Neural tube defects: Heterogeneity and homogeneity

摘要: Detailed investigations were made on 150 fetuses with neural tube defects (NTD). After eliminating those recognised causes, the rest found to consist of both isolated NTD and other developmental abnormalities. On evaluation reproductive history, type frequencies in pregnancies before conception, sex involved, no demonstrable difference between these two types was found. Secondly, additional abnormalities, a significant clustering rather than uniform distribution throughout different demonstrated. As whole, major abnormalities predominantly cases total craniorachischisis upper thoracic spina bifida, less often anencephaly thoraco-lumbar never lumbo-sacral bifida. Thus it appears that there is not random concurrence but definite pattern. We suggest this implies connection abnormality arise due mechanical induction by particular specific disturbance its surrounding tissues. The most important associated disruption development at neurulation more far reaching latter former.