%0 Journal Article %A M J Seller %T Recurrence risks for neural tube defects in a genetic counseling clinic population. %D 1981 %R 10.1136/jmg.18.4.245 %J Journal of Medical Genetics %P 245-248 %V 18 %N 4 %X The recurrence of neural tube defects (NTD) in the sib following the index case of all patients who consulted the South-East Thames Regional Health Authority Genetics Centre in the period 1972 to mid-1979 was calculated. A total of 1037 consecutive patients was studied, of whom 958 (93%) were traced. The overall recurrence was 3.44% (1 in 29). However, if the index case was the first affected child in the family, the recurrence in the next sib was 3.15% (1 in 32), and if it was the second affected child, the recurrence was 11.76% (1 in 9). These figures give an indication of the actual recurrence among the 'selected' population who consult a genetic advice centre, and are somewhat, but not significantly, different from figures for the general NTD population, which have been derived from studies of whole families. %U https://jmg.bmj.com/content/jmedgenet/18/4/245.full.pdf