DNA samples were obtained from the Australian Schizophrenia
Research Bank (ASRB). Subjects with schizophrenia were identified
using the Diagnostic and StatisticalManual ofMental Disorders-IV criteria.
In addition, all participants were subjected to thorough psychometric
testing to assess the extent of psychiatric illness in our schizophrenia
population, in addition to excluding the presence of mental disorders
in our control group. The battery of psychometric testing included: the
Psychosis Screener (from the Western Australian Family Study of
Schizophrenia), the Diagnostic Interview for Psychosis (ASRB modification
[20]), the Scale for the Assessment of Negative Symptoms (SANS),
the General Assessment of Functioning Scale (GAF), the International
Personality Disorder Examination Screening Questionnaire (ICD-10
Module), the Childhood Adversity Questionnaire, and the Schizotypal
Personality Questionnaire (SPQ). Subjects were matched for gender
and age and all samples were from Caucasian volunteers. The ethnic
origin of the Caucasian volunteers was determined by the participant's
response to questions regarding their birth place,