In our previous report on twin pairs concordant and discordant for bipolar disorder, we found significant genetic overlap between bipolar disorder and P50 sensory gating.
The alpha7 nicotinic acetylcholine receptor gene (CHRNA7) is located at 15q13-q14 in a region that is strongly linked to the P50 sensory gating deficit, an endophenotype of schizophrenia and bipolar disorder.
The P50 response was collected in a conditioning (C)--testing (T) paradigm from 42 outpatients with bipolar 1 disorder who had experienced psychotic symptoms and 44 of their unaffected first-degree relatives, all from families multiply affected with bipolar disorder or another non-organic psychotic disorder; 48 healthy control subjects were also studied.
Markers in the vicinity of the CHRNA7 gene at 15q13-q14 have been linked with an endophenotype of schizophrenia, P50 sensory gating disorder, with schizophrenia itself and with bipolar disorder.