scholarly journals Novel SCN5A p.Val1667Asp Missense Variant Segregation and Characterization in a Family with Severe Brugada Syndrome and Multiple Sudden Deaths

2021 ◽  
Vol 22 (9) ◽  
pp. 4700
Author(s):  
Michelle M. Monasky ◽  
Emanuele Micaglio ◽  
Giuseppe Ciconte ◽  
Ilaria Rivolta ◽  
Valeria Borrelli ◽  
...  

Genetic testing in Brugada syndrome (BrS) is still not considered to be useful for clinical management of patients in the majority of cases, due to the current lack of understanding about the effect of specific variants. Additionally, family history of sudden death is generally not considered useful for arrhythmic risk stratification. We sought to demonstrate the usefulness of genetic testing and family history in diagnosis and risk stratification. The family history was collected for a proband who presented with a personal history of aborted cardiac arrest and in whom a novel variant in the SCN5A gene was found. Living family members underwent ajmaline testing, electrophysiological study, and genetic testing to determine genotype-phenotype segregation, if any. Patch-clamp experiments on transfected human embryonic kidney 293 cells enabled the functional characterization of the SCN5A novel variant in vitro. In this study, we provide crucial human data on the novel heterozygous variant NM_198056.2:c.5000T>A (p.Val1667Asp) in the SCN5A gene, and demonstrate its segregation with a severe form of BrS and multiple sudden deaths. Functional data revealed a loss of function of the protein affected by the variant. These results provide the first disease association with this variant and demonstrate the usefulness of genetic testing for diagnosis and risk stratification in certain patients. This study also demonstrates the usefulness of collecting the family history, which can assist in understanding the severity of the disease in certain situations and confirm the importance of the functional studies to distinguish between pathogenic mutations and harmless genetic variants.

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Stephanie M Ware ◽  
Steven E Lipshultz ◽  
Steven D Colan ◽  
Ling Shi ◽  
Charles E Canter ◽  
...  

Introduction: Pediatric cardiomyopathies are genetically heterogeneous diseases with high risk of death or cardiac transplant. Despite progress in identifying causes, the majority of cases remain idiopathic. Currrently, genetic testing is not performed in all children with cardiomyopathy. Gene identification leads to better individual risk stratification and has the potential to stimulate the development of therapies based on the underlying mutation. The aim of this study is to identify genetic mutations in pediatric cardiomyopathy patients using whole exome sequencing. Hypothesis: Sarcomeric mutations are under-diagnosed causes of all forms of cardiomyopathy in children. Methods: Probands with cardiomyopathy were recruited from 11 institutions. Results of clinical genetic testing prior to enrollment were collected. Whole exome sequencing was performed and mutations were identified in 35 genes currently available on clinical genetic testing panels. Results: The initial 154 probands subjected to exome included 78 patients with DCM, 43 with HCM, 14 with RCM, and 19 with LVNC, mixed, or unknown types. Familial disease was present in 38% and the remainder were idiopathic. Twenty-seven percent had positive clinical genetic testing prior to enrollment. Exome testing identified mutations in 38 subjects who had not had clinical testing, increasing the cohort positive testing rate to 55% (DCM, 34.6%; HCM, 74.4%; RCM, 71.4%). Forty-five percent of subjects with no family history of disease had an identifiable mutation. Conclusions: Pediatric cardiomyopathy patients have a high incidence of mutations that can be identified by clinically available genetic testing. Lack of a family history of cardiomyopathy was not predictive of normal genetic testing. These results support the broader use of genetic testing in pediatric patients with all functional phenotypes of cardiomyopathy to identify disease causation allowing better family risk stratification.


Author(s):  
Konstantinos P Letsas ◽  
George Bazoukis ◽  
Michael Efremidis ◽  
Stamatis Georgopoulos ◽  
Panagiotis Korantzopoulos ◽  
...  

Abstract Aims Risk stratification in Brugada syndrome (BrS) still represents an unsettled issue. In this multicentre study, we aimed to evaluate the clinical characteristics and the long-term clinical course of patients with BrS. Methods and results A total of 111 consecutive patients (86 males; aged 45.3 ± 13.3 years) diagnosed with BrS were included and followed-up in a prospective fashion. Thirty-seven patients (33.3%) were symptomatic at enrolment (arrhythmic syncope). An electrophysiological study (EPS) was performed in 59 patients (53.2%), and ventricular arrhythmias were induced in 32 (54.2%). A cardioverter defibrillator was implanted in 34 cases (30.6%). During a mean follow-up period of 4.6 ± 3.5 years, appropriate device therapies occurred in seven patients. Event-free survival analysis (log-rank test) showed that spontaneous type-1 electrocardiogram pattern (P = 0.008), symptoms at presentation (syncope) (P = 0.012), family history of sudden cardiac death (P < 0.001), positive EPS (P = 0.024), fragmented QRS (P = 0.004), and QRS duration in lead V2 > 113 ms (P < 0.001) are predictors of future arrhythmic events. Event rates were 0%, 4%, and 60% among patients with 0–1 risk factor, 2–3 risk factors, and 4–5 risk factors, respectively (P < 0.001). Current multiparametric score models exhibit an excellent negative predictive value and perform well in risk stratification of BrS patients. Conclusions Multiparametric models including common risk factors appear to provide better risk stratification of BrS patients than single factors alone.


