Katharina Schoner1, Roland Axt-Fliedner2, Rainer Bald3, Barbara Fritz4, Juergen Kohlhase5, Thomas Kohl6, Helga Rehder1,7. 1. Institute of Pathology, WG Fetal Pathology, University of Gießen and Marburg, Philipps University of Marburg, Marburg, Germany. 2. Department of Prenatal Medicine, University Hospital of Gießen and Marburg, Gießen, Germany. 3. Department of Gynecology and Obstetrics, Klinikum Leverkusen, Leverkusen, Germany. 4. Center of Human Genetics, University of Gießen and Marburg, Philipps University of Marburg, Marburg, Germany. 5. Praxis for Human Genetics - Center of Preimplantation Genetic Diagnosis, Freiburg, Germany. 6. German Center for Fetal Surgery & minimal-invasive Therapy, University Hospital of Gießen and Marburg, Gießen, Germany. 7. Institute of Medical Genetics, Medical University Vienna, Vienna, Austria.
Abstract
INTRODUCTION: The prevalence of neural tube defects worldwide is 1 - 2 per 1000 neonates. Neural tube defects result from a disturbance of neurulation in the 3rd or 4th week of development and thus represent the earliest manifestation of organ malformation. Neural tube defects (NTD) are classified into cranial dysraphism leading to anencephaly or meningoencephalocele and spinal dysraphism with or without meningomyelocele. In isolated form they have multifactorial causes, and the empirical risk of recurrence in Central Europe is 2%. As associated malformations they tend to occur sporadically, and in monogenic syndromes they follow Mendelian inheritance patterns with a high risk of recurrence. PATIENTS: Autopsies were performed on 68 fetuses following a prenatal diagnosis of NTD and induced abortion. RESULTS: The incidence of NTDs in our autopsied fetuses was 8% and 11% in fetuses with malformations. The percentage of fetuses with anencephaly, encephalocele or spina bifida was 24, 18, and 60%*, respectively. Analysis of the sex distribution showed a female preponderance in cranial dysraphisms but the sex distribution of spina bifida cases was equal. The extent and localization of NTDs varied, with lumbosacral cases clearly predominating. The proportion of isolated, associated and syndromic neural tube defects was 56, 23.5 and 20.6% respectively. In the majority of syndromes, the neural tube defect represented a not previously observed syndromic feature. CONCLUSION: The high proportion of NTDs with monogenic background underlines the importance of a syndrome oriented fetal pathology. At the very least it requires a thourough photographic and radiographic documentation of the fetal phenotype to enable the genetic counsellor to identify a syndromic disorder. This is necessary to determine the risk of recurrence, arrange confirming mutation analyses and offer targeted prenatal diagnosis in subsequent pregnancies.
INTRODUCTION: The prevalence of neural tube defects worldwide is 1 - 2 per 1000 neonates. Neural tube defects result from a disturbance of neurulation in the 3rd or 4th week of development and thus represent the earliest manifestation of organ malformation. Neural tube defects (NTD) are classified into cranial dysraphism leading to anencephaly or meningoencephalocele and spinal dysraphism with or without meningomyelocele. In isolated form they have multifactorial causes, and the empirical risk of recurrence in Central Europe is 2%. As associated malformations they tend to occur sporadically, and in monogenic syndromes they follow Mendelian inheritance patterns with a high risk of recurrence. PATIENTS: Autopsies were performed on 68 fetuses following a prenatal diagnosis of NTD and induced abortion. RESULTS: The incidence of NTDs in our autopsied fetuses was 8% and 11% in fetuses with malformations. The percentage of fetuses with anencephaly, encephalocele or spina bifida was 24, 18, and 60%*, respectively. Analysis of the sex distribution showed a female preponderance in cranial dysraphisms but the sex distribution of spina bifida cases was equal. The extent and localization of NTDs varied, with lumbosacral cases clearly predominating. The proportion of isolated, associated and syndromic neural tube defects was 56, 23.5 and 20.6% respectively. In the majority of syndromes, the neural tube defect represented a not previously observed syndromic feature. CONCLUSION: The high proportion of NTDs with monogenic background underlines the importance of a syndrome oriented fetal pathology. At the very least it requires a thourough photographic and radiographic documentation of the fetal phenotype to enable the genetic counsellor to identify a syndromic disorder. This is necessary to determine the risk of recurrence, arrange confirming mutation analyses and offer targeted prenatal diagnosis in subsequent pregnancies.
Authors: Elke Januschek; Andreas Röhrig; Sandra Kunze; Christian Fremerey; Bea Wiebe; Martina Messing-Jünger Journal: Childs Nerv Syst Date: 2016-04-16 Impact factor: 1.475