News > A ‘parasitic unborn twin’ found in a one-year-old’s brain; what causes this?

A ‘parasitic unborn twin’ found in a one-year-old’s brain; what causes this?

Doctors in China’s Shanghai removed an “unborn twin” from the brain of a one-year-old girl, according to a study published in Neurology, a peer-reviewed journal. It was found to be the child’s twin after genome sequencing. Such cases arise from unseparated blastocysts –balls of cells that form during the early stages of pregnancy. According to the study, “The conjoined parts develop into the forebrain of host fetus and envelop the other embryo during neural plate folding.”