We report a 13-week-old female fetus with early onset fetal akinesia deformation sequence (FADS) and hydranencephaly. In a previous pregnancy, the same ultrasonographic findings were noted at 13 weeks. Fetopathological examination of both female fetuses confirmed FADS with severe arthogryposis, multiple pterygia, and muscular hypoplasia. Neuropathological examination showed massive cystic dilatation of the cerebral ventricles (hydranencephaly) with calcification of the basal ganglion and brain stem and a proliferative vasculopathy throughout the central nervous system. The findings in the two female siblings document the earliest echographic diagnosis of hydranencephaly, Fowler type, and this observation further supports autosomal recessive inheritance of this distinct type of hydranencephaly. © 2002 Wiley-Liss, Inc.