It was the largest brain study ever: more than 200 scientists hailing from 100 institutions across the globe collaborated on mapping the human genes of more than 20,000 people that affect the brain’s resistance to a number of mental illnesses, including Alzheimer’s disease. Published April 15 in the advance online edition of Nature Genetics, the study also found that the HMGA2 gene may explain individual differences in brain size and intelligence.
“We searched for two things in this study,” said UCLA neurology professor Paul Thompson, PhD, in a press release. “We hunted for genes that increase your risk for a single disease that your children can inherit. We also looked for factors that cause tissue atrophy and reduce brain size, which is a biological marker for hereditary disorders like schizophrenia, bipolar disorder, depression, Alzheimer’s disease and dementia.”
In 2009, Thompson partnered with geneticists at the Queensland Institute for Medical Research (Brisbane, Australia) and Radboud University Nijmegen Medical Centre (The Netherlands). The researchers recruited international brain-imaging labs and pooled the resulting brain scans and genomic data. They then used this data to establish Project ENIGMA. (“ENIGMA” is short for “Enhancing Neuro Imaging Genetics through Meta-Analysis”.)
“Our individual centers couldn’t review enough brain scans to obtain definitive results,” said Thompson, who is also a professor of psychiatry at the Semel Institute for Neuroscience and Human Behavior at UCLA. “By sharing our data with Project ENIGMA, we created a sample large enough to reveal clear patterns in genetic variation and show how these changes physically alter the brain.”
From the announcement:
In the past, neuroscientists screened the genomes of people suffering from a specific brain disease and combed their DNA to uncover a common variant. In this study, Project ENIGMA researchers measured the size of the brain and its memory centers in thousands of MRI images from 21,151 healthy people while simultaneously screening their DNA.
“Earlier studies have uncovered risk genes for common diseases, yet it’s not always understood how these genes affect the brain,” explained Thompson. “This led our team to screen brain scans worldwide for genes that directly harm or protect the brain.”
UCLA press release: International team uncovers new genes that shape brain size, intelligence…