[Risk of recurrence in major craniospinal malformations between 1976 and 2005]

Craniospinal malformations are among the commonest developmental disorders. Due to its incidence the knowledge of the risk of recurrence is very important not only for the geneticist but also for the married couples.

In the period between January 1st, 1976 and December 31st, 2005, among the 75320 documented cases at the Genetic Counselling Units of the Departments of Obstetrics and Gynecology of the University of Debrecen and Semmelweis University Budapest, consultations were requested due to previous craniospinal malformations in the patients' history in 3030 cases (4.2%). This paper contains the most important informations about these cases of craniospinal malformations. The greatest risk of non-central nervous system developmental anomalies was associated with holoprosencephaly.

In approximately two thirds of the cases (65.1%), the couples sought counselling because of malformation in a previous pregnancy. In these cases, the risk of recurrence was thought to be 5.2%, while in the case of two affected children this figure stood at 21.9%. When the risk of recurrence was analysed according to the various types, much lower figures (3.8%) were found for neural tube defects compared to other anomalies in this study.

Analysing the values for the risk of recurrence in five-year periods, neural tube defects (particularly anencephaly and spina bifida) showed detectable decrease, which could be attributed to a widening use of folic acid supplementation around about the time of conception and during pregnancy.