Cover image credited to AsiaWire
A baby born in China with an extremely rare deformity has undergone surgery to remove their third leg. Doctors revealed that the extra limb did not actually belong to the young child, called Xiao Fei, but that the third limb was a result of the very rare condition that is a combination of vanishing twins and conjoined twins. It often results in the two twins being merged partway through their development and can even result in a condition known as chimerism where the person has organs and limbs that come from two genetically separate individuals.
In this case, it resulted in Xiao Fei being born with a limb that belonged to his lost twin. It had no function and for this reason doctors sought to remove it. However, Xiao’s right leg was born with a deformed foot that was, essentially, a hand. As part of their corrective surgery doctors took the healthy foot from the middle leg and have swapped it with the hand that grew on his right leg.
Xiao Fei was also born with a number of conditions including an undescended testicle, an abdominal hernia, and congenital heart disease which surgeons say made the procedure significantly more complicated. Surgeons say that now Xiao Fei will lead a normal life given the success of the surgery. During the procedure doctors also corrected his undescended testicles. His father told reporters:
“I thank the doctors very much. I was so nervous sitting outside the surgery room, but now after I see my child, I'm not nervous any more.”
Chimerism can produce some bizarre situations. In 1950 Dutch athlete Foekje Dillema was disqualified after she refused a mandatory sex test; later tests revealed she had a Y-chromosome inherited from a parasitic twin. She was classified as a mosaic female.
Unbelievable! https://t.co/DdGeiRiu65— Metro (@MetroUK) 20 March 2018
In another case, Lydia Fairchild was denied access to her child after blood tests revealed she was not the child’s genetic mother. This was a bit of a surprise to Lydia since her daughter had come straight out of her uterus years before. However, her defence lawyer read about chimerism and proceeded to have Lydia tested. It was revealed that Lydia’s uterus had actually developed from her lost twin’s cells and so had a different genetic profile. Afterwards, scientists confirmed that her daughter was Lydia’s child by taking the blood sample from Lydia’s uterus and not her arm.