On 2015 Apr 22, Bernard J Crespi commented:

With regard to interpretation of the results of this article, do note that of the four schizophrenia patients described here with maternal duplications, one had a duplication that spanned BP1-BP3, two showed duplications of BP2-BP3, and one had a duplication from BP1 to a region between BP4 and BP5. By contrast, of the comparison subjects with maternal duplications, two had BP1-BP3 duplications and one had a duplication of BP2-BP3. These duplications are thus rather heterogeneous, which complicates inferences regarding causation.

Restricting the analysis to the BP2-BP3 region (and noting also that BP1-BP2 region deletions have been associated statistically with schizophrenia in previous work), yields two patients and one control with the maternal duplication (Fisher’s exact test, p = 0.061). If the BP2-BP3 duplication is considered regardless of parental origin, then two patients and two controls show the duplications (Fisher's exact test, P = 0.10). It would thus be useful if, at some point, further analysis could be done with larger samples of individuals with relevant duplications.

With regard to the causal genes, a newly-published study (Noor et al. 2015) shows that duplications encompassing just the maternally-expressed, imprinted gene UBE3A, which is in the BP2-BP3 region, segregate with psychiatric diagnoses including schizophrenia, anxiety and depression, in an extended pedigree.

Reference

Noor A, Dupuis L, Mittal K, Lionel AC, Marshall CR, Scherer SW, Stockley T, Vincent JB, Mendoza-Londono R, Stavropoulos DJ. 15q11.2 Duplication Encompassing only the UBE3A Gene is Associated with Developmental Delay and Neuropsychiatric Phenotypes. Hum Mutat. 2015 Apr 17. doi: 10.1002/humu.22800.

On 2015 Apr 22, Bernard J Crespi commented:

With regard to interpretation of the results of this article, do note that of the four schizophrenia patients described here with maternal duplications, one had a duplication that spanned BP1-BP3, two showed duplications of BP2-BP3, and one had a duplication from BP1 to a region between BP4 and BP5. By contrast, of the comparison subjects with maternal duplications, two had BP1-BP3 duplications and one had a duplication of BP2-BP3. These duplications are thus rather heterogeneous, which complicates inferences regarding causation.

Restricting the analysis to the BP2-BP3 region (and noting also that BP1-BP2 region deletions have been associated statistically with schizophrenia in previous work), yields two patients and one control with the maternal duplication (Fisher’s exact test, p = 0.061). If the BP2-BP3 duplication is considered regardless of parental origin, then two patients and two controls show the duplications (Fisher's exact test, P = 0.10). It would thus be useful if, at some point, further analysis could be done with larger samples of individuals with relevant duplications.

With regard to the causal genes, a newly-published study (Noor et al. 2015) shows that duplications encompassing just the maternally-expressed, imprinted gene UBE3A, which is in the BP2-BP3 region, segregate with psychiatric diagnoses including schizophrenia, anxiety and depression, in an extended pedigree.

Reference

Noor A, Dupuis L, Mittal K, Lionel AC, Marshall CR, Scherer SW, Stockley T, Vincent JB, Mendoza-Londono R, Stavropoulos DJ. 15q11.2 Duplication Encompassing only the UBE3A Gene is Associated with Developmental Delay and Neuropsychiatric Phenotypes. Hum Mutat. 2015 Apr 17. doi: 10.1002/humu.22800.