Clinical Utility of Functional RNA Analysis for the Reclassification of Splicing Gene Variants in Hereditary Cancer

BackgroundThe strength of evidence supporting the validity of gene-disease relationships is variable. Hereditary cancer has the additional complexity of low or moderate penetrance for some confirmed disease-associated alleles.MethodsTo promote national consistency in interpretation of hereditary cancer/tumour gene test results, we requested opinions of representatives from Australian Family Cancer Clinics regarding the clinical utility of 157 genes initially collated for a national research project. Viewpoints were sought by initial survey, face-to-face workshop and follow-up survey. Subsequent review was undertaken by the eviQ Cancer Genetics Reference Committee, a national resource providing evidence-based and consensus-driven cancer treatment protocols.ResultsGenes were categorised by clinical actionability as: relevant for testing on presentation of common cancer/tumour types (n=45); relevant for testing in the context of specific rare phenotypes (n=74); insufficient clinical utility (n=34) or contentious clinical utility (n=3). Opinions for several genes altered during the study time frame, due to new information.ConclusionThrough an iterative process, consensus was achieved on genes with clinical utility for hereditary cancer/tumour conditions in the Australian setting. This study highlighted need for regular review of gene-disease lists, a role assumed in Australia for hereditary cancer/tumour predisposition genes by the eviQ Cancer Genetics Reference Committee.

Hypertrophic cardiomyopathy (HCM), the most common inherited heart disease, is predominantly caused by mutations in genes that encode sarcomere-associated proteins. Effective gene-based diagnosis is critical for the accurate clinical management of patients and their family members. However, the introduction of high-throughput DNA sequencing approaches for clinical diagnostics has vastly expanded the number of variants of uncertain significance, leading to many inconclusive results that limit the clinical utility of genetic testing. More recently, developments in RNA analysis have been improving diagnostic outcomes by identifying new variants that interfere with splicing. This review summarizes recent discoveries of RNA mis-splicing in HCM and provides an overview of research that aims to apply the concept of RNA therapeutics to HCM.

1524 Background: Next-generation sequencing (NGS) for tumor molecular profiling can reveal germline incidental mutations in hereditary cancer-related genes. The American College of Medical Genetics and Genomics (ACMG) has recommended that laboratories performing clinical sequencing seek and report PV and LPV in 56 genes. We assessed the prevalence of incidental germline LPV and PV in other cancer-related genes among patients undergoing hybrid capture sequencing of 201 cancer-related genes. Methods: Matched tumor and germline DNA NGS of a targeted panel of 201 genes was performed in 1000 patients (pts) with advanced or metastatic solid tumors enrolled in a molecular testing protocol (NCT01772771) in a research laboratory. We previously reported germline alterations in the putative most actionable genes as designated by ACMG (PMID: 26787237). We assessed the germline LPV and PV in 54 additional cancer-related genes. Results: Among the 1000 patients who underwent tumor and normal DNA sequencing, 37 patients (3.7%) were found to have a germline PV or LPV in the following genes: ATM (4); BAP1 (1); CDH1 (1); CDKN2A (1); CHEK1 (2); CHEK2 (10); EGFR (1); ERCC3 (4); ERCC5 (1); HNF1B (1); HRAS (1); MLL3 (1); NF1 (3); PKHD1 (4); PTCH1 (1) and SMARCA4 (1). Eight pts (22%) had previous genetic counseling and testing for various reasons, but only 3 pts (8%) had previously identified alterations (all with NF1 mutations). After discussion in our return of germline results board, it was decided to return the findings in established hereditary cancer predisposition genes with high penetrance: BAP1 (p.Y401X), CDH1 (p.C688X), CDKN2A (p.G101W), EGFR (p.T790M) and SMARCA4 (p.S332FfsX55) after validation in a CLIA laboratory. Conclusions: Return of the previously unrecognized germline LPV or PV in patients with advanced or metastatic cancers who undergo somatic profiling is of great interest. The exact genes for which the germline results should be returned is controversial. Broader genomic testing is likely to identify additional incidental germline alterations with potential clinical utility to patients and their relatives.

Recent studies indicate there is some disagreement concerning the interpretation and clinical utility of the Type V Bekesy pattern. Bekesy tracings obtained over the past six years from a sample of clinical cases were analyzed and a definition was established for the Type V pattern. This definition was applied to Bekesy tracings obtained from normal listeners, hypoacusics, and pseudohypoacusics. The Type V pattern was found frequently among pseudohypoacusics and only rarely among other individuals.

Spectral moment analysis (SMA) is an acoustic analysis tool that shows promise for enhancing our understanding of normal and disordered speech production. It can augment auditory-perceptual analysis used to investigate differences across speakers and groups and can provide unique information regarding specific aspects of the speech signal. The purpose of this paper is to illustrate the utility of SMA as a clinical measure for both clinical speech production assessment and research applications documenting speech outcome measurements. Although acoustic analysis has become more readily available and accessible, clinicians need training with, and exposure to, acoustic analysis methods in order to integrate them into traditional methods used to assess speech production.