OEIS complex (omphalocele-exstrophy-imperforate anus-spinal defects) in monozygotic twins: a case report and literature review

Abstract

OEIS complex (omphalocele-exstrophy-imperforate anus-spinal defects) in monozygotic twins: a case report and literature review Y.Q. Xu1, X. L. Chen2, S. Zhao2, P. W. Chen2, X. M. Yin1, S. Y. Xiong1, Z. Ding3, F. Xiong4, X. H. Yang2 1Department of Ultrasound, Baoan Central Hospital of Shenzhen/The 5th affiliated hospital of Shenzhen University Health Science Center, 60 Xixiang Leyuan Street, Baoan district, Shenzhen, 518102 (P.R. China) 2Department of Ultrasound, Hubei Women and Children’s Hospital, 745 Wuluo Road, Wuhan, Hubei 430070 (P.R. China) 3The Institute of Metabolic Diseases, Baoan Central Hospital of Shenzhen/The 5th affiliated hospital of Shenzhen University Health Science Center, 60 Xixiang Leyuan Street, Baoan district, Shenzhen, 518102 (P.R. China) 4Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, Guangdong (P.R. China) Summary The omphalocele-exstrophy-imperforate anus-spinal defects (OEIS) complex represents severe midline abdominal and pelvic defects of unknown etiology. This complex is rare, affecting 1 in 200,000 to 400,000 pregnancies and is extremely rare in twin or triplet gestations. Here, we report the OEIS complex in a spontaneous monozygotic twin pregnancy and previously reported OEIS complex in twin or triplet pregnancy are reviewed. Spontaneous pregnancy and unremarkable family history, but concordance of monozygotic twins for the defect may support the theory that early malformation complexes, e.g., OEIS, may be related to errors in monozygotic splitting in early blastogenesis. Key words: Omphalocele-exstrophy-imperforate anus-spinal defects (OEIS); Twin pregnancy.