We have posted a comment in PubMed Commons about Baert et al. “Thorough in silico and in vitro cDNA analysis of 21 putative BRCA1 and BRCA2 splice variants and a complex tandem duplication in BRCA2, allowing the identification of activated cryptic splice donor sites in BRCA2 exon 11.” (2017) (doi: 10.1002/humu.23390). The updated comments can be found at: https://www.ncbi.nlm.nih.gov/pubmed/29280214#comments. They have been highlighted twice by PubMed Commons as a “Top Comment”.
Twenty one BRCA1 and BRCA2 mRNA splice site variants were analyzed by semi-quantitative RT-PCR, with commercial software that scores putative splice sites by ad hoc methods, and with bioinformatic models based on Adaboost and Random Forest, which are general machine learning approaches. The authors cited our review on interpretation of splicing mutations (Caminsky N, 2014), however the analytic approach described in that paper was not evaluated. As an update to our previous BRCA mutation study (Mucaki EJ, 2011), we carried out information theory-based splicing analysis of all potential splicing mutations listed in Supplemental Table S3. The splicing consequences of all variants were accurately predicted by information analysis. We also report results of exon definition-based mRNA splicing mutation analysis (Mucaki EJ, 2013), which infers relative abundance of wild type and mutated splice isoforms from total splicing information content of each prospective exon. Due to length limitations in PubMed Commons commenting system, detailed results for each variant are described in: https://doi.org/10.5281/zenodo.1146708
Also, during our analysis, some inconsistencies in mutation designation or interpretation were noted in the paper: (1) The complex BRCA2duplication described in this article (c.425+415_4780dup[insGATCGCAGTGA]) is sometimes referred to as “c.426-415_4780dup[insGATCGCAGTGA]” (e.g. the title of Figure 5, and Suppl. Table S3), which are not congruent mutations. The true mutation is likely the former, as the Figure 5 legend describes an mRNA splice form that includes 293nt of intron 4. If the duplication was c.426-415_4780dup[insGATCGCAGTGA], the intron inclusion would only be 205nt long. (2) We report an additional inconsistency in regards to Figure 5: The legend of Figure 5E describes a splice form where a truncated exon 11 junctions with the aforementioned 11nt insertion. However, the diagram and the electropherogram in Figure 5e shows exon 11 (ending at c.2398) sharing a junction with the beginning of exon 5. The latter is most likely the correct isoform, as an acceptor is not predicted at the junction between c.4780 and the 11nt insertion.