Genetic testing and clinical relevance of patients with thoracic aortic aneurysm and dissection in northwestern China

Prevalence and Influence of Genetic Variants on Follow-Up Results in Patients Surviving Thoracic Aortic Therapy

Background/Objective: To investigate the prevalence and effects of genetic variants (GVs) in survivors of thoracic aortic dissection/aneurysm repair. Methods: Patients aged 18-80 years who survived follow-up after cardiosurgical or endovascular repair of thoracic aortic aneurysm or dissection at a single tertiary center between 2008 and 2019 and underwent genetic testing were enrolled. The exclusion criteria were age >60 years, no offspring, and inflammatory- or trauma-related pathogenesis. Follow-up entailed computed tomography-angiography at 3 and 9 months and annually thereafter. All patients underwent genetic analyses of nine genes using next-generation sequencing. In cases of specific suspicion, the analysis was expanded to include 32 genes. Results: The study included 95 patients. The follow-up period was 3 ± 2.5 years. GVs were detected in 40% of patients. Correlation analysis according to primary diagnosis showed no significant correlation in disease persistence, progression, or in reintervention rates in aneurysm patients and a correlation of disease persistence with genetic variants according to variant class in dissection patients (p = 0.037). Correlation analysis according to follow-up CD finding revealed that patients with detected dissection, irrespective of original pathology, showed a strong correlation with genetic variants regarding disease progression and reintervention rates (p = 0.012 and p = 0.047, respectively). Conclusions: The prevalence of VUS is high in patients with aortic pathology. In patients with dissected aorta in the follow-up, irrespective of original pathology, genetic variants correlate with higher reintervention rates, warranting extended-spectrum genetic testing. The role of VUS may be greater than is currently known.

Copy-number variants in the ACMG secondary finding genes: A reporting framework for clinical cytogeneticists

Purpose

To determine the pathogenicity and frequency of copy-number variants (CNV) in the 81 secondary finding (SFv3.2) genes recommended by the American College of Medical Genetics and Genomics (ACMG).

Methods

Review of published evidence on pathogenicity of partial or complete copy-number losses or gains in ACMG SFv3.2 was performed. Frequency of reportable CNVs in the ACMG SFv3.2 genes was investigated among 10,959 patients tested by chromosomal microarray analysis in a single academic testing laboratory at the University of Pittsburgh Medical Center during 2011 to 2023.

Results

We identified 58 ACMG SFv3.2 genes for which sufficient evidence supports reporting of partial or complete copy-number losses as secondary findings. On the contrary, reporting of copy-number gains was not supported by evidence in any of the ACMG SFv3.2 genes. Overall, CNVs in SFv3.2 genes were detected in 32 of 10,959 (0.29% or 1 in 343) patients in our cohort.

Conclusion

This study provides a framework for consistent reporting of CNVs, detected by chromosomal microarray analysis, exome, or genome sequencing, in any of the ACMG SFv3.2 genes. To our knowledge, this is the largest cohort of patients studied for estimation of frequency of reportable CNVs in the ACMG SFv3.2 genes.

Molecular characterization and clinical investigation of patients with heritable thoracic aortic aneurysm and dissection

OBJECTIVES

Thoracic aortic aneurysm and dissection has a genetic predisposition and a variety of clinical manifestations. This study aimed to investigate the clinical and molecular characterizations of patients with thoracic aortic aneurysm and dissection and further explore the relationship between the genotype and phenotype, as well as their postoperative outcomes.

METHODS

A total of 1095 individuals with thoracic aortic aneurysm and dissection admitted to our hospital between 2013 and 2022 were included. Next-generation sequencing and multiplex ligation-dependent probe amplification were performed, and mosaicism analysis was additionally implemented to identify the genetic causes.

RESULTS

A total of 376 causative variants were identified in 83.5% of patients with syndromic thoracic aortic aneurysm and dissection and 18.7% of patients with nonsyndromic thoracic aortic aneurysm and dissection, including 8 copy number variations and 2 mosaic variants. Patients in the "pathogenic" and "variant of uncertain significance" groups had younger ages of aortic events and higher aortic reintervention risks compared with genetically negative cases. In addition, patients with FBN1 haploinsufficiency variants had shorter reintervention-free survival than those with FBN1 dominant negative variants.

CONCLUSIONS

Our data expanded the genetic spectrum of heritable thoracic aortic aneurysm and dissection and indicated that copy number variations and mosaic variants contributed to a small proportion of the disease-causing alterations. Moreover, positive genetic results might have a possible predictive value for aortic event severity and postoperative risk stratification.

Applying multi-omics techniques to the discovery of biomarkers for acute aortic dissection

Acute aortic dissection (AAD) is a cardiovascular disease that manifests suddenly and fatally. Due to the lack of specific early symptoms, many patients with AAD are often overlooked or misdiagnosed, which is undoubtedly catastrophic for patients. The particular pathogenic mechanism of AAD is yet unknown, which makes clinical pharmacological therapy extremely difficult. Therefore, it is necessary and crucial to find and employ unique biomarkers for Acute aortic dissection (AAD) as soon as possible in clinical practice and research. This will aid in the early detection of AAD and give clear guidelines for the creation of focused treatment agents. This goal has been made attainable over the past 20 years by the quick advancement of omics technologies and the development of high-throughput tissue specimen biomarker screening. The primary histology data support and add to one another to create a more thorough and three-dimensional picture of the disease. Based on the introduction of the main histology technologies, in this review, we summarize the current situation and most recent developments in the application of multi-omics technologies to AAD biomarker discovery and emphasize the significance of concentrating on integration concepts for integrating multi-omics data. In this context, we seek to offer fresh concepts and recommendations for fundamental investigation, perspective innovation, and therapeutic development in AAD.

