22q11.2 Deletion Syndrome Diagnosed 47 Years After Surgery for Tetralogy of Fallot

Abstract

A 51-year-old man presented with severe hydrocele testis, dyspnea on exertion, and systemic edema. He had a history of surgery for tetralogy of Fallot (TOF). On the second day of admission, he presented with severe nose bleeding followed by CO₂ narcosis. Blood gas analysis revealed an extremely low level of Ca²⁺. An echocardiogram revealed an excessively enlarged right ventricle and severe pulmonary valve regurgitation (PR). Hypocalcemia, history of TOF, and characteristic facial features suggested 22q11.2 deletion syndrome, which was confirmed by fluorescence in-situ hybridization (FISH) chromosome test. Open heart redo-surgery was performed for severe PR. The surgery revealed a severely hypoplastic pulmonary valve, which is characteristic of 22q11.2 deletion syndrome. 22q11.2 syndrome thus could be overlooked until age over 50 and therefore become critical.

Keywords: 22q11.2 deletion syndrome; digeorge syndrome; hypocalcemia; obstructive sleep apnea syndrome (osas); tetralogy of fallot.