Comprehensive Study Uncovers Hidden Networks Affecting Mental Illness
The first findings from a comprehensive genomic analysis of the human brain have been unveiled, potentially uncovering a good deal about the inherited component of diseases such as schizophrenia and autism. Among other discoveries, the research found certain elements within the genome’s “dark matter” which appear to regulate gene expression. Networks of genes and buried elements have also been found, which could contribute to the chance to develop disorders.
Neuropsychiatric disorders such as schizophrenia normally involve hundreds of genes, all interacting with environmental factors and contributing a small percentage to the overall risk of the disease developing. While in the past scientists have uncovered genetic variants linked to the diseases, it has never been shown how sequence changes alter the genes’ function. Some of the variants also fall in DNA regions which do not code for proteins, further obscuring the truth.
Scientists from the PsychENCODE Consortium, founded by the US National Institutes of Health, ran studies which combined several types of sequencing data from brain tissue taken from 1,866 corpses and from single brain-cell types. While studies in the past have revealed huge variation in gene expression between brains, comparing sequencing data from specific cell types with that from whole brains revealed that almost all of this variance relates to the relative proportion of different cell types in a brain, a statistic which changes with age, and in certain conditions like autism.
The data was also used to connect specific genes with non-coding DNA variants previously linked to neuropsychiatric diseases. This closes the gap in identifying those variants which influence genetic function and contribute directly schizophrenia and other diseases.