A neocentromere is a functional centromere that has arisen within a region not known to have a centromere. We present a case with a very rarely reported class II neocentromere formation in an aberrant chromosome 7. A 22-month-old male was referred because of dysmorphic features. Banding cytogenetics was performed, and a ring 7 and a supernumerary marker chromosome along with a normal chromosome 7 were found. In situ hybridization using a centromeric probe revealed 46 signals, of which 2 signals for chromosome 7 were observed, one on the normal and one on the ring chromosome. Further analysis using FISH revealed that the linear acentric fragment was part of the 7q region, which suggests that there could be a possible McClintock mechanism.

Alonso A, Hasson D, Cheung F, Warburton PE: A paucity of heterochromatin at functional human neocentromeres. Epigenetics Chromatin 3:6 (2010).
Amor DJ, Choo KH: Neocentromeres: role in human disease, evolution, and centromere study. Am J Hum Genet 71:695-714 (2002).
Blom E, Heyning FH, Kroes WG: A case of angioimmunoblastic T-cell non-Hodgkin lymphoma with a neocentric inv dup(1). Cancer Genet Cytogenet 202:38-42 (2010).
Burrack LS, Berman J: Neocentromeres and epigenetically inherited features of centromeres. Chromosome Res 20:607-619 (2012).
Choo KHA: The Centromere (Oxford University Press, Oxford 1997).
Ebrahim SA: Neocentromere formation in a stable rearranged chromosome 7 with class II pericentric interstitial deletion and the formation of ring chromosome 7. Poster presented at the annual ASHG meeting in Philadelphia, USA, November 11-15 (2008).
Klein E, Rocchi M, Ovens-Raeder A, Kosyakova N, Weise A, et al: Five novel locations of neocentromeres in human: 18q22.1, Xq27.1 approximately 27.2, acro p13, acro p12, and heterochromatin of unknown origin. Cytogenet Genome Res 136:163-166 (2012).
Koch J: Neocentromeres and alpha satellite: a proposed structural code for functional human centromere DNA. Hum Mol Genet 9:149-154 (2000).
Lamb AN, Estabrookes LL, Legator MS, Ramakrishnan R, Poole I, et al: Combinatorial 24 chromosome multicolor FISH for the identification of constitutional abnormalities: unbalanced translocations and analphoid marker chromosomes. Am J Hum Genet 63:A142 (1998).
Liehr T, Kosyakova N, Weise A, Ziegler M, Raabe-Meyer G: First case of a neocentromere formation in an otherwise normal chromosome 7. Cytogenet Genome Res 128:189-91 (2010).
Maraschio P, Tupler R, Rossi E, Barbierato L, Uccellatore F, Rocchi M, Zuffardi O, Fraccaro M: A novel mechanism for the origin of supernumerary marker chromosomes. Hum Genet 97:382-386 (1996).
Marshall OJ, Choo KH: Neocentromeres come of age. PLoS Genet 5:e1000370 (2009).
Marshall OJ, Chueh AC, Wong LH, Choo KH: Neocentromeres: new insights into centromere structure, disease development, and karyotype evolution. Am J Hum Genet 82:261-82 (2008).
O'Connor C: Chromosome segregation in mitosis: the role of centromeres. Nat Educ 1:28 (2008).
Rooney D: Human cytogenetics - The Practical Approach Series, p 512 (Oxford University Press, Oxford 2000).
Seabright M: A rapid banding technique for human chromosomes. Lancet 2:971-972 (1971).
Tyler-Smith C, Gimelli G, Giglio S, Floridia G, Pandya A, et al: Transmission of a fully functional human neocentromere through three generations. Am J Hum Genet 64:1440-1444 (1999).
Voullaire LE, Slater HR, Petrovic V, Choo KHA: A functional marker centromere with no detectable alpha-satellite, satellite III, or CENP-B protein: activation of a latent centromere? Am J Hum Genet 52:1153-1163 (1993).
Warburton PE: Chromosomal dynamics of human neocentromere formation. Chromosome Res 12:617-626 (2004).
Warburton PC, Barwell J, Splitt M, Maxwell D, Bint S, Ogilvie CM: Class II neocentromeres: a putative common neocentromere site in band 4q21.2. Eur J Hum Genet 11:749-753 (2003).
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.