A review of the embryological development and associated developmental abnormalities of the sternum in the light of a rare palaeopathological case of sternal clefting.

A sternal cleft or bifid sternum is a rare anterior chest wall abnormality. Although several cases have been reported in clinical literature, very little reference has been made to this anomaly in palaeopathological texts. This paper presents a case of superior sternal clefting observed in a middle-aged female with concurrent Paget's disease and congenital hyperkyphosis excavated from a 19th century Dutch psychiatric asylum cemetery in Bloemendaal, The Netherlands. The embryological development of the sternum and associated developmental abnormalities are reviewed and a differential diagnosis is performed on the suite of observed skeletal anomalies. Goltz syndrome, congenital hypothyroidism, disruption of the Hoxb-4 gene, acute excessive maternal alcohol consumption during pregnancy, Coffin-Lowry syndrome and PHACES syndrome were considered as possible causative agents, with the latter two conditions determined to be the most likely. The psychiatric asylum context, from which the individual came, supports the differential diagnosis as neurological abnormalities are common in these two syndromes. This article demonstrates that the integration of embryology, modern clinical literature and palaeopathological principles is vital in the interpretation of developmental anomalies from an archaeological context.