Described herein, among other things, is a method of sequencing, comprising: concatenating a plurality of fragments of genomic DNA to produce concatenated DNA; sequencing the concatenated DNA to produce a plurality of sequence reads, wherein at least some of the sequence reads comprise: at least the sequence of the 3′ and/or 5′ ends of a fragment that corresponds to the locus of interest and sequence of one or both of the fragments that flank the fragment in the concatenated DNA; and grouping the sequence reads that corresponds to the locus of interest using, for each of the grouped sequence reads: the 3′ and/or 5′ end sequences; and/or the flanking sequence.