During its short existence, the placenta is the workhorse of an organ.
That's because the fetus that grows inside depends entirely on the placenta, which performs a confusing array of functions (which provides oxygen, nutrition and more) later split up into the liver, kidneys, intestines and lungs.
Given the centrality of the human placental placenta, relatively little is known, scientists say, and a new study published on Monday in Nature Medicine has shown that the placenta plays a different, more surprising role : Your health is at risk for the development of schizophrenia, especially among those who already have a higher genetic risk for the disorder, according to Johns Hopkins University researchers.
Up to 70 percent of a person's risk for schizophrenia is based on genes, according to the National Institutes of Health. Www.cosmetic-business.com//showarti…p?art_id=575 Whether these genes are "on" or left unspoken depends in part on complications during pregnancy, the new study concludes. Englisch: www.cosmetic-business.com/en/showar…p?art_id=744.
The research team collected genetic tests from more than 2,800 adults around the world, USA, Europe and Asia. Of these participants, 2,038 were diagnosed with schizophrenia. And researchers looked at how their mothers' pregnancy went for all participants, researchers said.
This led to the key finding: For people whose genes pose a risk for schizophrenia, the child was at least five times more likely to suffer from this disease after a difficult or complicated pregnancy, researchers found
. No fewer than 20 percent of all pregnancies involve complications, Scientific American reports ̵
Once scientists linked pregnancy complications and placental stress to schizophrenia, they analyzed gene expression in placental tissue, including those who had complications such as pre-eclampsia or intrauterine growth restriction. What they found was "a conspicuous and consistent switching of the schizophrenia genes" in these placentas. As more of these schizophrenic risk genes became active, increasing the risk of developing the disease, researchers found more inflammation and other symptoms of stress.
"For the first time, we have found an explanation for the link between early complications, genetic risk and their effects on mental illness, and everything converges on the placenta," said Daniel R. Weinberger, senior researcher of the study of the Lieber Institute for Brain Development University, in a statement  Other scientists agreed that the study is an important step to understand how much of the disease is genetic and how much is environmental.
"This should be an eye-opening study, especially for anyone who believes the disease risk is genetic," said Janine LaSalle, a genetics researcher at the University of California at Davis, Stat. "Genes do not exist in a lock box, away from everything else that happens to you."
The researchers also said the study could provide clues as to why men develop not only schizophrenia up to four times more frequently, but also other disorders such as dyslexia, autism and Tourette's syndrome. The researchers discovered that the schizophrenia-linked genes that were activated during severe pregnancies were much more common in male placentas than female placentas.
Researchers said the findings were important because they could help doctors develop new treatments and therapies and "ultimately reduce the incidence of neurodevelopmental disorders."