The BIG project

The aim of the Brain Imaging Genetics (BIG) project is to investigate genetic influences on brain function and brain structure. For this, a continuously growing database has been created with data from whole genome genotyping and brain Magnetic Resonance Imaging (MRI). As of November 2011 we have genetic and structural image data for roughly 1500 healthy adult subjects, with some cognitive data for a subset of the overall sample. BIG is a collaboration between the Donders Center for Cognitive Neuroimaging and the Department of Human Genetics of the Radboud University Medical Centre Nijmegen, and the Max Planck Institute for Psycholinguistics.

Research objectives and possibilities

The BIG database is a valuable resource for studying effects of variations in the genome on brain volumetry/morphology and cognition.

From gene to brain:

Many neurologic and psychiatric disorders, like Alzheimers Disease, ADHD and schizophrenia, have genetic etiologies. We know that these disorders of the brain are highly heritable and some risk genes have been identified. However, how genes influence the disease phenotype remains largely unknown. In BIG we can study the effects of known risk genes of these disorders on characteristics of the brain.

As well as studying genes related to disorders, it is also relevant to study the effects of genes involved in normal cognitive functioning, to better understand the neurobiological mechanisms underlying these processes, which could be a starting point for understanding cognitive dysfunction.

From brain to gene:

In BIG it is also possible to perform genome wide association studies (GWAS) on brain traits. This way we can identify new genes associated with cortical and subcortical brain volumes, and with the other cognitive and behavioral traits included in BIG. The results from these GWAS analysis generate new candidate genes for future research.

Since effects of genes are often very small, large cohorts are necessary to study the effects of genes. BIG is among the largest imaging genetics studies in the world. However, even our large numbers are sometimes not enough to find genome wide significant effects. Therefore BIG is also part of the ENIGMA consortium (more info can be found here  http://enigma.loni.ucla.edu/).