Author(s):  
Anik Widjajanti ◽  
S.M. Agustini

A 7-year-old boy of Java origin, visited the doctor with progressive weakness everytime he ate food containing Monosodium Glutamat (MSG). Progressive weakness began from his legs and spreaded to the arms as well (sometimes also to the neck). He could neither walk nor do anything for 5–6 hours then began to resolve spontaneously.. We suspected the diagnosis of hypokalaemic periodic paralysis upon the history of episodes of flacid paralysis and low serum concentration of potassium (< 3,5 mmol/L) during the attacts. The clinical examination showed that this boy is in good general and nutritional conditions; electrocardiogram, laboratory blood count, urinalisis, thyroid, liver, kidney function, and ANA test were normal as well. The family history of flacid paralysis was negative. We have promptly administered potassium orally and his condition was improved progressively including less degree of flacid paralysis (the weakness). A genetic testing, electromyography (EMG), muscle biopsy and another examination has not performed.


2021 ◽  
Vol 22 (12) ◽  
pp. 6513
Author(s):  
Cristina Balla ◽  
Elena Conte ◽  
Rita Selvatici ◽  
Renè Massimiliano Marsano ◽  
Andrea Gerbino ◽  
...  

Background. Brugada syndrome (BrS) is an autosomal dominantly inherited cardiac disease characterized by “coved type” ST-segment elevation in the right precordial leads, high susceptibility to ventricular arrhythmia and a family history of sudden cardiac death. The SCN5A gene, encoding for the cardiac voltage-gated sodium channel Nav1.5, accounts for ~20–30% of BrS cases and is considered clinically relevant. Methods. Here, we describe the clinical findings of two Italian families affected by BrS and provide the functional characterization of two novel SCN5A mutations, the missense variant Pro1310Leu and the in-frame insertion Gly1687_Ile1688insGlyArg. Results. Despite being clinically different, both patients have a family history of sudden cardiac death and had history of arrhythmic events. The Pro1310Leu mutation significantly reduced peak sodium current density without affecting channel membrane localization. Changes in the gating properties of expressed Pro1310Leu channel likely account for the loss-of-function phenotype. On the other hand, Gly1687_Ile1688insGlyArg channel, identified in a female patient, yielded a nearly undetectable sodium current. Following mexiletine incubation, the Gly1687_Ile1688insGlyArg channel showed detectable, albeit very small, currents and biophysical properties similar to those of the Nav1.5 wild-type channel. Conclusions. Overall, our results suggest that the degree of loss-of-function shown by the two Nav1.5 mutant channels correlates with the aggressive clinical phenotype of the two probands. This genotype-phenotype correlation is fundamental to set out appropriate therapeutical intervention.


2010 ◽  
Vol 2010 ◽  
pp. 1-4
Author(s):  
Bronwyn Harris ◽  
Jean P. Pfotenhauer ◽  
Cheri A. Silverstein ◽  
Larry W. Markham ◽  
Kim Schafer ◽  
...  

Hypertrophic cardiomyopathy (HCM) is an inherited cardiac disease with an autosomal dominant mode of transmission. Comprehensive genetic screening of several genes frequently found mutated in HCM is recommended for first-degree relatives of HCM patients. Genetic testing provides the means to identify those at risk of developing HCM and to institute measures to prevent sudden cardiac death (SCD). Here, we present an adoptee whose natural mother and maternal relatives were known be afflicted with HCM and SCD. The proband was followed closely from age 6 to 17 years, revealing a natural history of the progression of clinical findings associated with HCM. Genetic testing of the proband and her natural mother, who is affected by HCM, revealed that they were heterozygous for both the R719Q and T1513S variants in the cardiac beta-myosin heavy chain (MYH7) gene. The proband's ominous family history indicates that the combination of the R719Q and T1513S variantsin cismay be a “malignant” variant that imparts a poor prognosis in terms of the disease progression and SCD risk.


