Subclavian artery supply disruption sequence: Hypothesis of a vascular etiology for Poland, Klippel‐Feil, and Möbius anomalies

A hypothesis is presented to explain the pathogenesis of the Poland, Klippel-Feil, and Möbius anomalies, isolated absence of the pectoralis major with breast hypoplasia, isolated terminal transverse limb defects, and the Sprengel anomaly. We propose that these conditions are the result of an interruption of the early embryonic blood supply in the subclavian arteries, the vertebral arteries and/or their branches, and hypothesize that the occlusions occur at specific locations in these vessels during or around the sixth week of embryologic development and produce predictable patterns of defects. The term subclavian artery supply disruption sequence (SASDS) is suggested for the group of birth defects represented by the above conditions. Possible causes for interruption of embryonic blood supply are discussed.