{"id":4390,"date":"2018-01-13T14:35:08","date_gmt":"2018-01-13T14:35:08","guid":{"rendered":"http:\/\/www.cytognomix.com\/?p=4390"},"modified":"2018-02-04T21:17:07","modified_gmt":"2018-02-04T21:17:07","slug":"jan-13-2018-new-comment-in-pubmed-commons-on-mrna-splicing-mutations-in-brca12","status":"publish","type":"post","link":"https:\/\/www.cytognomix.com\/?p=4390","title":{"rendered":"Jan. 13 and 21, 2018.  Comments on PubMed PMID  29280214: 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."},"content":{"rendered":"<p>We have posted a comment in PubMed Commons about Baert et al. &#8220;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.&#8221; (2017) (doi: 10.1002\/humu.23390). The updated comments can be found at:\u00a0<a title=\"Comment on Baert et al. 2017\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/29280214#comments\" target=\"_blank\">https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/29280214#comments<\/a>. They have been highlighted twice by PubMed Commons as a &#8220;Top Comment&#8221;.<\/p>\n<p>NB: We have exchanged views with Dr. Claes (senior author), who has inquired about our NGS pipeline for splicing mutation analysis, <a title=\"Mutation Forecater\" href=\"http:\/\/mutationforecaster.com\" target=\"_blank\">MutationForecaster<\/a>\u00a0(<a title=\"Mutation Forecaster\" href=\"http:\/\/mutationforecaster.com\" target=\"_blank\">www<\/a><a title=\"Mutation Forecaster\" href=\"http:\/\/mutationforecaster.com\" target=\"_blank\">.mutationforecaster.com<\/a>):<\/p>\n<p style=\"padding-left: 30px;\"><a id=\"ui-ncbipopper-18\" role=\"button\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/myncbi\/peter.rogan.1\/comments\/\" class=\"broken_link\">Peter Rogan<\/a><a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/29280214#cm29280214_78253\">2018 Jan 12 2:39 p.m.<\/a>edited\u00a02 of 2 people found this helpful<\/p>\n<div style=\"padding-left: 30px;\" data-md=\"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 (&lt;PMID:25717368&gt;), however the analytic approach described in that paper was not evaluated. As an update to our previous BRCA mutation study (&lt;PMID: 21523855&gt;), 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 (&lt;PMID: 23348723&gt;), 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: &lt;https:\/\/doi.org\/10.5281\/zenodo.1146708&gt;&lt;\/p&gt;\n&lt;p&gt;Also, during our analysis, some inconsistencies in mutation designation or interpretation were noted in the paper: **(1)** The complex *BRCA2* duplication described in this article (c.425+415\\_4780dup[insGATCGCAGTGA]) is sometimes referred to as &quot;c.426-415\\_4780dup[insGATCGCAGTGA]&quot; (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.\"><\/p>\n<p style=\"padding-left: 30px;\">Twenty one\u00a0<em>BRCA1<\/em>\u00a0and\u00a0<em>BRCA2<\/em>\u00a0mRNA splice site variants were analyzed by semi-quantitative RT-PCR, with commercial software that scores putative splice sites by\u00a0<em>ad hoc<\/em>\u00a0methods, 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 (<a title=\"Interpretation of mRNA splicing mutations in genetic disease: review of the literature and guidelines for information-theoretical analysis.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/25717368\/\">Caminsky N, 2014<\/a>), however the analytic approach described in that paper was not evaluated. As an update to our previous BRCA mutation study (<a title=\"Comprehensive prediction of mRNA splicing effects of BRCA1 and BRCA2 variants.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/21523855\/\">Mucaki EJ, 2011<\/a>), 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 (<a title=\"Prediction of mutant mRNA splice isoforms by information theory-based exon definition.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/23348723\/\">Mucaki EJ, 2013<\/a>), 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:\u00a0<a href=\"https:\/\/doi.org\/10.5281\/zenodo.1146708\" class=\"broken_link\">https:\/\/doi.org\/10.5281\/zenodo.1146708<\/a><\/p>\n<p style=\"padding-left: 30px;\">Also, during our analysis, some inconsistencies in mutation designation or interpretation were noted in the paper:\u00a0<strong>(1)<\/strong>\u00a0The complex\u00a0<em>BRCA2<\/em>duplication described in this article (c.425+415_4780dup[insGATCGCAGTGA]) is sometimes referred to as &#8220;c.426-415_4780dup[insGATCGCAGTGA]&#8221; (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.\u00a0<strong>(2)<\/strong>\u00a0We 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.<\/p>\n<ul id=\"comment_list\" data-page=\"emb\" data-pcid=\"1Ng3wo_-OFLZWMLY3W2UbL0S5ooYN3HD2JSLcbbnk3bOqxlkf\">\n<li data-cmid=\"78304\"><a id=\"ui-ncbipopper-16\" role=\"button\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/myncbi\/kathleen%20b%20m.claes.1\/comments\/\" class=\"broken_link\">Kathleen B M Claes<\/a><a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/29280214#cm29280214_78304\">2018 Jan 17 10:44 a.m.