We present two families with sib recurrence of a phenotype which was originally diagnosed as fetal brain disruption sequence (FBDS). In the first family from the Hindu population of Surinam, two brothers were affected. In the second family of Dutch descent a brother and sister were affected. Periodic ultrasonic sound examinations of brain development of the girl in the second family appeared normal until 26 weeks of gestation after which progressive destruction of her brain was seen. Recurrence of the FBDS in a family is noteworthy as it is usually considered a sporadic disorder. Suggested causes in the literature are viral infections or early vascular interruption of the fetal brain with subsequent massive destruction of cerebral neurons. In 1995 the first familial case of FBDS was described, indicating a genetic cause. Recently Kavaslar et al. [2000: Am J Hum Genet 66:1705–1709.] found a locus on chromosome 16 in a large inbred Anatolian family with a phenotype resembling FBDS. Our experience and the literature show that the cause of the phenotype “FBDS” is heterogeneous. In case of sib recurrence the term FBDS should be avoided since a disruption sequence indicates an exogenous and sporadic cause of the disorder. © 2004 Wiley-Liss, Inc.