Polar twins
From Wikipedia, the free encyclopedia
Polar twins or Non-identical monozygotic twins are twins which split from the same zygote but are non-identical. Despite having identical genomes, they develop differently for various reasons.
Polar twins are said to occur when a single egg splits in two and the two halves are fertilized by two separate sperm. The part of the egg that splits off is referred to as the first polar body. This body will usually disintegrate. The result of the two bodies being separately fertilized is a set of twins who have half of their genes in common (from the mother) and the other half different (from the two different sperm). They share some features of identical twins and some features of fraternal twins and are sometimes referred to as half-identical twins.
Polar body twinning is only a theory as there are currently no DNA-based zygosity tests available to determine if twins are polar.
[edit] Similar conditions
This condition is similar yet not identical to that of Half Twins but is still often confused.
[edit] References
- Non-identical Monozygotic Twins (Developmental Biology Online)
- FAQ - Polar Twins (Proactive Genetics)
 |
This article is uncategorized. Please help improve this article by adding it to one or more categories, in addition to a stub category. (how?) Please remove this tag after categorizing, but not before. This article has been tagged since March 2007. |
 |
This developmental biology article is a stub. You can help Wikipedia by expanding it. |
