In Nature Genetics this week, researchers from the cross-disorder group of the Psychiatric Genomics Consortium publish the results of a genome-wide SNP study that identified a genetic relationship between five psychiatric disorders. Using genotype data from the consortium’s databases in schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorders, and attention-deficit/hyperactivity disorder, they applied univariate and bivariate methods to estimate genetic variation within and covariation between the disorders. The team found high genetic correlation between schizophrenia and bipolar disorder; moderate correlation between schizophrenia and major depressive disorder, bipolar disorder and major depressive disorder, and ADHD and major depressive disorder; and low correlation between schizophrenia and ASD. "This empirical evidence of shared genetic etiology for psychiatric disorders can inform nosology and encourages the investigation of common pathophysiologies for related disorders," the researchers note.
Meanwhile, in Nature Methods, a group from Harvard University and the Massachusetts Institute of Technology published a method for fluorescence in situ identification of individual mRNA molecules. The method allows for quantitative and accurate measurement, in single cells, of allele-specific transcripts that differ by only a few nucleotides, the researchers say. Using a combination of allele-specific and non–allele-specific probe libraries, the investigators were able to achieve greater than 95 percent detection accuracy.