Spina bifida and anencephaly: a problem in genetic–environmental interaction

Abstract

Anencephaly and spina bifida cystica, malformations of the central nervous system, are due to failure of closure of the neural tube. These malformations are a major cause of stillbirth, infant death and (in the case of spina bifida) of childhood morbidity in Britain today.Their aetiology is not known in detail. There are, however, indications from family studies and from the striking racial variation in their incidence (which is in part at least maintained after migration) that genetic factors are important in their causation. There is also evidence from maternal age and birth order effects, secular and seasonal variation, and social class effects that environmental factors also are important in their aetiology.