alpha-Thalassemia, though one of the most common genetic abnormalities in humans, is uncommon outside of tropical or subtropical regions of the world. The authors describe a family of northern European ancestry with a clinical presentation consistent with alpha-thalassemia-1, or deletion of both alpha globin genes on chromosome 16 in cis. Genomic mapping studies show that the deletion in this family spans 36.5-40 kbp and removes the entire alpha globin locus. This represents a novel deletion causing alpha-thalassemia-1, here termed "--RT." The 5' breakpoint is localized near the 5' breakpoints of previously described deletions in Thai and Filipino persons, consistent with this being an unstable region of chromosome 16.