Recessive Fanconi anemia (FA) phenotype is used in classification of , and variants with respect to dominant hereditary breast-ovarian cancer syndrome. We assessed its utility by examining the spectrum of phenotypes observed in individuals biallelic for , or pathogenic variants, and exploring the relationship between cancer presentation and allele severity score based on variant molecular features. A data collection instrument comprising 158 Human Phenotype Ontology (HPO) terms was used to document clinical features for individuals with FA from published and/or prospectively collected (total n=172, 43 previously unpublished) phenotypic data.
View Article and Find Full Text PDFWhen investigating whether a variant identified by diagnostic genetic testing is causal for disease, applied genetics professionals evaluate all available evidence to assign a clinical classification. Functional assays of higher and higher throughput are increasingly being generated and, when appropriate, can provide strong functional evidence for or against pathogenicity in variant classification. Despite functional assay data representing unprecedented value for genomic diagnostics, challenges remain around the application of functional evidence in variant curation.
View Article and Find Full Text PDFTo determine if a variant identified by diagnostic genetic testing is causal for disease, applied genetics professionals evaluate all available evidence to assign a clinical classification. Experimental assay data can provide strong functional evidence for or against pathogenicity in variant classification, but appears to be underutilised. We surveyed genetic diagnostic professionals in Australasia to assess their application of functional evidence in clinical practice.
View Article and Find Full Text PDFReanalyzing stored genomic data over time is highly effective in increasing diagnostic yield in rare disease. Automation holds the promise of delivering the benefits of reanalysis at scale. Our study aimed to understand current reanalysis practices among Australian clinical and laboratory genetics services and explore attitudes towards large-scale automated re-analysis.
View Article and Find Full Text PDFBackground: Reports of dual carriers of pathogenic BRCA1 variants in trans are extremely rare, and so far, most individuals have been associated with a Fanconi Anemia-like phenotype.
Methods: We identified two families with a BRCA1 in-frame exon 20 duplication (Ex20dup). In one male individual, the variant was in trans with the BRCA1 frameshift variant c.
Australian Genomics is a national collaborative partnership of more than 100 organizations piloting a whole-of-system approach to integrating genomics into healthcare, based on federation principles. In the first five years of operation, Australian Genomics has evaluated the outcomes of genomic testing in more than 5,200 individuals across 19 rare disease and cancer flagship studies. Comprehensive analyses of the health economic, policy, ethical, legal, implementation and workforce implications of incorporating genomics in the Australian context have informed evidence-based change in policy and practice, resulting in national government funding and equity of access for a range of genomic tests.
View Article and Find Full Text PDFApproaches to reporting clinically important genetic findings unrelated to the initial test request vary internationally. We sought to investigate practices regarding the management and return of these findings in Australia. Australian clinically accredited genetic testing laboratories were surveyed in 2017 and 2020 regarding their opinions on issues relating to the return of clinically important genetic findings unrelated to the initial test request.
View Article and Find Full Text PDFSharing genomic variant interpretations across laboratories promotes consistency in variant assertions. A landscape analysis of Australian clinical genetic-testing laboratories in 2017 identified that, despite the national-accreditation-body recommendations encouraging laboratories to submit genotypic data to clinical databases, fewer than 300 variants had been shared to the ClinVar public database. Consultations with Australian laboratories identified resource constraints limiting routine application of manual processes, consent issues, and differences in interpretation systems as barriers to sharing.
View Article and Find Full Text PDFSkipping of BRCA2 exon 3 (∆E3) is a naturally occurring splicing event, complicating clinical classification of variants that may alter ∆E3 expression. This study used multiple evidence types to assess pathogenicity of 85 variants in/near BRCA2 exon 3. Bioinformatically predicted spliceogenic variants underwent mRNA splicing analysis using minigenes and/or patient samples.
View Article and Find Full Text PDFFanconi anaemia due to biallelic loss of (Fanconi anaemia subtype D1) is traditionally diagnosed during childhood with cancer rates historically reported as 97% by 5.2 years. This report describes an adult woman with a history of primary ovarian failure, who was diagnosed with gastrointestinal adenocarcinoma and -associated Fanconi anaemia at 23 years of age, only after she suffered severe chemotherapy toxicity.
View Article and Find Full Text PDFBackground: The 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.
Methods: To 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.
The multifactorial likelihood analysis method has demonstrated utility for quantitative assessment of variant pathogenicity for multiple cancer syndrome genes. Independent data types currently incorporated in the model for assessing BRCA1 and BRCA2 variants include clinically calibrated prior probability of pathogenicity based on variant location and bioinformatic prediction of variant effect, co-segregation, family cancer history profile, co-occurrence with a pathogenic variant in the same gene, breast tumor pathology, and case-control information. Research and clinical data for multifactorial likelihood analysis were collated for 1,395 BRCA1/2 predominantly intronic and missense variants, enabling classification based on posterior probability of pathogenicity for 734 variants: 447 variants were classified as (likely) benign, and 94 as (likely) pathogenic; and 248 classifications were new or considerably altered relative to ClinVar submissions.
View Article and Find Full Text PDFThe vocabulary currently used to describe genetic variants and their consequences reflects many years of studying and discovering monogenic disease with high penetrance. With the recent rapid expansion of genetic testing brought about by wide availability of high-throughput massively parallel sequencing platforms, accurate variant interpretation has become a major issue. The vocabulary used to describe single genetic variants in silico, in vitro, in vivo and as a contributor to human disease uses terms in common, but the meaning is not necessarily shared across all these contexts.
View Article and Find Full Text PDFThe widespread use of next generation sequencing for clinical testing is detecting an escalating number of variants in noncoding regions of the genome. The clinical significance of the majority of these variants is currently unknown, which presents a significant clinical challenge. We have screened over 6,000 early-onset and/or familial breast cancer (BC) cases collected by the ENIGMA consortium for sequence variants in the 5' noncoding regions of BC susceptibility genes BRCA1 and BRCA2, and identified 141 rare variants with global minor allele frequency < 0.
View Article and Find Full Text PDFBreast Cancer Res Treat
November 2018
Purpose: Classification of rare BRCA1 missense variants presents a major challenge for the counseling and treatment of patients. Variant classification can be complicated by conflicting lines of evidence. BRCA1 c.
View Article and Find Full Text PDFAlthough the spliceogenic nature of the BRCA2 c.68-7T > A variant has been demonstrated, its association with cancer risk remains controversial. In this study, we accurately quantified by real-time PCR and digital PCR (dPCR), the BRCA2 isoforms retaining or missing exon 3.
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