New diagnostic and genomic mapping studies revealed clinically relevant structural variants (SVs) that standard sequencing often misses. Optical genome mapping detected additional genetic variants in nearly 20% of acute leukemia patients at a Canadian center, while a separate pan‑cancer analysis from St. Jude and the National Cancer Institute released the largest pediatric structural‑variant dataset to date in Cancer Cell. Both efforts highlight how large‑scale SV discovery can change diagnoses, refine risk stratification and uncover targetable alterations. Authors urge integrating orthogonal genome technologies into diagnostic pipelines for hematologic and pediatric cancers, noting that SVs—rearrangements, large insertions and deletions—are poorly captured by short‑read methods but can drive oncogenesis and therapeutic choice.