Aneuploidy: A condition in which a person has one or a few chromosomes above or below the normal chromosome number. For example, three copies of chromosome21, which is characteristic of Down syndrome, is a form of aneuploidy.
A localized widening (dilatation) of an artery, a vein, or the heart. At the point of an aneurysm, there is typically a bulge. The wall of the blood vessel or organ is weakened and may rupture.
- Aneurysm, abdominal
Aneurysm, abdominal: An aneurysm situated within the abdomen (belly). An aneurysm is a localized widening (dilatation) of an artery, vein, or the heart. At the area of an aneurysm, there is typically a bulge and the wall is weakened and may rupture. The word “aneurysm” comes from the Greek “aneurysma” meaning “a widening.” See: Aneurysm, […]
- Aneurysm, berry
Aneurysm, berry: A small aneurysm that looks like a berry and classically occurs at the point at which a cerebral artery departs from the circular artery (the circle of Willis) at the base of the brain. Berry aneurysms frequently rupture and bleed.
- Aneurysm, brain
Aneurysm, brain: An aneurysm of a blood vessel in the brain, usually due to a defect in the vessel at birth or from high blood pressure. Rupture of the aneurysm causes a sudden severe headache, often with nausea, vomiting, decreased consciousness, and can be life threatening.
- Aneurysm, dissecting
Aneurysm, dissecting: An aneurysm in which the wall of an artery rips (dissects) longitudinally. This occurs because bleeding into the weakened wall splits the wall. Dissecting aneurysms tend to affect the thoracic aorta. They are a particular danger in Marfan syndrome.