2020 ◽  
Author(s):  
Leann A Lovejoy ◽  
Clesson E Turner ◽  
Craig D Shriver ◽  
Rachel E Ellsworth

Abstract Background The majority of active duty service women (ADS) are young, have access to healthcare, and meet fitness standards set by the U.S. military, suggesting that ADS represent a healthy population at low risk of cancer. Breast cancer is, however, the most common cancer in ADS and may have a significant effect on troop readiness with lengthy absence during treatment and inability to return to duty after the treatment. The identification of unaffected ADS who carry germline mutations in cancer predisposition genes (“previvors”) would provide the opportunity to prevent or detect cancer at an early stage, thus minimizing effects on troop readiness. In this study, we determined (1) how many high-risk ADS without cancer pursued genetic testing, (2) how many previvors employed risk-reducing strategies, and (3) the number of undiagnosed previvors within an ADS population. Methods The Clinical Breast Care Project (protocol WRNMMC IRB #20704) database of the Murtha Cancer Center/Walter Reed National Military Medical Center was queried to identify all ADS with no current or previous history of cancer. Classification as high genetic risk was calculated using National Comprehensive Cancer Network 2019 guidelines for genetic testing for breast, ovary, colon, and gastric cancer. The history of clinical genetic testing and risk-reducing strategies was extracted from the database. Genomic DNA from ADS with blood specimens available for research purposes were subjected to next-generation sequencing technologies using a cancer predisposition gene panel. Results Of the 336 cancer-free ADS enrolled in the Clinical Breast Care Project, 77 had a family history that met National Comprehensive Cancer Network criteria for genetic testing for BRCA1/2 and 2 had a family history of colon cancer meeting the criteria for genetic testing for Lynch syndrome. Of the 28 (35%) high-risk women who underwent clinical genetic testing, 11 had pathogenic mutations in the breast cancer genes BRCA1 (n = 5), BRCA2 (n = 5), or CHEK2 (n = 1). Five of the six ADS who had a relative with a known pathogenic mutation were carriers of the tested mutation. All of the women who had pathogenic mutations detected through clinical genetic testing underwent prophylactic double mastectomy, and three also had risk-reducing salpingo-oophorectomy. Two (6%) of the 33 high-risk ADS tested only in the research setting had a family history of breast/ovarian cancer and carried pathogenic mutations: one carried a BRCA2 mutation, whereas the other carried a mutation in the colon cancer predisposition gene PMS2. No mutations were detected in the 177 low-risk women tested in the research setting. Discussion Within this unaffected cohort of ADS, 23% were classified as high risk. Although all of the previvors engaged in risk-reduction strategies, only one-third of the high-risk women sought genetic testing. These data suggest that detailed family histories of cancer should be collected in ADS and genetic testing should be encouraged in those at high risk. The identification of previvors and concomitant use of risk-reduction strategies may improve health in the ADS and optimize military readiness by decreasing cancer incidence.


2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Hyo Geun Choi ◽  
Wook Chun ◽  
Kuk Hyun Jung

2014 ◽  
Vol 8 (11-12) ◽  
pp. 783 ◽  
Author(s):  
Richard Walker ◽  
Alyssa Louis ◽  
Alejandro Berlin ◽  
Sheri Horsburgh ◽  
Robert G. Bristow ◽  
...  

Introduction: The prostate-specific antigen (PSA) era and resultant early detection of prostate cancer has presented clinicians with the challenge of distinguishing indolent from aggressive tumours. Mutations in the BRCA1/2 genes have been associated with prostate cancer risk and prognosis. We describe the prostate cancer screening characteristics of BRCA1/2 mutation carriers, who may be classified as genetically-defined high risk, as compared to another high-risk cohort of men with a family history of prostate cancer to evaluate the utility of a targeted screening approach for these men.Methods: We reviewed patient demographics, clinical screening characteristics, pathological features, and treatment outcomes between a group of BRCA1 or BRCA2 mutation carriers and age-matched men with a family history of prostate cancer followed at our institutional Prostate Cancer Prevention Clinic from 1995 to 2012.Results: Screening characteristics were similar between the mutation carriers (n = 53) and the family history group (n = 53). Some cancers would be missed in both groups by using a PSA cut-off of >4 ug/L. While cancer detection was higher in the family history group (21% vs. 15%), the mutation carrier group was more likely to have intermediate- or high-risk disease (88% vs. 36%). BRCA2 mutation carriers were more likely to have aggressive disease, biological recurrence, and distant metastasis.Conclusions: In our cohort, regular screening appears justified for detecting prostate cancer in BRCA1 and BRCA2 carriers and other high-risk populations. Lowering PSA cut-offs and defining monitoring of PSA velocity as part of the screening protocol may be useful. BRCA2 is associated with more aggressive disease, while the outcome for BRCA1 mutation carriers requires further study. Large multinational studies will be important to define screening techniques for this unique high-risk population.


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