Reevaluating the Genetic Contribution of Monogenic Dilated Cardiomyopathy
CIRCULATION
Authors: Mazzarotto, Francesco; Tayal, Upasana; Buchan, Rachel J.; Midwinter, William; Wilk, Alicja; Whiffin, Nicola; Govind, Risha; Mazaika, Erica; de Marvao, Antonio; Dawes, Timothy J. W.; Felkin, Leanne E.; Ahmad, Mian; Theotokis, Pantazis, I; Edwards, Elizabeth; Ing, Alexander Y.; Thomson, Kate L.; Chan, Laura L. H.; Sim, David; Baksi, A. John; Pantazis, Antonis; Roberts, Angharad M.; Watkins, Hugh; Funke, Birgit; O'Regan, Declan P.; Olivotto, Iacopo; Barton, Paul J. R.; Prasad, Sanjay K.; Cook, Stuart A.; Ware, James S.; Walsh, Roddy
Abstract
Background: Dilated cardiomyopathy (DCM) is genetically heterogeneous, with >100 purported disease genes tested in clinical laboratories. However, many genes were originally identified based on candidate-gene studies that did not adequately account for background population variation. Here we define the frequency of rare variation in 2538 patients with DCM across protein-coding regions of 56 commonly tested genes and compare this to both 912 confirmed healthy controls and a reference population of 60 706 individuals to identify clinically interpretable genes robustly associated with dominant monogenic DCM. Methods: We used the TruSight Cardio sequencing panel to evaluate the burden of rare variants in 56 putative DCM genes in 1040 patients with DCM and 912 healthy volunteers processed with identical sequencing and bioinformatics pipelines. We further aggregated data from 1498 patients with DCM sequenced in diagnostic laboratories and the Exome Aggregation Consortium database for replication and meta-analysis. Results: Truncating variants in TTN and DSP were associated with DCM in all comparisons. Variants in MYH7, LMNA, BAG3, TNNT2, TNNC1, PLN, ACTC1, NEXN, TPM1, and VCL were significantly enriched in specific patient subsets, with the last 2 genes potentially contributing primarily to early-onset forms of DCM. Overall, rare variants in these 12 genes potentially explained 17% of cases in the outpatient clinic cohort representing a broad range of adult patients with DCM and 26% of cases in the diagnostic referral cohort enriched in familial and early-onset DCM. Although the absence of a significant excess in other genes cannot preclude a limited role in disease, such genes have limited diagnostic value because novel variants will be uninterpretable and their diagnostic yield is minimal. Conclusions: In the largest sequenced DCM cohort yet described, we observe robust disease association with 12 genes, highlighting their importance in DCM and translating into high interpretability in diagnostic testing. The other genes analyzed here will need to be rigorously evaluated in ongoing curation efforts to determine their validity as Mendelian DCM genes but have limited value in diagnostic testing in DCM at present. This data will contribute to community gene curation efforts and will reduce erroneous and inconclusive findings in diagnostic testing.
Identification of differentially-expressed genes in lung squamous cell carcinoma and correlation levels with prognosis through integrated bioinformatics analysis
INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL MEDICINE
Authors: Zhang, Licui; Zhong, Chen; Gu, Yang; Ma, Yajing; Ming, Xinliang; Su, Xin; Liu, Min
Abstract
Background: The aim of the current study was to screen differentially-expressed genes (DEGs) relevant to cancer progression and prognosis of squamous cell lung carcinoma (SqCLC). Methods: DEGs mRNA expression data of SqCLC was screened from the Oncomine database. This data was further analyzed by comparing tumor tissues to normal tissues. Prognostic values of DEGs relevant to SqCLC were investigated using the "Kaplan-Meier Plotter" (KM plotter) database. Bioinformation for included genes was analyzed by gene GO and KEGG enrichment, aiming to explain the potential roles of identified genes in SqCLC. Protein-protein interaction (PPI) of the genes was evaluated using the STRING database. Results: Four independent microarray datasets relevant to SqCLC were identified in the Oncomine database, with the top 10 consistently upregulated and top 10 consistently downregulated genes included in the present analysis. Significant differences of overall survival (OS) were correlated with SMC4, HIST2H2AA3, GMPS, CKS1B, POLR2H, PDCD10, PLOD2, DVL3, C-type CLEC3B, TNNC1, FAM107A, FYR, MEF2C, SLIT3, CX3CR1, C17orf91, LIM, and LIMCH1 (all P < 0.05). Possible protein-protein interaction analysis of the top 20 dysregulated genes showed that proteins of SMC4, POLR2H, and NCBP2 in upregulated genes and TNNC1 and MEF2C in downregulated genes interacted with more than 5 other proteins. This may play an important role in the development of SqCLC. Conclusion: MC4, POLR2H. TNNC1, and MEF2C genes were dysregulated in SqCLC. Thus, they may play an essential role in the development of SqCLC, as biomarkers for patient prognosis.