Yes. TOF can be caused by environmental factors. These include-

1. Diabetes in mother- This increases the chance of tetralogy of Fallot (TOF) three times.

2. Retinoic acids- If taken during the first trimester, there is increased chance of tetralogy of Fallot (TOF) along with nervous system and facial anomalies.

3. Phenylketonuria in the mother- tetralogy of Fallot (TOF) is especially likely to occur if the mother did not control intake of phenylalanine during pregnancy.

4. Trimethadione or paramethadione treatment during pregnancy.