8 to 17 years, from the first study. Using the McCarron Assessment of Neuromuscular Development (MAND), twice as many second- as first-born twins met criteria for DCD. Second-born twins attained significantly lower scores on 1-minute Apgar, MAND Gross Motor, Bimanual Dexterity and Neuromuscular Development Index. Seven of the nine twins who met criteria for DCD experienced perinatal oxygen perfusion problems. This supported findings in the first study of an association between perinatal oxygen perfusion problems and DCD, and our hypothesis that DCD and cerebral palsy have similar causal pathways. We found similar numbers of males and females discordant for DCD. On telephone interview using the Diagnostic Interview Schedule for Children Parent Interview, the only first-, and all five second-born twins who met criteria for ADHD had an inattentive component — three Inattentive; three Combined. All twins positive for ADHD were male. This adds support to our hypothesis that ADHD symptoms found in some participants may reflect secondary ADHD associated with environmental factors, rather than developmental ADHD.
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14
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ter Laan M, Kerstjens-Frederikse WS, Metzemaekers JDM, van Dijk JMC, Groen RJM. Concordant Symptomatic Intracranial Aneurysm in a Monozygotic Twin: A Case Report and Review of the Literature. Twin Res Hum Genet 2012; 12:295-300. [DOI: 10.1375/twin.12.3.295] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractThe development of an intracranial aneurysm (IA) is a multifactorial process, involving genetic and environmental factors. The presence of IA or aneurysmal subarachnoid hemorrhage (aSAH) in twins is particularly interesting, since both genetic and environmental factors can be studied. It also raises the question of whether, when one twin is affected, the other asymptomatic twin should be examined for an IA. We report on a monozygotic (MZ) twin-pair with aSAH in both twins and we review all reported cases of IA in MZ twins. Including our case, we found only 14 MZ twin-pairs in which both twins harbored an IA, suggesting a heavy underreporting in the medical literature. In this small group, a high concordance was noted in the sites of IAs. In MZ twins, the preferred sites for IAs are the branching arteries, while aneurysms arising from fusion arteries are rare. These sites differ from the preferential sites seen in series of familial IAs and series of sporadic IAs. We therefore hypothesize that the twinning process might play a significant role in the development of IAs in MZ twins. To further explore and substantiate this, the large twin registries should be studied. Although IAs in MZ twins with a negative family history for IAs should not be regarded as familial IAs, screening of the asymptomatic twin should be seriously considered if one MZ twin presents with an aSAH or an IA, because of the high fatality rates reported in asymptomatic (and not screened) MZ twin-halves.
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15
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Bilateral asymmetry of tooth formation is elevated in children with simple hypodontia. Arch Oral Biol 2011; 56:687-94. [DOI: 10.1016/j.archoralbio.2010.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 11/23/2010] [Accepted: 12/01/2010] [Indexed: 11/22/2022]
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16
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Fleckenstein M, Maumenee IH. Unilateral Isolated Microphthalmia Inherited as an Autosomal Recessive Trait. Ophthalmic Genet 2009; 26:163-8. [PMID: 16352476 DOI: 10.1080/13816810500468672] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To report a family with unilateral isolated microphthalmia showing an autosomal recessive pattern of inheritance. CASE REPORT We report a family in which three out of four children, one male and monozygotic female twins, were born with unilateral isolated microphthalmia to healthy consanguineous parents. One twin additionally had a horseshoe kidney. Rare cases of familial isolated microphthalmia/anophthalmia have been previously described. This is the first report of a family with autosomal recessive isolated microphthalmia occurring unilaterally in all affected individuals. It remains unknown how this inherited genetic disease results in unilateral manifestation. CONCLUSION Mirror imaging of this condition in the monozygotic twins may help elucidate the underlying mechanism. The constellation of features in this family may contribute to solve remaining questions of research into symmetry and asymmetry.
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Affiliation(s)
- Monika Fleckenstein
- The Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland 21287, USA.
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17
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Goto T, Nemoto T, Okuma T, Kobayashi H, Funata N. Mirror-image solitary bone cyst of the humerus in a pair of mirror-image monozygotic twins. Arch Orthop Trauma Surg 2008; 128:1403-6. [PMID: 18175134 DOI: 10.1007/s00402-007-0542-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Indexed: 11/28/2022]
Abstract
Mirror-image solitary bone cysts (SBCs) of the humerus in a pair of mirror-image monozygotic twins are presented. One twin was right-handed and had SBC at the left humerus. The other twin was left-handed and had SBC at the right humerus. The directions of the whirl of hair on their heads were opposite with each other. These findings strongly suggest cytogenetic factors in the aetiology or pathogenesis of SBC.
