Neural tube defects: sex ratios and recurrence risk

ABSTRACT

This study included fifty families having sixty-four patients with neural tube detects [NTD]. Fourteen families had two affected members and thirty-six ones had only one affected member. The common types of NTD as well as the relation between the position of the NTD lesions and sex were studied. Also, the sex ratio and the concordance for NTD lesion and sex were estimated. The recurrence rate in sibs of the probands was also calculated. Anencephaly was found in 60.9% of cases, followed by encephalocele in 18.8%, then meningomyelocele in 12.5% and finally the spina bifida in 7.8%. The overall male/female ratio was 1.06. A male preponderance was observed in the anencephalic patients, while female excess was found in the encephalocelic group. In lower spina bifida, all cases were males. Concordance of sex was found in 75% of the upper lesions and in 100% of the lower ones. The recurrence rate was high in the upper lesions. Periconceptional vitamins and folic acid as well as proper prenatal diagnosis by both anatomical and biochemical evaluations of the fetus have reduced the recurrence of the NTD