HTAADVar: Aggregation and fully automated clinical interpretation of genetic variants in heritable thoracic aortic aneurysm and dissection

PURPOSE

Early detection and pathogenicity interpretation of disease-associated variants are crucial but challenging in molecular diagnosis, especially for insidious and life-threatening diseases, such as heritable thoracic aortic aneurysm and dissection (HTAAD). In this study, we developed HTAADVar, an unbiased and fully automated system for the molecular diagnosis of HTAAD.

METHODS

We developed HTAADVar (http://htaadvar.fwgenetics.org) under the American College of Medical Genetics and Genomics/Association for Molecular Pathology framework, with optimizations based on disease- and gene-specific knowledge, expert panel recommendations, and variant observations. HTAADVar provides variant interpretation with a self-built database through the web server and the stand-alone programs.

RESULTS

We constructed an expert-reviewed database by integrating 4373 variants in HTAAD genes, with comprehensive metadata curated from 697 publications and an in-house study of 790 patients. We further developed an interpretation system to assess variants automatically. Notably, HTAADVar showed a multifold increase in performance compared with public tools, reaching a sensitivity of 92.64% and specificity of 70.83%. The molecular diagnostic yield of HTAADVar among 790 patients (42.03%) also matched the clinical data, independently demonstrating its good performance in clinical application.

CONCLUSION

HTAADVar represents the first fully automated system for accurate variant interpretation for HTAAD. The framework of HTAADVar could also be generalized for the molecular diagnosis of other genetic diseases.

Targeted Panel Sequencing Identifies an Intronic c.5225-3C>G Variant of the FBN1 Gene Causing Sporadic Marfan Syndrome with Annuloaortic Ectasia

Marfan syndrome (MFS) is a hereditary connective tissue disease whose clinical severity varies widely. Mutations of the FBN1 gene encoding fibrillin-1 are the most common genetic cause of Marfanoid habitus; however, about 10% of MFS patients are unaware of their genetic defects. Herein, we report a Korean patient with MFS and annuloaortic ectasia caused by an intronic c.5225-3C>G variant of the FBN1 gene identified by targeted panel sequencing. The reverse transcription analysis of FBN1 revealed that the intron 43 sequence from positions c.5297-1516 to c.5297-1 was retained at the coding sequence as a consequence of the c.5225-3C>G variant enhancing a cryptic splice acceptor site (c.5297-1518_5297-1517AG) in intron 43. The retained sequence of the part of intron 43 caused the same effect as insertion mutation (NM_000138.5:c.5297_c.5298ins5297-1516_5297-1), resulting in a frameshift mutation resulting in p.Ile1767Trpfs*3. The patient underwent an urgent modified Bentall operation with a 29 mm mechanical valve for annuloaortic ectasia and severe aortic valve regurgitation. This report emphasizes the need for functional investigations into the diagnostic workflows of certain diseases or gene panels with suspected high rates of intronic variants and potential pathogenic effects. Hence, further descriptions of individuals with intronic variants causing alternative splicing expected to have pathogenic effects at different transcript levels are crucial for improving our understanding.

Genetic testing and clinical relevance of patients with thoracic aortic aneurysm and dissection in northwestern China

BACKGROUND

Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening pathology that remains a challenge worldwide. Up to 40% of TAAD cases are hereditary with complex heterogeneous genetic backgrounds. The purposes of this study were to determine the diagnostic rate of patients with TAAD, investigate the molecular pathologic spectrum of TAAD by next-generation sequencing (NGS), and explore the future preclinical prospects of genetic diagnosis in patients at high -risk of study.

METHODS

NGS was used to screen 15 genes associated with genetic TAAD in 212 patients from northwestern China. Clinical data of patients were gathered by electrocardiography, transthoracic echocardiography, and computed tomography.

RESULTS

Of the 212 patients, 67 (31.60%) tested positive for a (likely) pathogenic variant, 42 (19.81%) had a variant of uncertain significance (VUS), and 103 (48.58%) had no variant (likely benign/benign/negative). A total of 135 reportable variants were detected in our test, among which 77 (57.04%) are first reported in this paper. A genotype-phenotype correlation of FBN1 was assessed, and the data showed that the patients with truncating and splicing mutations are more prone to developing severe aortic dissection than those with missense mutations, especially frameshift mutations (82.76% vs. 42.86%). In this study, 43 (20.28%) patients had a family history of sudden death or TAAD, whereas 132 (62.26%) did not (the remaining 37 were not available), and the positive rate of genetic testing was higher in TAAD patients with family history than in those without (76.74% vs. 18.94%).

CONCLUSION

Our study concludes that genetic variation is an important consideration in the risk stratification of individualized prediction and disease diagnosis.