1. 1Department of Biochemical Sciences, Pomeranian Medical University, Szczecin, Poland.
2. 2Department of Pediatrics, Division of Pediatric Cardiology, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, the Netherlands.
3. 3Academic Centre for Congenital Heart Disease, Nijmegen, the Netherlands.
4. 4Department of Gastroenterology, Pomeranian Medical University, Szczecin, Poland.