Complex conotruncal cardiac anomalies consecutively in three siblings from a consanguineous family possibly associated with maternal hyperhomocysteinemia

Conotruncal defects represent an anatomically heterogeneous group of cardiac malformations affecting the outflow tract of the ventricles and the arterial pole of the heart. The exact etiology of congenital heart diseases is unknown.

A 31–year-old woman who had three offspring with complex conotruncal cardiac anomalies after consanguineous marriage was reported. The first child is still alive. However, the second affected child died at the age of 3 years. Fluorescence in situ hybridization studies of the siblings excluded CATCH₂₂ chromosomal abnormality. The maternal laboratory work-up was unremarkable except for low serum folic acid and cobalamin levels and high homocysteine levels. The woman received high dose pyridoxine, cobalamin and folate treatment preconceptionally, and she became pregnant. She delivered a healthy male infant without any abnormalities. Six months later, she became pregnant again without any preconceptional medications. When she was examined during the fourth pregnancy, unfortunately the fetus was found to have a restrictive ventricular septal defect, a right ventricle with two outflows and a right aortic arch. Her last pregnancy was terminated at 22 weeks. The 22-week-old female fetus was examined postmortem and the diagnosis of congenital heart disease was confirmed.

Cobalamin and folate administration may help to reduce the development of cardiac malformations.