We report on 2 sibs with bilateral porencephaly, absence of the septum pellucidum, and pancerebellar hypoplasia including absence of the vermis. Situs inversus and tetralogy of Fallot was present in one, and an atrial septal defect in the other. This constellation of findings is discussed against the background of familial porencephalies and schizencephalies, familial cerebellar hypoplasias, and asplenia/polysplenia syndromes. It is concluded that the described constellation of findings constitutes a new entity of probably autosomal recessive inheritance.