TCD Researchers Identify New Gene that influences Human Intelligence

Posted on: 24 October 2009

A new genetic variant that influences human intelligence has been discovered by researchers from the Neuropsychiatric Genetics Research Group (NRG) at Trinity College Dublin. The findings have just been recently published in the international  journal, Archives of General Psychiatry.

The study which was an international collaboration with researchers from the Universities of Cardiff and Munich, was led by TCD researchers Dr Gary Donohoe, Dr Aiden Corvin, Dr Derek Morris, and Professor Michael Gill of the NRG and Department of Psychiatry, TCD and sponsored by Science Foundation Ireland, the Wellcome Trust and NARSAD.

The researchers identified the new genetic variant within a gene called NOS1. The authors found that carriers of this gene variant that has been previously associated with an increased risk of schizophrenia performed on average 5 verbal IQ points below non-carriers in patients with schizophrenia. Interestingly, the same difference of 5 verbal IQ points was also observed in controlled tests involving healthy participants. The researchers were then able to replicate these findings in large German samples of both patients with schizophrenia and further controlled experiments involving healthy participants. Similar findings were also observed for the cognitive ability of working memory, an aspect of cognition highly correlated with human intelligence.

Commenting on these findings Dr Gary Donohoe said: “Although the genetics of human intelligence has been more widely studied than any other human trait, pinning down the specific molecular variants involved has been slow, probably due to the complexity of IQ and the large number of variants involved. While further studies will be required to determine the true size of NOS1’s effect on human cognition, these data support the view that some genes may affect both cognition and risk for psychiatric illness. This is important not just for understanding the biological basis for cognition and psychiatric illness but also for developing new treatment targets for these disorders.”

For further information on the Neuropsychiatric Genetics Research Group, click on:
www.tcd.ie/medicine/psychiatry/research/neuropsychiatric-genetics/