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Epigenetic changes are among the most common alterations observed in cancer cells, yet the mechanism by which cancer cells acquire and maintain abnormal DNA methylation patterns is not understood. Cancer cells have an altered distribution of DNA methylation and express aberrant DNA methyltransferase 3B transcripts, which encode truncated proteins, some of which lack the COOH-terminal catalytic domain. To test if a truncated DNMT3B isoform disrupts DNA methylation in vivo, we constructed two lines of transgenic mice expressing DNMT3B7, a truncated DNMT3B isoform commonly found in cancer cells. DNMT3B7 transgenic mice exhibit altered embryonic development, including lymphopenia, craniofacial abnormalities, and cardiac defects, similar to Dnmt3b-deficient animals, but rarely develop cancer. However, when DNMT3B7 transgenic mice are bred with Eμ-Myc transgenic mice, which model aggressive B-cell lymphoma, DNMT3B7 expression increases the frequency of mediastinal lymphomas in Eμ-Myc animals. Eμ-Myc/DNMT3B7 mediastinal lymphomas have more chromosomal rearrangements, increased global DNA methylation levels, and more locus-specific perturbations in DNA methylation patterns compared with Eμ-Myc lymphomas. These data represent the first in vivo modeling of cancer-associated DNA methylation changes and suggest that truncated DNMT3B isoforms contribute to the redistribution of DNA methylation characterizing virtually every human tumor. Cancer Res; 70(14); 5840–50. ©2010 AACR.

Supplementary Methods, Figures 1-10, Tables 1-8 from DNMT3B7, a Truncated DNMT3B Isoform Expressed in Human Tumors, Disrupts Embryonic Development and Accelerates Lymphomagenesis

Dystrophin deficiency results in cardiomyopathy and fibrosis with variable onset. Little is known about electrocardiographic abnormalities in Becker muscular dystrophy and their relationship to underlying cardiac pathology. We hypothesized QRS fragmentation is associated with myocardial fibrosis on cardiac magnetic resonance imaging in Becker muscular dystrophy patients. We retrospectively evaluated 44 patients, and extracted data from clinically obtained electrocardiogram and cardiac magnetic resonance. Ventricular function and presence or absence late gadolinium enhancement representing myocardial fibrosis were recorded from imaging. Nearly half (19/42, 45%) of patients interrogated had myocardial fibrosis on cardiac magnetic resonance. Total number of electrocardiogram leads with QRS fragmentation (median 1 vs 4, p 0.001) and either right or left axis deviation from median was significantly increased (13.6 vs. 44.8°, p 0.001) in patients with myocardial fibrosis. Decreased leftward voltage in V6 correlated to both increased fibrosis and decreased cardiac function (p 0.01). The positive likelihood ratio for underlying myocardial fibrosis in patients with two of the three findings on electrocardiogram was 8.47 (p 0.0001). QRS fragmentation and axis deviation on electrocardiography are strongly predictive of myocardial fibrosis in Becker muscular dystrophy and may inform the use of advanced imaging in evaluation of these patients.

Background Ablation of atrial tachyarrhythmia in adults with congenital heart disease (ACHD) is challenging because of complex anatomy and high scar burden. We proposed that the addition of high-density mapping with the PentaRay® (Biosense Webster, Inc) mapping catheter (EAM+P) to 3-dimensional electroanatomic mapping (EAM) allows for rapid acquisition of high-resolution maps and shorter procedure times. Methods In this single-center, retrospective cohort study of patients with ACHD who underwent atrial arrhythmia ablation, patients were divided those who underwent ablation with EAM and those who underwent ablation with EAM+P. Results Fifteen ablations were performed in 13 patients using standard EAM, and 11 ablations were performed in 10 patients using EAM+P. There was no difference in mean age or complexity of congenital heart disease. The procedure duration was 1.5 times longer in the EAM than in the EAM+P group (P = .015). The dose area product was 12 times higher in the EAM than in the EAM+P group (P = .001). A higher number of venous access sites were used for EAM cases than for EAM+P cases (P = .008). Acute success rates of ablation and recurrence rates at 1 year were similar in the 2 groups. There were no procedure-related complications in either group. Conclusion This is the first study to evaluate the use of the PentaRay® high-density mapping catheter for ablation of atrial tachyarrhythmia in patients with ACHD. The use of the PentaRay® high-density mapping catheter results in shorter procedure time, decreased radiation exposure, and fewer venous access sites.

The standard technique for accessory pathway ablation involves mapping along the mitral and tricuspid annulus to localize the regions of earliest ventricular activation during antegrade pathway conduction, earliest atrial activation during retrograde conduction or detection of an accessory pathway potential. In some cases despite what appears to be appropriate mapping, catheter positioning and adequate power delivery the ablation is not successful. In many of these cases, the pathway is felt to be inaccessible because of a location remote from the mitral or tricuspid annulus that cannot be affected by endocardial power delivery along the annulus. In the case of difficult left sided pathways, some may be reached and ablated via the coronary sinus or its branches. Right sided pathways cannot be approached in this fashion since there is no venous structure analogous to the coronary sinus around the tricuspid annulus. Alternative mapping and ablation techniques for these difficult pathways have included epicardial mapping via direct pericardial access or attempts to localize pathway insertion areas remote from the valve annulus which may be amenable to endocardial ablation. We describe the use of post-pacing interval mapping to localize the atrial input of a right sided antegrade only accessory pathway that was resistant to conventional mapping and ablation strategies.

