title: Congenital hydranencephaly/porencephaly due to vascular disruption in monozygotic twins.
abstract: Monozygotic twinning has been associated with a variety of vascular disruptive defects including congenital hydranencephaly/porencephaly. Data involving 24 cases of congenital hydranencephaly/porencephaly associated with twinning are reported. In these cases, the finding of a preponderance of monozygotic twins and the common association of a deceased co-twin support the hypothesis of a vascular disruptive etiology. These defects are presumed to be secondary to embolic phenomena or thromboplastin release from the deceased co-twin to the survivor via the vascular interconnections of a conjoined monochorionic placenta. In all cases of hydranencephaly/porencephaly, a careful examination of the placenta and membranes for evidence of a deceased co-twin is warranted prior to providing recurrence risk counseling.
mesh_terms: D000757:Anencephaly / Q000209:etiology*; D001921:Brain / Q000002:abnormalities*; D004200:Diseases in Twins; D004211:Disseminated Intravascular Coagulation / Q000150:complications; D004617:Embolism / Q000150:complications; D005260:Female; D005313:Fetal Death / Q000150:complications; D006801:Humans; D006832:Hydranencephaly / Q000209:etiology*; D007231:Infant, Newborn; D008297:Male; D010920:Placenta / Q000098:blood supply; D011247:Pregnancy; D013925:Thromboplastin / Q000096:biosynthesis; D014427:Twins; D014430:Twins, Monozygotic
chemical_list: D013925:Thromboplastin