We identified 34 confirmed de novo CNVs (Table 1), a rate in all cases of 5.1%. Detailed descriptions of individual de novo CNVs are given in Supplementary Section 6 and in the Discussion section. As in an earlier study,24 the de novo rate in those with a history of psychosis in a parent was lower (1.6%) than in those without such history (5.5%), although this was not statistically significant. Parents of probands with de novos were not older at the time of birth of their children than parents of probands without de novos: (27.8 vs 28.7 years, respectively, for fathers and 25.1 vs 25.1 years for mothers). Probands with de novo CNVs (Table 1) did not differ from the rest of the probands regarding age at onset (23.9 vs 23.8 years, P=0.9) and average school results (4.5 vs 4.7, P=0.5), and both sets of probands had similar numbers of children (0.52 vs 0.59, P=0.6). In those instances (21) where it was possible to determine the parental origin, more de novos occurred in the paternal (P=14) than the maternal (n=7) genome
