Breakpoint mapping in a case of mosaicism with partial monosomy 9p23 --> pter and partial trisomy 1q41 --> qter suggests neo-telomere formation in stabilizing the deleted chromosome

Am J Med Genet A. 2006 Jan 1;140(1):82-7. doi: 10.1002/ajmg.a.31045.

Abstract

We report on a clinical and molecular cytogenetic study of a patient who presents a complex chromosomal rearrangement with two different cell lines. Using high-resolution GTG banding and fluorescence in situ hybridization (FISH) with several probes, including bacterial artificial chromosomes (BACs), the karyotype was defined as 46,XX,del(9)(p23)[54]/46,XX,der(9)t(1;9)(q41;p23)[46], indicating the presence of monosomy 9p23 in all cells and trisomy 1q41 in approximately 50% of the cells. The patient studied presents most of the manifestations of the 9p deletion and 1q duplication syndromes. The breakpoint was mapped at 9p23 with a loss of approximately 13.9-Mb of DNA. The duplicated segment consists of approximately 35 Mb from 1q41-qter region. We also suggest that a mechanism for telomere capture and interstitial telomeric sequences (ITs) is involved in a neo-telomere formation in one of the cell lines. This study highlights the importance of combining high-resolution chromosome and FISH with BACs in order to make genotype-phenotype correlations and to understand the mechanisms involved chromosomal aberrations.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • Chromosome Aberrations*
  • Chromosome Banding
  • Chromosome Breakage / genetics
  • Chromosome Deletion
  • Chromosomes, Human, Pair 1 / genetics*
  • Chromosomes, Human, Pair 9 / genetics*
  • Female
  • Humans
  • In Situ Hybridization, Fluorescence
  • Karyotyping
  • Models, Genetic
  • Monosomy
  • Mosaicism*
  • Telomere / genetics*
  • Translocation, Genetic
  • Trisomy