22q.11: a Risk Factor for Left Pulmonary Artery Hypoplasia in Congenital Heart Disease

Individuals with 22q11 deletion syndrome have a mutation in the TBX1 gene. This is associated with reduced left pulmonary artery/right pulmonary artery ratio in animal models and in humans with structurally normal hearts.

A retrospective analysis was undertaken of patients who underwent surgical repair of Tetralogy of Fallot, truncus arteriosus, and interrupted aortic arch between 01/2007 and 12/2022. The left pulmonary artery/right pulmonary artery ratio on initial and most recent echocardiogram and initial and subsequent intervention on the left pulmonary artery were compared between patients with and without 22q11 deletion.

There were 134 included patients; 19 patients had the deletion (22q11 positive), and 115 patients did not have the deletion (22q11 negative). Tetralogy of Fallot was present in 8/19 and 101/115 patients, truncus arteriosus in 7/19 and 7/115 patients, and interrupted aortic arch in 4/19 and 7/115 patients. Patients who were 22q11 positive had a reduced left pulmonary artery/right pulmonary artery ratio on both the initial echocardiogram [0.88 (interquartile range 0.71, 0.97) versus 1.02 (interquartile range 0.92, 1.12); p < 0.001] and most recent echocardiogram [0.66 (interquartile range 0.62, 0.91) versus 1.01 (interquartile range 0.89, 1.16); p < 0.001] and were more likely to have intervention on the left pulmonary artery at their initial surgery (36% versus 8.7%; p = 0.003).

Patients who were 22q11 positive trended towards reduced left pulmonary artery/right pulmonary artery ratios and need for early surgical intervention on the left pulmonary artery in comparison to patients without 22q11 deletion negative patients.