Next-Generation Sequencing Strategies Enable Routine Detection of Balanced Chromosome Rearrangements for Clinical Diagnostics and Genetic Research

• Published in: American journal of human genetics Vol. 88; no. 4; pp. 469 - 481
• Main Authors: Talkowski, Michael E., Ernst, Carl, Heilbut, Adrian, Chiang, Colby, Hanscom, Carrie, Lindgren, Amelia, Kirby, Andrew, Liu, Shangtao, Muddukrishna, Bhavana, Ohsumi, Toshiro K., Shen, Yiping, Borowsky, Mark, Daly, Mark J., Morton, Cynthia C., Gusella, James F.
• Format: Journal Article
• Language: English
• Published: Cambridge, MA Elsevier Inc 08.04.2011; Cell Press; Elsevier
• Subjects: Biological and medical sciences; Cells; Chromosome Inversion; Chromosomes; Chromosomes, Human - genetics; Computational Biology; Deoxyribonucleic acid; Diagnostic tests; DNA; DNA Barcoding, Taxonomic; DNA Breaks; Female; Fundamental and applied biological sciences. Psychology; Gene Library; Gene Rearrangement; General aspects. Genetic counseling; Genetics; Genetics of eukaryotes. Biological and molecular evolution; Genome, Human; Genome-Wide Association Study; Humans; Interspersed Repetitive Sequences; Karyotyping; Male; Medical genetics; Medical sciences; Molecular and cellular biology; Oligonucleotide Array Sequence Analysis; Polymorphism; Sequence Analysis, DNA - methods; Translocation, Genetic; Human; Nucleotide sequence; Chromosome; Genetics; Strategy; Diagnosis; Detection; Sequencing
• ISSN: 0002-9297; 1537-6605; 1537-6605
• DOI: 10.1016/j.ajhg.2011.03.013

The contribution of balanced chromosomal rearrangements to complex disorders remains unclear because they are not detected routinely by genome-wide microarrays and clinical localization is imprecise. Failure to consider these events bypasses a potentially powerful complement to single nucleotide polymorphism and copy-number association approaches to complex disorders, where much of the heritability remains unexplained. To capitalize on this genetic resource, we have applied optimized sequencing and analysis strategies to test whether these potentially high-impact variants can be mapped at reasonable cost and throughput. By using a whole-genome multiplexing strategy, rearrangement breakpoints could be delineated at a fraction of the cost of standard sequencing. For rearrangements already mapped regionally by karyotyping and fluorescence in situ hybridization, a targeted approach enabled capture and sequencing of multiple breakpoints simultaneously. Importantly, this strategy permitted capture and unique alignment of up to 97% of repeat-masked sequences in the targeted regions. Genome-wide analyses estimate that only 3.7% of bases should be routinely omitted from genomic DNA capture experiments. Illustrating the power of these approaches, the rearrangement breakpoints were rapidly defined to base pair resolution and revealed unexpected sequence complexity, such as co-occurrence of inversion and translocation as an underlying feature of karyotypically balanced alterations. These findings have implications ranging from genome annotation to de novo assemblies and could enable sequencing screens for structural variations at a cost comparable to that of microarrays in standard clinical practice.