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Affiliation(s)
- Takahiro Goto
- Department of Orthopaedic Surgery and Musculoskeletal Oncology, Tokyo Metropolitan Komagome Hospital, 3-18-22 Hon-Komagome, Bunkyo-ku, Tokyo 113-8677, Japan.
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18
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Morokuma J, Blackiston D, Levin M. KCNQ1 and KCNE1 K+ channel components are involved in early left-right patterning in Xenopus laevis embryos. Cell Physiol Biochem 2008; 21:357-72. [PMID: 18453744 PMCID: PMC3632048 DOI: 10.1159/000129628] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2008] [Indexed: 01/12/2023] Open
Abstract
Several ion transporters have been implicated in left-right (LR) patterning. Here, we characterize a new component of the early bioelectrical circuit: the potassium channel KCNQ1 and its accessory subunit KCNE1. Having cloned the native Xenopus versions of both genes, we show that both are asymmetrically localized as maternal proteins during the first few cleavages of frog embryo development in a process dependent on microtubule and actin organization. Molecular loss-of-function using dominant negative constructs demonstrates that both gene products are required for normal LR asymmetry. We propose a model whereby these channels provide an exit path for K(+) ions brought in by the H(+),K(+)-ATPase. This physiological module thus allows the obligate but electroneutral H(+),K(+)-ATPase to generate an asymmetric voltage gradient on the left and right sides. Our data reveal a new, bioelectrical component of the mechanisms patterning a large-scale axis in vertebrate embryogenesis.
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Affiliation(s)
- Junji Morokuma
- Center for Regenerative and Developmental Biology, Forsyth Institute, Developmental Biology Department, Harvard School of Dental Medicine, Boston, MA 02115, USA
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19
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Aknin C, Allart JF, Rouland JF. Kératocône unilatéral en miroir chez des jumeaux monozygotes. J Fr Ophtalmol 2007; 30:899-902. [DOI: 10.1016/s0181-5512(07)74025-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Cohen-Levy J, Kamoun-Goldrat AS, Simon Y, Lautrou A. [Twins and the heritability of dentofacial phenotype]. Orthod Fr 2007; 78:69-77. [PMID: 17571534 DOI: 10.1051/orthodfr:2007004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
In orthodontics and dentofacial orthopaedics, where genetic and environmental factors interpenetrate from the early stages of development, the clinician tries to determine how mechanics could influence patient's growth pattern. Comparing monozygotic and dizygotic twins, in their similarities and their differences, gives some answers... but raises some questions too. In this article, we gather some clinical studies and case reports, on diagnosis and treatment aspects of malocclusions.
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Affiliation(s)
- Julia Cohen-Levy
- Faculté de chirurgie dentaire, Université Paris VII, 5 rue GaranciBre, 75006 Paris, France.
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21
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Cohen-Levy J, Berdal A. [Twins: a response to the question of genetic/environmental influence on development?]. Orthod Fr 2007; 78:63-7. [PMID: 17571533 DOI: 10.1051/orthodfr:2007002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
This article presents recent data about human twinning and explains how twin studies can bring precious informations about craniofacial growth. These natural experiences of growth phenomenon can give clues about genetic/environment interactions during development.
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Affiliation(s)
- Julia Cohen-Levy
- Faculté de chirurgie dentaire Université Paris VII, 5 rue GaranciBre, 75006 Paris, France.
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22
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Levin M. Is the early left-right axis like a plant, a kidney, or a neuron? The integration of physiological signals in embryonic asymmetry. ACTA ACUST UNITED AC 2006; 78:191-223. [PMID: 17061264 DOI: 10.1002/bdrc.20078] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Embryonic morphogenesis occurs along three orthogonal axes. While the patterning of the anterior-posterior and dorsal-ventral axes has been increasingly well-characterized, the left-right (LR) axis has only relatively recently begun to be understood at the molecular level. The mechanisms that ensure invariant LR asymmetry of the heart, viscera, and brain involve fundamental aspects of cell biology, biophysics, and evolutionary biology, and are important not only for basic science but also for the biomedicine of a wide range of birth defects and human genetic syndromes. The LR axis links biomolecular chirality to embryonic development and ultimately to behavior and cognition, revealing feedback loops and conserved functional modules occurring as widely as plants and mammals. This review focuses on the unique and fascinating physiological aspects of LR patterning in a number of vertebrate and invertebrate species, discusses several profound mechanistic analogies between biological regulation in diverse systems (specifically proposing a nonciliary parallel between kidney cells and the LR axis based on subcellular regulation of ion transporter targeting), highlights the possible importance of early, highly-conserved intracellular events that are magnified to embryo-wide scales, and lays out the most important open questions about the function, evolutionary origin, and conservation of mechanisms underlying embryonic asymmetry.