<\/a>\u00a02 of 2 people found this helpful\n<div>\n<p>Dear dr Rogan, thank you very much for your constructive comments. It is very interesting to learn that your exon definition-based mRNA splicing analyses are in agreement with our cDNA analyses for all variants we studied (an overview is provided in Suppl Table S1 of our paper &#8211; not S3). I read the detailed comments on the URL you referred to. How easy can this approach be implemented in an NGS data analysis pipeline? Can you define cut-offs in this program to indicate when cDNA analysis is warranted?<\/p>\n<p>I also would like to thank you for alerting us about the typing error for the Multi-exon duplication in BRCA2 &#8211; the correct nomenclature for this duplication is indeed c.426+415_4780dup{insGATCGCAGTGA}. We corrected this in the final proofs.<\/p>\n<\/div>\n<\/li>\n<li>\n<ul>\n<li data-cmid=\"78358\"><a id=\"ui-ncbipopper-17\" role=\"button\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/myncbi\/peter.rogan.1\/comments\/\" class=\"broken_link\">Peter Rogan<\/a><a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/29280214#cm29280214_78358\">2018 Jan 21 1:20 p.m.<\/a>edited\u00a01 of 1 people found this helpful\n<div data-md=\"The results reported in Table S1 of the different bioinformatic methods were difficult for us to assess. For example, why were there no bioinformatic analyses for c.426+415_4780dup(insGATCGCAGTGA)? Our analysis includes this mutation. Model cutoffs for these bioinformatic methods are defined arbitrarily because they are based on underlying datasets with unpublished or unknown content; furthermore, the binding site models are not easily reproduced, in part because they are not actually based on binding site affinities (&lt;PMID: 23955774&gt;). &lt;\/p&gt;\n&lt;p&gt;The details of the methods and source data we use to derive our information weight matrices and the matrices themselves are available (&lt;PMID: 12668917&gt;).  The information contents of splice recognition sites or exons are expressed in units of bits, which have been formally proven to be related to binding site affinity through the second law of thermodynamics (&lt;PMID: 9446751&gt;, &lt;PMID: 9711873&gt;). In fact, relative entropy used by maxEntscan, violates the triangle inequality which is a fundamental requirement of the second law (&lt;PMID: 10534438&gt;). These articles demonstrate the cutoff for true binding sites is very close to the theoretical minimum of zero bits (Delta G = 0). We have also demonstrated this thermodynamic threshold holds for other types of binding sites (&lt;PMID: 27899659&gt;).&lt;\/p&gt;\n&lt;p&gt;Our pipeline for NGS data analysis has been validated extensively (&lt;PMID: 23499923&gt;, &lt;PMID: 24741438&gt;, &lt;PMID: 25394353&gt;, &lt;PMID: 26898890&gt;, &lt;PMID: 27067391&gt;, &lt;PMID: 28664506&gt;, &lt;PMID: 29236234&gt;). The URL of the [MutationForecaster](http:\/\/www.mutationforecaster.com) pipeline is given in the [document linked](https:\/\/doi.org\/10.5281\/zenodo.1146708) to our previous PubMed Commons post .\"><\/p>\n<p>The results reported in Table S1 of the different bioinformatic methods were difficult for us to assess. For example, why were there no bioinformatic analyses for c.426+415_4780dup(insGATCGCAGTGA)? Our analysis includes this mutation. Model cutoffs for these bioinformatic methods are defined arbitrarily because they are based on underlying datasets with unpublished or unknown content; furthermore, the binding site models are not easily reproduced, in part because they are not actually based on binding site affinities (<a title=\"Best practices for evaluating mutation prediction methods.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/23955774\/\">Rogan PK, 2013<\/a>).<\/p>\n<p>The details of the methods and source data we use to derive our information weight matrices and the matrices themselves are available (<a title=\"Information theory-based analysis of CYP2C19, CYP2D6 and CYP3A5 splicing mutations.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/12668917\/\">Rogan PK, 2003<\/a>). The information contents of splice recognition sites or exons are expressed in units of bits, which have been formally proven to be related to binding site affinity through the second law of thermodynamics (<a title=\"Information content of individual genetic sequences.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/9446751\/\">Schneider TD, 1997<\/a>,\u00a0<a title=\"Information analysis of human splice site mutations.