1700 studies have reported over 1000 genes to be associated with schizophrenia, but in this PGC investigation of 150,000 people, the largest and best powered study ever undertaken of schizophrenia genetics, the vast majority of these gene findings could not be confirmed. Even if a candidate polymorphism is truly associated with a phenotype, it will be at levels difficult to detect without a design powered adequately for finding what are likely to be very small effects.
