In 2014 they met with brothers and sisters brother-in-law, born in Australia, and have a very unusual connection. They are the twins they've ever met.
Since twins have received a mixture of DNA, but the genes received from their mother are equal to 100 percent. It is not only known in another case, but this pair was first detected before they were born.
"She showed the positioning of the amniotic bag that showed the ultrasound of the mother six weeks with a single placenta and two bags," says Nicholas Fisk, fictional medicine expert, four years ago while he was taking care of the young family based on the Royal Brisbane and Women's Hospital.
"However, in the 14 weeks, the ultrasounds were twin men and women, the twins were not the same".
Usually, the twins are made up of two pairs. It is not identical to the "dizjogotic" result of the two oboes given through a sperm.
Then they are the same, or "monozygous", where a single fertilized fat is distributed completely to different individuals before the program of growth and fetal development is anticipated.
Until 2007, the third "sesquizygotic" The theoretical idea of the category was. Then twins born in the United States were a random find.
These two children had a cellular mix, some with X chromosome and others with Y chromosome. If a child is not born intersexual, it is possible that we should not be any more secretive.
Also, while Australian twin twins are not physiologically present as intersex, they both have a series of cells with pairs of pairs of chromosome XX or XY.
Estimates of credit cardholders in amniotic on the earth also showed that each mother's DNA was equal to 100 percent and only 78% of father's DNA was matched.
One possible explanation for this series of single genome individuals is that it was possible to copy the mother's bread earlier in order to fertilize both sperm before, but they did not completely separate them.
There is another possibility, accompanied by specialists who study newer cases.
"It's likely that the mother's egg was fertilized at the same time by two of her father's sperm," says Fisk.
Like a friend labeled on a first date, an additional gene selection would lead to spell detection, and any newly embryonic embryos would normally not expect.
"However [Australian] Two sesicidal specimens, the fertilized egg, have divided three chromosomes into two parts, creating twins, "says Queensland University of Technology, Australian Medical Michael Gabbett.
For example, with a few examples, it is difficult to find out more detailed explanations or if twin sets are developed in a little way.
Likewise, it is difficult for twins to be the same as not to think, sharing the same selection of their mother's DNA.
Twin twins' global database research suggests that others are still very rare examples.
"We questioned at the beginning that other cases were poorly classified or not, 968 twin brothers and their parents analyzed genetic data," says Fisk.
"However, we have not found these data in the other two videos, or the twin ones, the twins in the main general analyzes."
It excludes rare cases such as the ordinary model of the victims' chemistry, at least for the time being.
The advances in the genetic study and medical data base would eventually bring about twin identical twins and perhaps better understand the fertilization process.
In the meantime, these twin sets can be legally claimed as two.
This study was published New England Journal of Medicine.