This is a great article explaining Grair’s heart issue. He has Tetralogy of Fallot (TOF) with Absent Pulmonary Valve (APV) syndrome.
http://www.emedicine.com/ped/topic2538.htm

The article explains that TOF “is the most common cause of cyanotic heart disease and may occur at a rate of 1-3 cases per 1000 live births.” Grair has this. The article also goes on to explain that “TOF with absent pulmonary valve is rare, and approximately 3% of patients with TOF have the absent pulmonary valve syndrome.” Grair falls in this category as well.

Surgery will be performed this afternoon, and as we know more we’ll add more updates.