Recurrence rates in sibships and concordance rates in twins for anencephaly.
It is suggested that concordance rates in twins for anencephaly are higher than can be explained by the high recurrence rates within sibships, and the hypothesized higher rate of anencephaly in MZ pairs. The evidence is stronger in the case of same-sexed pairs, but points in the same direction for opposite-sexed pairs.
D000757:Anencephaly / Q000235:genetics*; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D011247:Pregnancy; D011336:Probability; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic