Open AccessGenomic Characterization of Chromosomal Insertions: Insights into the Mechanisms Underlying Chromothripsis
Author(s) -
Takema Kato,
Yuya Ouchi,
Hidehito Inagaki,
Yoshio Makita,
Seiji Mizuno,
Mitsuharu Kajita,
Tsutomu Ikeda,
Kazuhiro Takeuchi,
Hiroki Kurahashi
Publication year - 2017
Publication title -
cytogenetic and genome research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.571
H-Index - 88
ISSN - 1424-8581
DOI - 10.1159/000481586
Subject(s) - chromothripsis , biology , genetics , breakpoint , chromosomal rearrangement , chromosome , genome , trisomy , karyotype , gene , dna , genome instability , dna damage
Chromosomal insertions are rare structural rearrangements, and the molecular mechanisms underlying their origin are unknown. In this study, we used whole genome sequencing to analyze breakpoints and junction sequences in 4 patients with chromosomal insertions. Our analysis revealed that none of the 4 cases involved a simple insertion mediated by a 3-chromosomal breakage and rejoining events. The inserted fragments consisted of multiple pieces derived from a localized genomic region, which were shuffled and rejoined in a disorderly fashion with variable copy number alterations. The junctions were blunt ended or with short microhomologies or short microinsertions, suggesting the involvement of nonhomologous end-joining. In one case, analysis of the parental origin of the chromosomes using nucleotide variations within the insertion revealed that maternal chromosomal segments were inserted into the paternal chromosome. This patient also carried both maternal alleles, suggesting the presence of zygotic trisomy. These data indicate that chromosomal shattering may occur in association with trisomy rescue in the early postzygotic stage.