P657: Real-world evaluation of ExpansionHunter for detecting STR expansions in whole-exome sequencing data: Insights from a clinical diagnostic setting

ExpansionHunter is a bioinformatics tool designed to detect and analyze repeat expansions in short tandem repeats (STRs) using short-read sequencing data. It identifies reads that span, flank, or are fully contained within each repeat in BAM/CRAM files and maps them to the reference genome to estimate the size of the repeat expansion at each locus. STR expansions are implicated in a variety of genetic disorders, including Huntington’s disease and several spinocerebellar ataxias. ExpansionHunter has demonstrated considerable sensitivity and specificity in detecting STR expansions from PCR-free genome sequencing data.