Background: Long CAG repeats in the hKCa3 potassium channel gene have been associated with schizophrenia. We sought evidence for associations between this polymorphism and aspects of the schizophrenia phenotype.
Methods: Associations were investigated between CAG repeat length and gender, age of illness onset, and psychotic symptom dimensions in 203 unrelated individuals with DSM-IIIR schizophrenia.
Results: No association was found between CAG repeat length and gender or age of onset. Long CAG repeats were associated with higher negative symptom dimension scores.
Conclusions: This study provides preliminary evidence that genetic liability to negative symptoms in schizophrenia may be partly mediated through the hKCa3 gene.