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Affiliation(s)
- Michael Levin
- Forsyth Center for Regenerative and Developmental Biology, The Forsyth Institute, and the Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts 02115, USA.
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23
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Dirani M, Chamberlain M, Garoufalis P, Chen CY, Guymer RH, Baird PN. Mirror-image congenital esotropia in monozygotic twins. J Pediatr Ophthalmol Strabismus 2006; 43:170-1. [PMID: 16761639 DOI: 10.3928/01913913-20060301-06] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Monozygotic twins had mirror-image congenital esotropia and discordant refractive errors. One had right congenital esotropia surgically corrected during childhood, and the other had left congenital esotropia surgically corrected at 3 and 6 years old.
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Affiliation(s)
- Mohamed Dirani
- Centre for Eye Research Australia, University of Melbourne, Australia
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24
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Levin M. Left-right asymmetry in embryonic development: a comprehensive review. Mech Dev 2005; 122:3-25. [PMID: 15582774 DOI: 10.1016/j.mod.2004.08.006] [Citation(s) in RCA: 329] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2004] [Revised: 08/22/2004] [Accepted: 08/23/2004] [Indexed: 12/17/2022]
Abstract
Embryonic morphogenesis occurs along three orthogonal axes. While the patterning of the anterior-posterior and dorsal-ventral axes has been increasingly well characterized, the left-right (LR) axis has only recently begun to be understood at the molecular level. The mechanisms which ensure invariant LR asymmetry of the heart, viscera, and brain represent a thread connecting biomolecular chirality to human cognition, along the way involving fundamental aspects of cell biology, biophysics, and evolutionary biology. An understanding of LR asymmetry is important not only for basic science, but also for the biomedicine of a wide range of birth defects and human genetic syndromes. This review summarizes the current knowledge regarding LR patterning in a number of vertebrate and invertebrate species, discusses several poorly understood but important phenomena, and highlights some important open questions about the evolutionary origin and conservation of mechanisms underlying embryonic asymmetry.
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Affiliation(s)
- Michael Levin
- Cytokine Biology Department, The Forsyth Institute, Boston, MA 02115, USA.
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25
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Abstract
Twinning has fascinated human beings over the centuries. New technologies and large study groups have led to improved documentation of frequency and complications in twin pregnancies and long-term outcomes. Artificial reproductive technologies have led to a pronounced rise in numbers of dizygotic and monozygotic twins. Although spontaneous dizygotic twinning is clearly associated with increased concentration of follicle-stimulating hormone and ovulation of more than one egg, causes of monozygotic twinning remain illusive. Twin studies are used increasingly to study complex traits and disorders: however, caution is suggested, since twins might not be representative of a typical singleton pregnancy. Monozygotic twinning seems to represent an anomaly in itself, with an increased number of spontaneous abortions and structural congenital anomalies. Both monozygotic and dizygotic twins have growth rates that slow at 30 weeks in utero and might be programmed both developmentally and biochemically earlier in pregnancy to have different responses at birth and after birth compared with singletons.
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Affiliation(s)
- Judith G Hall
- Department of Paediatrics, 4480 Oak Street, Room 2D19, British Columbia's Children's Hospital, BC, V6H 3V4, Vancouver, Canada.
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26
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Derbent M, Saygili A, Yilmaz Z, Kervancioğlu M, Balci S, Tokel K. Co-occurrence of chromosome 22q11.2 microdeletion and trisomy 21 mosaicism. AMERICAN JOURNAL OF MEDICAL GENETICS 2002; 112:99-102. [PMID: 12239730 DOI: 10.1002/ajmg.10545] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This report describes a patient who had some phenotypic features of Down syndrome (DS) as well as severe conotruncal cardiac anomalies, including pulmonary atresia with ventricular septal defect (tetralogy of Fallot with pulmonary atresia), confluent pulmonary arteries, a large left-sided ductus arteriosus, left aortic arch, aberrant right subclavian artery, and secundum atrial septal defect. Cytogenetic and fluorescence in situ hybridization (FISH) analysis was carried out on peripheral blood lymphocytes and skin fibroblasts using probes specific for the chromosomal loci 21q22.13 to 21q22.2 and locus 22q11.2. This revealed 47,XX+21/46,XX mosaicism at a rate of 15:85 and the micro-deletion 22q11.2 (del22q11.2). Some patients'congenital cardiac anomalies are atypical for the type of mosaicism or aneuploidy. The case suggests that association of del22q11.2 should be considered in patients with chromosomal mosaicism or aneuploidy who also have particular conotruncal cardiac defects.
