ESPE Abstracts

Subclavian artery disruption sequence explains the development and association of Poland, Klippel-Feil, and Moebius anomalies with the hypothesis of vascular etiology. Herein, the coupling of Klippel-Feil-Poland-Moebius Syndromes and the diagnostic process in a patient who presented to our outpatient clinic with breast asymmetry will be discussed. At the age of 11 years and 10 months, the patient presented with breast asymmetry (smaller left breast-hypotelia). The patient's medical history revealed that her parents were cousins, and she was being followed up with the diagnoses of operated polydactyly on the left hand, patent ductus arteriosus closed with a coil, operated inguinal hernia, duplicated collecting systems in the right kidney. On physical examination, the right breast was compatible with stage V and the left breast was compatible with stage III. The rim of the right mouth was higher than the opposite side, and the patient had a short neck and left torticollis. Chromosome analysis was 46, XX. No pathogenic variant was detected in the whole exome sequencing analysis. After re-evaluation, considering the hypothesis of vascular etiology (subclavian artery disruption sequence), it was thought that the hypotelia finding was due to unilateral pectoralis major muscle hypoplasia as in the Poland sequence and thumb anomalies, short neck, low hairline and limitation in neck movements and C6-C7 cervical fusion and segmentation anomaly were due to Klippel Feil anomaly. The patient had an association of Klippel-Feil, Poland, and Moebius anomalies. When all these findings of the patient were considered together, it was suggested that these findings could be explained by a disruption sequence (subclavian artery disruption sequence) based on the hypothesis of vascular etiology instead of a monogenic cause or malformation syndrome. The breast asymmetry could be explained by unilateral pectoralis major muscle hypoplasia as in the Poland sequence; polydactyly, patent ductus arteriosus, urinary system anomalies, short neck, low hairline, restricted neck movements and C6-C7 cervical fusion and segmentation anomaly could be explained by Klippel-Feil anomaly; and facial asymmetry (higher right anguli oris) due to possible unilateral 7th cranial nerve palsy can be explained by the Moebius sequence. The association of these findings can be explained by the vascular hypothesis, interruption of early embryonic blood flow in the subclavian arteries, vertebral arteries, and/or their branches, and disruption of embryologic development in these regions.