Systems and method for identifying long deletions can obtain sequencing information for a plurality of amplicons in and around a potential region from a nucleic acid sample. The sequencing information can include a plurality of reads that can be mapped to a reference sequence. Using information, such as where reads map to a reference sequence and relative abundance of reads for the amplicons, structural variants can be identified and a determination can be made if the nucleic acid sample is homozygous or heterozygous for the structural variant.