3X Genetics is a Worcester, Massachusetts genetic diagnostics company founded in 2021 by Kevin Donahue after a seven-year diagnostic journey in his own family. It develops targeted long-read tests for repeat expansion disorders (REDs) -- genetic conditions such as Myotonic Dystrophy Type 1 that conventional sequencing struggles to resolve. Its patent-pending 3X-TGT platform measures targeted sequences directly without amplification, using AI-driven assay design plus validation to deliver faster, more precise and lower-cost tests from a saliva sample. The company runs a CLIA-certified laboratory in Manchester, New Hampshire and has raised roughly $3.16M toward a $4M seed round.