Suzanne de Bruijn

196 Chapter 4 ( Table S6 ). In addition, breakpoint sequences revealed several DNA signatures that are indicative of distinct underlying mechanisms. For some SVs (e.g. NL-SV1), microhomology (2-5bp) was identified at the breakpoints, whereas longer stretches of homology (>100bp) were identified for breakpoints of UK-SV6 and UK-SV7. In these cases, (micro)homology-mediated repair is the likely mechanism giving rise to the SV. For other breakpoints (e.g. UK-SV1), small insertions and deletions were observed at breakpoint junctions, suggesting non-homologous end joining events ( Table S8 , Figure S4 ). In all SVs, there is a high content of repetitive elements, suggesting these play a role in both repair mechanisms.