X microchromosome with additional chromosome anomalies found in Ullrich-Turner syndrome

✍ Scribed by Wydner, Karen L. ;Li, Mengrong ;Singer-Granick, Carol ;Sciorra, Leonard J. ;Krueger, Leslie J.

• Book ID: 102703540
• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 712 KB
• Volume: 56
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/ajmg.1320560205

✦ Synopsis

Abstract

Using standard cytogenetic methods coupled with molecular techniques, the following karyotype mos 45,X/46,XXq+/46,X+mar (X)/47,XXq+,+mar(X), was identified in a patient with Ullrich‐Turner syndrome (UTS). High‐resolution banding (n = 650) of the metaphase chromosomes yielded a breakpoint at q28 on the Xq+ rearranged chromosome. FISH was used to determine the presence of Y‐containing DNA in the Xq+ and the mar(X) chromosomes. The following molecular probes were used: DYZ1, DYZ3, and spectrum orange WCP Y. The lack of specific hybridization of these probes was interpreted as a low risk of gonadoblastoma in this patient. Using X‐chromosome‐ and centromerespecific probes, FISH demonstrated the presence of hybridizing material on both rearranged chromosomes, the Xq+ and mar(X). Finally, we determined that the mar(X) and Xq+ chromosomes contained telomeres in the absence of any interstitial telomeric hybridizing material. A micro‐X chromosome is present in this UTS patient. Delineation of events leading toward the mechanisms responsible for the multiple DNA rearrangements required to generate the micro‐X and Xq+ chromosomes awaits future studies. © 1995 Wiley‐Liss, Inc.