Structural variant detection across sequencing technologies

Structural variants (SVs) are a major source of genomic diversity, yet their discovery remains challenging due to repetitive genomic contexts, alignment ambiguity and the trade-off between sequencing cost and read length. Here we introduce HitSV, which implements repetitiveness- and signature-density-aware breakpoint recognition coupled with precise haplotype-resolved local assembly, thereby enabling base-resolution SV reconstruction and genotyping in various sequencing technologies. On the HG002 benchmark, HitSV achieved 15-72% (long read), 10-36% (short read) and 12% (hybrid sequencing), respectively, higher genotype F1 scores than state-of-the-art SV callers. Applied to the 1KGP phase 4 cohort, HitSV expanded the SV callset by 31.5%, substantially reshaping allele-frequency landscapes. In a large Chinese long-read cohort, HitSV uncovered tandem-repeat-mobile-element composite arrays as a prevalent, multi-allelic class of complex SVs, highlighting composite repeat architectures as an important and previously underrecognized contributor to human structural variation.