Approximately 89% of the replication samples were families from the National Institute of Mental Health repository, and the remaining 11% were collected by one of us (L.E.D.). None of these samples was used in the prior analyses, so this replication effort was completely independent. Each family included at least 1 subject with a DSM-III-R diagnosis of SCZ. After quality control, 6298 individuals (3286 cases) from 1811 families remained.
