Nonsyndromal anencephaly: possible autosomal recessive variant.

The recurrence of anencephaly in families has been explained on a multifactorial basis. We present two unrelated families with three sibships of several nonsyndromal anencephalics including two pairs of concordantly affected like-sex twins. A rare autosomal recessive variant is proposed and inheritance is discussed in view of parental consanguinity among the two affected sibships in one family.