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Affiliation(s)
- Murat Derbent
- Department of Pediatrics, Baskent University Faculty of Medicine, Ankara, Turkey.
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27
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Morini F, Ilari M, Casati A, Piserà A, Oriolo L, Cozzi DA. Posterior urethral valves and mirror image anomalies in monozygotic twins. AMERICAN JOURNAL OF MEDICAL GENETICS 2002; 111:210-2. [PMID: 12210353 DOI: 10.1002/ajmg.10563] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Monozygotic (MZ) twins with both posterior urethral valves (PUV) and additional mirror image malformations are described. This association suggests that an early embryonic event may lead to MZ twinning, PUV, and mirror image anomalies.
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Affiliation(s)
- Francesco Morini
- Pediatric Surgery Unit, Policlinico Umberto I, University of Rome La Sapienza, Rome, Italy
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28
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Noone PG, Bali D, Carson JL, Sannuti A, Gipson CL, Ostrowski LE, Bromberg PA, Boucher RC, Knowles MR. Discordant organ laterality in monozygotic twins with primary ciliary dyskinesia. AMERICAN JOURNAL OF MEDICAL GENETICS 1999; 82:155-60. [PMID: 9934981 DOI: 10.1002/(sici)1096-8628(19990115)82:2<155::aid-ajmg11>3.0.co;2-t] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Primary ciliary dyskinesia (PCD) is a genetic disease characterized by abnormal ciliary structure and function, impaired mucociliary clearance, and chronic middle ear, sinus, and lung disease. PCD is associated with situs inversus in approximately 50% of the patients. One proposed explanation for this relationship is that normal ciliary function plays a role in normal organ orientation, whereas organ orientation in PCD is a random event because of dysfunctional cilia in early embryonic development. Another hypothesis for the association between PCD and situs inversus is that mutated genes in PCD not only cause defective cilia, but are also linked to the control of organ laterality, such that abnormalities in this molecular pathway result in random left-right asymmetry. We report on a set of monozygotic twin women with PCD. In both patients, deficiency of the inner dynein arms was noted on ciliary ultrastructural analysis, associated with a clinical syndrome of bronchiectasis, chronic sinusitis, and middle ear disease. One of the twins has situs solitus, the other has situs inversus totalis. DNA analysis confirmed that the twins are monozygotic. This is consistent with the hypothesis that situs inversus occurring in patients with primary ciliary dyskinesia is a random but "complete" event in the fetal development of patients with PCD.
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Affiliation(s)
- P G Noone
- Department of Medicine, University of North Carolina at Chapel Hill, 27599-7249, USA.
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29
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Kindelan JD, Rysiecki G, Childs WP. Hypodontia: genotype or environment? A case report of monozygotic twins. BRITISH JOURNAL OF ORTHODONTICS 1998; 25:175-8. [PMID: 9800013 DOI: 10.1093/ortho/25.3.175] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
A case report is presented of monozygotic twins with variable expression of hypodontia. DNA fingerprinting was used to confirm monozygosity, and this evidence supports the theory that genetic coding is not the sole controlling factor in tooth agenesis. It is suggested that DNA fingerprinting should be considered the gold standard for determination of monozygosity.
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Affiliation(s)
- J D Kindelan
- Orthodontic Department, Leeds Dental Institute, UK
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30
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Abstract
In the past, twins have been studied to determine the genetic contribution to various disease processes. Recent work, however, suggests that monozygotic (MZ) twins are not truly identical. Many genetic forms of discordance have been described within MZ twin pairs and may even play a role in causing MZ twinning. Intra-uterine environmental differences in the allocation of the number of cells and in the placental vascular supply to each twin, as well as stochastic development events, may lead to major discordance at birth between the twins of a MZ pair.
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Affiliation(s)
- J G Hall
- Department of Pediatrica, University of British Columbia, British Columbia Children's Hospital, Vancouver, Canada. j
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