Discrepant unbalanced structural chromosome aberrations between placental and fetal tissue, both involving the short arm of chromosome 4, were found in two human fetuses affected with Wolf-Hirschhorn syndrome. In the first instance, placental chromosome examination revealed a del(4) (p14), whereas fetal fibroblast chromosomes showed an unbalanced der(4)t(4;13)(p14;q11) translocation. In the second instance, placental karyotyping revealed a 4p+ chromosome, while amniocytes showed a submicroscopic deletion at 4p16.3. Since confirmation of structural aberrations from placental tissue is mostly not sought if the phenotype of the fetus is abnor- mal, discrepancies between karyotypes obtained from placental tissue and amniocytes or fetal tissues might be more frequent than the rare reports published so far would suggest. It is unclear whether the simple deletion or the more complex rearrangement is the primary aberration from which the other derived. Structural chromosome aberrations often have a much more complex mechanism of formation than the end product would suggest, and secondary rearrangements of a given aberration in the zygote are more frequent than expected.   

1.
Eiben B, Leipoldt M, Schübbe I, Ulbrich R, Hansmann I: Prenatal detection of 4p– in fetal cells not present in chorionic villi. Clin Genet 33:49–52 (1988).
2.
Farra C, Giudicelli B, Pellissier MC, Philip N, Piquet C: Fetoplacental chromosomal discrepancy. Prenat Diagn 20:190–193 (2000).
3.
Kalousek DK, Barrett I J, McGillivray BC: Placental mosaicism and intrauterine survival of trisomies 13 and 18. Am J hum Genet 44:338–343 (1989).
4.
Kotzot D: Abnormal phenotypes in uniparental disomy (UPD): fundamental aspects and a critical review with bibliography of UPD other than 15. Am J med Genet 82:265–274 (1999).
5.
Kotzot D, Martinez MJ, Bagci G, Basaran S, Baumer A, Binkert F, Brecevic L, Castellan C, Chrzanowska K, Dutly F, Gutkowska A, Berker Karaüzüm S, Krajewska-Walasek M, Lüleci G, Miny P, Riegel M, Schuffenhauer S, Seidel H, Schinzel A: Parental origin and mechanisms of formation of cytogenetically recognizable de novo direct and inverted duplications. J med Genet 37:281–286 (2000).
6.
Ledbetter DH, Zachary JM, Simpson JL, et al: Cytogenetic results from the U.S. collaborative study on CVS. Prenat Diagn 12:317–345 (1992).
7.
Minelii A, Floridia G, Rossi E, Clementi M, Tenconi R, Camurri L, Bernardi F, Hoeller H, Previde Re C, Maraschio P, Wood S, Zuffardi O, Danesino C: D8S7 is consistently deleted in inverted duplications of the short arm of chromosome 8 (inv dup 8p). Hum Genet 92:391–396 (1993).
8.
Pittalis MC, Dalprà L, Torricelli F, Rizzo N, Nocera G, Cariati E, Santarini L, Tilibetti MG, Agosti S, Bovicelli L, Forabosco A: The predictive value of cytogenetic diagnosis after CVS based on 4860 cases with both direct and culture methods. Prenat Diagn 14:267–278 (1994).
9.
Porter S, Wilson E, Tyler X, Warren R, French-Constant C, Pearson J: A case of discordant related abnormal karyotypes from chorionic villi and amniocytes. Prenat Diagn 19:887–890 (1999).
10.
Smeets E, Petit P, Fryns JP: Submicroscopic terminal 4p16 deletion in a female child with milder Wolf-Hirschhorn syndrome phenotype and 46,XX,del (4p16)/46,XX,t(4;16)(p16.3;pter)mat mosaicism. Genet Counsel 9:87–88 (1998).
11.
Verjaal M, Leschot NJ, Wolf H, Treffers PE: Karyotypic differences between cells from placenta and other fetal tissues. Prenat Diagn 7:343–348 (1987).
12.
Wolstenholme J: Cytogenetic analysis of chorionic villi for prenatal diagnosis: an ACC collaborative study of U.K. data. Prenat Diagn 14:363–379 (1994).
© 2001 S. Karger AG, Basel
2001
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.