Triploidy

**Definition:** A disease caused by one additional set of chromosomes, for a total of 69 chromosomes. Triploidy can present with albuminuria, oedema, or hypertension in the mother. The fetus may present with microcephaly and a placenta that is enlarged and filled with cysts in the case of extra maternally inherited chromosomes, while extra paternally inherited chromosomes cause severe growth problems, an enlarged head, and a small placenta that does not have cysts. Non-mosaic triploidy is highly lethal, and is rarely observed in live births. Confirmation is through observation of an additional set of chromosomes by karyotyping.