At ASHG, pilot data from GeneDx using Illumina’s Constellation mapped‑read technology showed improved detection of variants in genomic regions historically challenging for short reads, including large repeat expansions and complex structural variants in genes such as DMPK and SMN1. GeneDx presented early access results from a 160‑sample pilot comparing Constellation to orthogonal methods including long‑read sequencing and arrays. Illumina and GeneDx said Constellation preserves short‑read throughput while delivering longer‑range mapping information, potentially reducing reliance on costly long‑read assays for some diagnostics. For readers: mapped reads combine short‑read economies with informative read placement to resolve repeats and structural complexity — a workflow advance that could change diagnostic pipelines if validated across larger cohorts.