: 100–101  Although males and females were initially believed to be affected equally, more recent studies have shown TOF affects males more than females. About 1 in 100 newborns is diagnosed with a congential heart defect, of which 10% are diagnosed with TOF. Genetically, it is most commonly associated with Down syndrome and DiGeorge syndrome. Down syndrome and other chromosomal disorders are known to occur alongside congential heart defects such as TOF. History
Tetralogy of Fallot was initially described in 1671 by the Danish researcher Niels Steensen. Also referenced as Nicolaus Steno in Latin, Stensen was a pioneer in anatomy and geology. His work made significant contributions to the field of cardiac anatomy and pathology, which led to the condition initially being titled Steno-Fallot tetralogy. A further description was published in 1888 by the French physician Étienne-Louis Arthur Fallot, after whom it was ultimately named. In 1924, Maude Elizabeth Seymour Abbott, a pediatric cardiologist from Montreal, Canada, named it tetralogy of Fallot.The short paper "Dissection of a Monstrous Foetus in Paris" in 1671 first described the conditions that would later together be known as TOF. In particular, it highlighted the unusual formation of arteries, the stenosing of the pulmonary artery, the absence of the ductus arteriosus, an overriding aorta, and fetal cardiac circulation where blood was redirected to the aorta from the pulmonary artery. Over a hundred years later in 1777, Dutch physician Eduard Sandifort reported what he referred to as "the blue boy" patient.
Reactions that begin sooner are typically more severe. Epidemiology
Acute hemolytic transfusion reaction is estimated to occur in 1 in 38,000 to 1 in 70,000 transfusions. An estimated 41% of ABO-incompatible transfusions result in AHTR. == References ==