Some children born with the genetic risk for schizophrenia, scientists say
NationalPost.com – Health
April 22, 2016. Amy Ellis Nutt, Washington Post
Schizophrenic patients rarely display symptoms of their mental illness before adulthood. In new research, scientists have found important evidence supporting the idea that a certain subset of those who develop the highly hereditary disease are genetically set on that path before birth.
“When a schizophrenic patient walks into a clinic at 18 [hearing voices], you’re seeing what’s already gone wrong,” said Kristen Brennand, one of the lead authors of the study published Thursday in the journal Cell Reports. “This shows us what goes wrong earlier in life, before symptoms ever develop.” < http://www.cell.com/cell-reports/fulltext/S2211-1247(16)30396-5 >
Tiny molecules of microRNAs that control hundreds of genes associated with schizophrenia are under-expressed during fetal development, according to the new study by an international team of researchers. One specific group of these cellular RNA fragments, known as miR-9, were highly under-expressed, making those fetuses particularly vulnerable to developing schizophrenia later in life.
The genes under miR-9’s control are important to the growth and maturation of neurons in the human fetal brain. Their under-expression, say the researchers, means certain brain circuits will likely not be wired correctly during prenatal development.
The team that conducted the research included biologists, neuroscientists, psychiatrists and mathematicians. It also involved a complex laboratory procedure only five years old.
Most molecular experiments in schizophrenia research are greatly limited because they must be conducted post-mortem, on brain tissue derived from deceased patients. The scientists involved in the new study overcame this problem by engineering fetal schizophrenic neurons.
First, they obtained skin samples from living schizophrenic patients, then they reprogrammed the skin cells into embryonic-like stem cells before finally coaxing them to develop into human brain cells. These reverse-engineered “schizophrenic neurons,” akin to fetal cells in the first or second trimester of a woman’s pregnancy, became the basis for the study.
The importance of the discovery was underscored by the fact that these “perturbed” miR-9 levels, which appear responsible for deficiencies in fetal brain development, have not been detected in the brains of schizophrenic patients after death.
“If the impact of these genetic variations is indeed during early cortical development,” the authors of the study wrote, “this would be consistent with our inability to detect perturbed miR-9 levels in post-mortem [brain tissue] … ”
The sample size of the Mount Sinai study was admittedly small – just four schizophrenic patients — but in a second, slightly larger study of 14 patients, conducted by the National Institutes of Health, the results were replicated.
“These findings support a model of an extremely complex genetic architecture underlying schizophrenia risk,” the report said, “one in which miR-9 is just one of many factors contributing to schizophrenia predisposition in a subset of patients.”
More than 1,000 genes have been associated with schizophrenia in recent years, but the social significance of these most recent findings, said Brennand, cannot be overstated.
“What I hope it tells parents is that it’s not their fault,” said Brennand, who conducts research at Mount Sinai’s School of Medicine in New York City. “If science can do anything, even before new treatments, maybe we can at least change attitudes.”
< http://news.nationalpost.com/health/some-children-born-with-the-genetic-risk-for-schizophrenia-scientists-say >
Related:
‘I’m almost giddy’: Scientists open the ‘black box’ of schizophrenia with dramatic genetic finding < http://news.nationalpost.com/health/im-almost-giddy-scientists-open-the-black-box-of-schizophrenia-with-dramatic-genetic-finding >
Tags: disabilities, featured, mental Health
This entry was posted on Saturday, April 23rd, 2016 at 10:30 am and is filed under Health Debates. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.
Leave a Reply
Recent Comments