A recently published case study highlights the link between tetralogy of Fallot and Alagille syndrome (ALGS) in a male infant. 

“Although pulmonary stenosis is the most common heart defect within Alagille syndrome, tetralogy of Fallot with hypoplasia of the pulmonary branches may also be one of the clinical manifestations,” the authors said.

The child in the study was diagnosed with tetralogy of Fallot using echocardiography on day 3 of life after a systolic murmur was detected over the precordium. At 1 month of age, infundibular and valvular stenosis of the pulmonary artery was observed on ultrasound, verifying tetralogy of Fallot. Later analysis revealed elevated levels of liver transaminases, especially GGT enzymes.

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Due to the presence of tetralogy of Fallot and elevated liver transaminases, a spinal x-ray was performed, revealing skeletal system abnormalities in the thoracic 6 and 8 vertebrae (butterfly vertebrae). Ophthalmological examination showed posterior embryotoxon in both eyes. Genetic testing of the patient confirmed ALGS through heterozygous mutation in the JAG1 gene.

Read more on ALGS diagnosis

At 4 months of age, the infant underwent an invasive cardiac procedure to the pulmonary artery branches.

“The initial part of the right branch was 5 mm, followed by a fully hypoplastic right branch (3 mm) with middle segment stenosis up to 2 mm; the left branch [was] even more hypoplastic, entirely 2.2 mm with 2 mm segments,” the authors said.

Based on these findings, an aortic-pulmonary anastomosis was performed using a modified Blalock Taussig (mBT) compound.

Cardiac catheterization at a later hospitalization showed that hypoplastic pulmonary branches were still present with a narrow mBT joint. Dilatation of the pulmonary valve using a balloon was then performed to try and increase pulmonary blood flow.

The infant in the study was his mother’s first pregnancy which was controlled using regular methods. He appeared healthy at birth with only mild neonatal jaundice.


Herceg S, Dilber D, Šarić D, et al. 192 Alagille syndrome in infant with fallot tetralogy. Arch Dis Child. 2021;106:A81-A82. doi:10.1136/archdischild-2021-europaediatrics.192