title: Resolving genomic disorder-associated breakpoints within segmental DNA duplications using massively parallel sequencing.
abstract: The most common recurrent copy-number variants associated with autism, developmental delay and epilepsy are flanked by segmental duplications. Complete genetic characterization of these events is challenging because their breakpoints often occur within high-identity, copy-number polymorphic paralogous sequences that cannot be specifically assayed using hybridization-based methods. Here we provide a protocol for breakpoint resolution with sequence-level precision. Massively parallel sequencing is performed on libraries generated from haplotype-resolved chromosomes, genomic DNA or molecular inversion probe (MIP)-captured breakpoint-informative regions harboring paralog-distinguishing variants. Quantification of sequencing depth over informative sites enables breakpoint localization, typically within several kilobases to tens of kilobases. Depending on the approach used, the sequencing platform, and the accuracy and completeness of the reference genome sequence, this protocol takes from a few days to several months to complete. Once established for a specific genomic disorder, it is possible to process thousands of DNA samples within as little as 3-4 weeks.
authors.affiliation: Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington, USA.
authors.forename: Xander
authors.initials: X
authors.lastname: Nuttle
authors.affiliation: Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington, USA.
authors.forename: Andy
authors.initials: A
authors.lastname: Itsara
authors.affiliation: Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington, USA.
authors.forename: Jay
authors.initials: J
authors.lastname: Shendure
authors.affiliation: 1] Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington, USA. [2] Howard Hughes Medical Institute, University of Washington School of Medicine, Seattle, Washington, USA.
authors.forename: Evan E
authors.initials: EE
authors.lastname: Eichler
mesh_terms: D056905:Chromosome Breakpoints; D019295:Computational Biology / Q000379:methods; D016678:Genome / Q000235:genetics*; D015698:Genomic Library; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D056916:Segmental Duplications, Genomic / Q000235:genetics*