2016 Apr;37(4):385-95. doi: 10.1002/humu.22953. Epub 2016 Feb 4.

Author information

1
Applied Human Molecular Genetics, Kennedy Center, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Glostrup, 2600, Denmark.
2
Department of Cellular and Molecular Medicine (ICMM), Faculty of Health Science, University of Copenhagen, Copenhagen, N. 2200, Denmark.
3
Department of Cellular and Molecular Medicine, Faculty of Health Science, University of Copenhagen, Copenhagen, N. 2200, Denmark.
4
Center for Genomic Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, O. 2100, Denmark.
5
Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, 84112.

Abstract

Chromothripsis (CTH) is a phenomenon where multiple localized double-stranded DNA breaks result in complex genomic rearrangements. Although the DNA-repair mechanisms involved in CTH have been described, the mechanisms driving the localized "shattering" process remain unclear. High-throughput sequence analysis of a familial germline CTH revealed an inserted SVAE retrotransposon associated with a 110-kb deletion displaying hallmarks of L1-mediated retrotransposition. Our analysis suggests that the SVAE insertion did not occur prior to or after, but concurrent with the CTH event. We also observed L1-endonuclease potential target sites in other breakpoints. In addition, we found four Alu elements flanking the 110-kb deletion and associated with an inversion. We suggest that chromatin looping mediated by homologous Alu elements may have brought distal DNA regions into close proximity facilitating DNA cleavage by catalytically active L1-endonuclease. Our data provide the first evidence that active and inactive human retrotransposons can serve as endogenous mutagens driving CTH in the germline.

KEYWORDS:

Alu; L1; LINE-1; NAHR; SINE-VNTR-Alu; SVA; chromothripsis; nonallelic homologous recombination

PMID:
 
26929209
 
DOI:
 
10.1002/humu.22953
[Indexed for MEDLINE]