Frequent translocations occur between low copy repeats on chromosome 22q11.2 (LCR22s) and telomeric bands of partner chromosomes
| Autor: | Catherine D. Kashork, Lisa G. Shaffer, Lorraine Potocki, Melanie Babcock, Elizabeth Spiteri, Keiko Wakui, Swarna Gogineni, Bernice E. Morrow, Debbie A. Lewis, Kisa M. Williams, Alan L. Shanske, Takashi Sasaki, Venkat Pulijaal, Nobuyoshi Shimizu, Shinsei Minoshima |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Somatic cell
Chromosomes Human Pair 22 Molecular Sequence Data Chromosomal translocation Biology Hybrid Cells Genome Translocation Genetic Cell Line Genetics Humans Molecular Biology Genetics (clinical) In Situ Hybridization Fluorescence Base Sequence Breakpoint Palindrome Chromosome Chromosome Mapping Chromosome Breakage General Medicine Low copy repeats Sequence Analysis DNA Telomere Molecular biology Tandem Repeat Sequences Homologous recombination |
| Zdroj: | Human molecular genetics. 12(15) |
| ISSN: | 0964-6906 |
| Popis: | The chromosome 22q11.2 region is susceptible to rearrangements, mediated by low copy repeats (LCR22s). Deletions and duplications are mediated by homologous recombination events between LCR22s. The recurrent balanced constitutional translocation t(11;22)(q23;q11) breakpoint occurs in an LCR22 and is mediated by double strand breaks in AT-rich palindromes on both chromosomes 11 and 22. Recently, two cases of a t(17;22)(q11;q11) were reported, mediated by a similar mechanism (21). Except for these constitutional translocations, the molecular basis for non-recurrent, reciprocal 22q11.2 translocations is not known. To determine whether there are specific mechanisms that could mediate translocations, we analyzed cell lines derived from 14 different individuals by genotyping and FISH mapping. Somatic cell hybrid analysis was carried out for four cell lines. In five cell lines, the translocation breakpoints occurred in the same LCR22 as for the t(11;22) translocation, suggesting that similar molecular mechanisms are responsible. An additional three occurred in other LCR22s, and six were in non-LCR22 regions, mostly in the proximal half of the 22q11.2 region. The translocation breakpoints on the partner chromosomes were all located in the telomeric bands, proximal to the most telomeric unique sequence probe, in eight cell lines and distal to those loci in six. Therefore, several of the breakpoints were found to occur in the vicinity of highly dynamic regions of the genome, 22q11.2 and telomeric bands. We hypothesize that these regions are more susceptible to breakage and repair, resulting in translocations. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|