A pair of 4-year-old younger brothers in Brisbane, Australia, was recognized as the second-and-a-half identical twin in the world. It is also the first half-family twin to be found in the mother. Their mother did it in 2014. At the time of the birth check, the Australian genetic research team had noticed a rare embryogenesis process.
According to the formation process, twins can be divided into identical twins, fraternal twins and semi-isolated twins. Semi-identical twins are quite rare.
In 2014, a 28-year-old Australian woman underwent an ultrasound examination at 6 weeks of pregnancy. The doctor found that the embryo shared the placenta like a twin, but after 14 weeks the doctor found that the twins were a man and a woman, apparently non-identical twins. After learning about the medical professor of Queensland University of Technology, Gabate, he immediately started genetic research with the team.
Although the pair of twins in Australia did not show hermaphrodites, they experienced considerable twists and turns. The girl developed a blood clot shortly before birth, and her arm was amputated when she was around. Then at the age of three, the girl’s ovaries are removed because it is not fully formed, which may increase the risk of certain cancers.
Semi-identical twins are still quite rare. Reviewed nearly 1,000 pairs of genetic data considered to be fraternal twins,but found no cases of semi-identical twins.