Extensive analysis of mosaicism in a case of Turner syndrome: The experience of 287 cytogenetic laboratories

Jonathan P. Park, Arthur R. Brothman, Merlin G. Butler, Linda D. Cooley, Gordon W. Dewald, Kurt F. Lundquist, Catherine G. Palmer, Shivanand R. Patil, Kathleen W. Rao, Irene A. Saikevych, Nancy R. Schneider, Gail H. Vance

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

Objective. - To assemble and interpret karyotype data provided as part of the College of American Pathologists/American College of Medical Genetics Cytogenetics Proficiency Testing Program. Data Sources, Extraction, and Synthesis. - The Cytogenetics Resource Committee requested data on all cells analyzed in a 1994 whole-blood specimen challenge. In that study, 287 participating laboratories analyzed a total of 14 297 cells derived from a sample drawn from an adult donor with Turner syndrome. This individual had previously been found to have mosaicism, including cell lines with X structural anomalies along with monosomy X, making this an excellent challenge for a multicenter cytogenetic survey. Results and Conclusions. - Analysis of the data from this extensive study revealed mosaicism of up to 10 different sex chromosome complements involving the X chromosome with and without a small ring X or a derivative X chromosome. In the routine cytogenetic analysis performed by the participating laboratories, cell lines observed, in decreasing order of prevalence, included 45,X (n = 8357 cells), 46,X,r(X) (n = 3597), 46,X,der(X)t(X;X) (n = 2237), 46,XX (n = 93), 47,X,r(X),r(X) (n = 5), 47,X,der (X)t(X;X),der(X)t(X;X) (n = 3), 47,XX,r(X) (n = 2), and one observation each of 47,XX,der(X)t(X;X), 47,X,der(X)t (X;X),r(X), and 47,XXX. Our molecular cytogenetic data, as well as detailed analysis of G-banded chromosomes, suggest the nomenclature for these 2 abnormal X chromosomes as r(X)(p11.3q21.3) and der(X)t(X;X)(p11.3;q21.3), and we discuss models for the concomitant formation of these 2 entities. Both the degree of analysis and the extensive mosaicism that was discovered in this study are exceptional, and similar reported cases as well as possible mechanisms for the observed X chromosome instability are reviewed.

Original languageEnglish (US)
Pages (from-to)381-385
Number of pages5
JournalArchives of Pathology and Laboratory Medicine
Volume123
Issue number5
StatePublished - May 18 1999

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ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Medical Laboratory Technology

Cite this

Park, J. P., Brothman, A. R., Butler, M. G., Cooley, L. D., Dewald, G. W., Lundquist, K. F., Palmer, C. G., Patil, S. R., Rao, K. W., Saikevych, I. A., Schneider, N. R., & Vance, G. H. (1999). Extensive analysis of mosaicism in a case of Turner syndrome: The experience of 287 cytogenetic laboratories. Archives of Pathology and Laboratory Medicine, 123(5), 381-385.