1. Embryology and Genetic Laboratory, Faculty of Health Sciences, Marien Ngouabi University, Brazzaville, Congo
2. Department of Clinical Sciences, Institute of Research on Health Sciences, Brazzaville, Congo
3. Centre de Génétique de l'Université de Kinshasa, DR Congo
4. Service de Génétique Humaine, Sart Tilman, Avenue de l'Hôpital 13, 4000, Liège, Belgium
5. Gastro-Enterology and Internal Medicine Service, CHU Brazzaville, Congo