GeneDx piloted Illumina’s Constellation mapped‑read technology on NovaSeq X Plus instruments to detect variants that evade standard short‑read methods. The early access pilot, presented at ASHG, showed Constellation could identify complex structural variants, repeat expansions and difficult regions such as DMPK, SMN1 and NCF1 that often require orthogonal assays. The mapped‑read approach aims to deliver long‑range information from short‑read chemistry, reducing reliance on separate long‑read workflows. If validated at scale, the method could speed rare‑disease diagnostics and lower costs by enabling existing short‑read labs to capture previously inaccessible variant classes.