Classification of read pairs.

The relationship between paired-end reads and structural variants according to a partition based on their separation distances and orientations. The meanings of symbols: F: forward read; R: reverse read; d: separation distance; μ: insert size (mean); σ: standard deviation; x: a user-defined parameter; N: normal; D: deletion; I: insertion; Iv: inversion; Ta: tandem duplication; Tra: intrachromosomal translocation; Tre: interchromosomal translocation; C: other complex structure event.