Dept of Medical Genetics, The Chaim Sheba Medical Center, Tel-Hashomer, Sackler School of Medicine, Tel Aviv University, Israel.
Most cases are sporadic and of unknown cause.
There are no environmental teratogens known to cause this malformation in humans, but in animals the condition can be induced by veratrum alkaloids and radiation. Ingestion of salicylates in pregnancy has also been reported in relation to holoprosencephaly. Extracranial malformations include renal cysts and dysplasia, omphalocele, cardiovascular malformations, clubfoot, myelomeningocele and intestinal abnormalities. The early detection of fetal brain malformations is now possible 1-3 . The purposes of this communication are to describe the intracranial findings consistent with alobar holoprosencephaly and to emphasize the role of high frequency transvaginal ultrasonography in establishing early diagnosis at 10 weeks of gestation.