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/9711873\/\">Rogan PK, 1998<\/a>). In fact, relative entropy used by maxEntscan, violates the triangle inequality which is a fundamental requirement of the second law (<a title=\"Measuring molecular information.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/10534438\/\">Schneider TD, 1999<\/a>). These articles demonstrate the cutoff for true binding sites is very close to the theoretical minimum of zero bits (Delta G = 0). We have also demonstrated this thermodynamic threshold holds for other types of binding sites (<a title=\"Discovery and validation of information theory-based transcription factor and cofactor binding site motifs.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/27899659\/\">Lu R, 2017<\/a>).<\/p>\n<p>Our pipeline for NGS data analysis has been validated extensively (<a title=\"Interpretation, stratification and evidence for sequence variants affecting mRNA splicing in complete human genome sequences.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/23499923\/\">Shirley BC, 2013<\/a>,\u00a0<a title=\"Validation of predicted mRNA splicing mutations using high-throughput transcriptome data.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/24741438\/\">Viner C, 2014<\/a>,\u00a0<a title=\"Splicing mutation analysis reveals previously unrecognized pathways in lymph node-invasive breast cancer.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/25394353\/\">Dorman SN, 2014<\/a>,\u00a0<a title=\"Prioritizing Variants in Complete Hereditary Breast and Ovarian Cancer Genes in Patients Lacking Known BRCA Mutations.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/26898890\/\">Caminsky NG, 2016<\/a>,\u00a0<a title=\"A unified analytic framework for prioritization of non-coding variants of uncertain significance in heritable breast and ovarian cancer.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/27067391\/\">Mucaki EJ, 2016<\/a>,\u00a0<a title=\"Prevalence and spectrum of germline rare variants in BRCA1\/2 and PALB2 among breast cancer cases in Sarawak, Malaysia.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/28664506\/\">Yang XR, 2017<\/a>,\u00a0<a title=\"Assessment of the functional impact of germline BRCA1\/2 variants located in non-coding regions in families with breast and\/or ovarian cancer predisposition.\" href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/29236234\/\">Dos Santos ES, 2017<\/a>). The URL of the\u00a0<a href=\"http:\/\/www.mutationforecaster.com\/\">MutationForecaster<\/a>\u00a0pipeline is given in the\u00a0<a href=\"https:\/\/doi.org\/10.5281\/zenodo.1146708\" class=\"broken_link\">document linked<\/a>\u00a0to our previous PubMed Commons post .<\/p>\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/div>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/www.cytognomix.com\/wp-content\/uploads\/2018\/01\/PubMedCommonsentry1-12-2018.png\"><img loading=\"lazy\" class=\"alignleft size-full wp-image-4391\" alt=\"PubMedCommonsentry1-12-2018\" src=\"http:\/\/www.cytognomix.com\/wp-content\/uploads\/2018\/01\/PubMedCommonsentry1-12-2018.png\" width=\"759\" height=\"750\" srcset=\"https:\/\/www.cytognomix.com\/wp-content\/uploads\/2018\/01\/PubMedCommonsentry1-12-2018.png 759w, https:\/\/www.cytognomix.com\/wp-content\/uploads\/2018\/01\/PubMedCommonsentry1-12-2018-300x296.png 300w\" sizes=\"(max-width: 759px) 100vw, 759px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>We have posted a comment in PubMed Commons about Baert et al. &#8220;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.&#8221; (2017) (doi: 10.1002\/humu.23390). The updated comments can [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[6],"tags":[],"_links":{"self":[{"href":"https:\/\/www.cytognomix.com\/index.php?rest_route=\/wp\/v2\/posts\/4390"}],"collection":[{"href":"https:\/\/www.cytognomix.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cytognomix.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cytognomix.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cytognomix.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4390"}],"version-history":[{"count":5,"href":"https:\/\/www.cytognomix.com\/index.php?rest_route=\/wp\/v2\/posts\/4390\/revisions"}],"predecessor-version":[{"id":4417,"href":"https:\/\/www.cytognomix.com\/index.php?rest_route=\/wp\/v2\/posts\/4390\/revisions\/4417"}],"wp:attachment":[{"href":"https:\/\/www.cytognomix.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4390"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cytognomix.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4390"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cytognomix.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4390"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}