The World`s Rarest Twins

When Hollywood film makers cast Arnold Schwarzenegger and Danny De Vito as unlikely twins in the 1998 move Twins, it was considered to be a sales gimmick. But for some parents of twins, the unexpected arrival of children who are nothing alike is no gimmick. Just part of life.

Perhaps the most infamous set of odd twins were Arnold Schwarzenegger and Danny De Vito in the movie Twins. But  two completely different twins is not just something that Hollywood film makers conjured up. For some it`s just they way things worked.

Black and White twins

In 2005 Kylie Hodgson gave birth to twin girls Remee and Kian. Kylie and her partner Remi are of mixed race themselves, both have white mothers and black fathers. This type of birth is more common when the mother is impregnated by two separate fathers, but experts say that the odds of this type of birth are about a million in one.

Twins Fathered by Two Different Men

When Wilma and Willem Stuart married in 1984, they assumed that having children would be the next big step. The couple tried unsuccessfully for six years before turning to invitro fertilization. Wilma learned in April 1993 that she was pregnant, and soon after found out that she was carrying twins. The boys were delivered by emergency C section in Dec of 1993.

It was three days before the Stuarts saw their twin boys side by side and noticed the differences in the way the boys looked. One was small and had light skinned, while the other was dark and much larger. It was at this point in time that  the Stuarts began to ask questions, but were told by hospital staff that liver problems might be the reason for darker skin and that it would pass. But by the time the boys were six months old, the Stuarts began to question the paternity of their sons.

When the boys were just over a year old, DNA testing proved that little Koen was indeed fathered by someone other than Willem Stuart. The hospital where the invitro was performed has called the situation "a deeply regrettable mistake" and  speculation is that a piece of  equipment called a pipette ( like a large eyedropper), had been used twice, causing another man’s sperm to be mixed with Willem`s.

Symmetric  Conjoined Twins

Abby and Brittany  Hensel were born in Minnesota on March 7 1990. The girls have separate spines  and separate half sacrums resulting in a broad pelvis. They each control and sense their corresponding arm and leg. (a third, central arm was amputated when they were babies) Each twin controls one side of the body. By coordinating both sides of the body, the girls are able not only to walk, but to participate in in activities like sports, playing the piano and even driving a car. The twins attend college at Bethel University in Minnesota.

Superfetation

Brother and sister Harriet, left, and Thomas were born to the same mother just one minute apart, but they are not twins. They were actually conceived three weeks apart. Superfetation is the formation of a fetus when there is already a fetus in the uterus. Although Superfetation is common in some animal species it is rare in humans.