Transcript level analyses of ubiquitin ligase 3A ( UBE3A ), GABA
receptor β3 ( GABRB3 ) and small nucleoriboprotein N ( SNRPN ) in postmortem human brain tissue. (a) through (c) box-and-whisker plots diagramming transcript levels in postmortem human brain normalized to glyceraldehyde 3-phosphate dehydrogenase (GAPDH). (a) UBE3A showed a significant increase in mean values for duplication of 15q11-q13 (dup15q) compared to control (CTRL) and autism (AUT). (b) GABRB3 was lower in AUT than in CTRL, whereas dup15q samples showed a significantly increased variance compared with both AUT and CTRL. (c) SNRPN expression levels were significantly lower in dup15q than in the other groups. In addition, AUT showed significantly increased variance for SNRPN levels compared to CTRL and dup15q. Significant differences are indicated by *P < 0.05, **P < 0.01 and ***P < 0.001. Significant differences in the variance between groups were determined by Levene's test for equality of variances, which are represented in blue. Black represents significant differences in the group means as determined by t-test. (d) through (f) Histograms representing the distribution of transcript levels in individual postmortem human brain grouped by condition are shown.