Background: Truncus arteriosus communis (TAC) is a congenital heart defect in which the physiologic arterial common trunk was not divided into aorta and pulmonary artery trunk.

Objectives: In this paper, we report on three observed cases from which we looked for (in conjunction with literature review) the different causes of TAC many of which have genetic origins.

Methods: We collected three clinical files of fetuses having a TAC. Two of them were examinated after a medical termination of pregnancy motivated by severe cardiopathy. The malformation had been diagnosed based on different techniques: echocardiography, skeletal radiography, arteriography, fetal autopsy, karyotype and fluorescence in situ hybridization (FISH).

Results: Imaging and fetopathological examination revealed the presence of TAC type 3 and 4 in the Van Praaghs classification. FISH analysis showed a 22q11.2 deletion in one fetus in favour of Digeorge syndrome. The karyotype analysis performed in two cases was normal.

Conclusion: Truncus arteriosus is a rare pathology caused by numerous etiologies from which many of them have genetic origin. This malformation can be diagnosed early during prenatal period. Postmortem fetopathological examination allows a better diagnosis approach and eventually a genetic counseling in recurrent cases such as case of consanguinity.