A genome-wide SNP analysis found that five mental disorders share four risk loci. The researchers from the Cross-Disorder Group of the Psychiatric Genomics Consortium report in The Lancet that two of the four loci could be traced to genes encoding two subunits, CACNA1C and CACNB2, of L-type voltage-gated calcium channels.
The researchers examined the genomes of 33,332 people with attention deficit hyperactivity disorder, autism, bipolar disorder, major depression, or schizophrenia, and 27,888 controls, all with European ancestry. From this, they found those four risk loci. Pathway analysis, they add, indicates that the calcium channel signaling gene may play a role in each of the disorders.
Jordan Smoller, a member of the consortium and an author on the paper, tells the New York Times that "the calcium channel findings suggest that perhaps — and this is a big if — treatments to affect calcium channel functioning might have effects across a range of disorders."
In a related comment in The Lancet, Alessandro Serrettia and Chiara Fabbria from the University of Bologna note that these finding bolster previous evidence of pleiotropy in complex disorders.
They add that "the present study might contribute to future [disease description] systems, which could be based not only on statistically determined clinical categories, but also on biological pathogenic factors that are pivotal to the identification of suitable treatments."