Introduction: Slow pathway (SP) modification via cryoablation is a common treatment of atrioventricular nodal reentrant tachycardia (AVNRT) in pediatric patients. Traditionally, SP modification was achieved by anatomical landmarks, ideal electrogram characteristics, or low voltage bridge mapping. Recently, sinus propagation mapping (SPM) is a tool that has been used to augment identification of the SP. We hypothesize that the use of SPM will decrease the total number of ablations performed and decrease the number of ablations until the SP was successfully modified without a significant increase in procedure time. Methods: We conducted a retrospective review of patients who underwent cryoablation for AVNRT from August 2016 through March 2021. There were no other technological or procedural changes during the study period besides the addition of SPM. We excluded patients greater than 21 years of age, the use of radiofrequency ablation, prior AVNRT ablation, additional pathways or arrhythmias, and those with congenital heart disease. Patients were divided into two groups: those who did and did not undergo SPM. Mann-Whitney U tests were utilized to compare significance between the two groups. Results: Out of 122 patients identified by IMPACT database query, 103 met inclusion criteria. Fifty-two patients (50.5%) had SPM completed during their procedures. Age, weight, and BSA were not statistically different between the groups. Ablation was acutely successful in all but two patients, both in the non-SPM group. The median number of ablations needed until successful SP modification was 2 in patients who underwent SPM, and 4 in the non-SPM group (p = 0.03). There was no significant difference between total number of ablations between groups. The median total procedural time was longer in the SPM group (152 vs 125 min, p = 0.01). There was no difference in clinical recurrence or complications between the two groups. Conclusions: Sinus propagation mapping can be utilized to further improve the successful treatment of AVNRT with cryotherapy by lowering the number of ablations needed until successful SP modification. However, the technique requires some additional time to collect sufficient data points to create the sinus map.

Background Rhythm disorders are the leading cause of morbidity and mortality in adults with congenital heart disease (ACHD). Infrequent or asymptomatic arrhythmias may not be detected by routine monitoring. Implantable loop recorders (ILRs), such as the Reveal LINQTM , have been useful in long-term monitoring for arrhythmias in adults with cryptogenic stroke. Objective We propose the Reveal LINQTM will detect arrhythmias, not documented by other monitoring modalities, resulting in change in management in ACHD patients. Methods This is a single center retrospective review of Reveal LINQTM use in ACHD patients from 2014-2017. Medical records were reviewed to determine cardiac diagnosis, indication for implant, ILR findings, and changes in management. Results Twenty-two patients, median age 25 years, underwent ILR implantation. ILR findings resulted in change in management in nine (41%) patients. One-third (3/9) of the patients with clinically relevant events were asymptomatic. Patients with Fontan palliation had the highest number of pertinent positive events (57%). ACHD physiologic class D patients were more likely to have a positive finding (P = .034) compared to other physiologic classes. Majority (75%) of patients with positive events had arrhythmias documented on ILR which were not demonstrated on prior Holter/event monitors. Pertinent negative event occurred in one patient with Fontan palliation (5%) who had syncope corresponding to sinus rhythm. Conclusion ILRs are a useful adjunct for arrhythmia monitoring in the ACHD population with clinically relevant events in 41% of patients. A special consideration for ILRs could be made for high-risk asymptomatic patients.

Introduction: After the initial surgical repair of tetralogy of Fallot (rTOF), right ventricular outflow tract dysfunction is common, with pulmonary stenosis (PS), regurgitation, or both. Obese adults with rTOF have worse biventricular systolic function, and greater post-operative pulmonary valve replacement morbidity than non-obese patients. Transcatheter PVR (TPVR) is used increasingly, though no studies have examined the impact of body mass index (BMI) on morbidity and hemodynamics in adults with rTOF and subsequent TPVR. Hypothesis: BMI affects outcomes of transcatheter PVR in adults with TOF. Methods: This was a 10 yr, single center, retrospective review of adults (>18 yo) with rTOF who underwent TPVR. The cohort was split into 2 groups based on BMI at time of TPVR. Group A (Grp A): normal and overweight (BMI Results: There were 81 adults, 42 (52%) normal, 18 (22%) overweight (Grp A) and 21 (26%) obese (Grp B). Mean follow up was 6.4 + 3.1 yrs. With most recent post-TPVR echocardiogram, there was no significant difference in LV or RV size and function across groups. Compared to Grp A, Grp B patients were more likely to develop any degree of PS (mild, moderate, or severe) following TPVR (69% vs 94%, respectively, p = 0.032). An ROC curve analysis demonstrated BMI ≥ 26.3 had a low sensitivity (45%), but good specificity (89%) for predicting PS post TPVR. There was no difference between groups requiring re- intervention for PVR. Conclusion: This is the first study to show greater BMI affects valve function in adults with rTOF following TPVR. BMI >26 was associated with a greater risk of PS in follow up echocardiograms after TPVR. Obesity is an epidemic in the US and patient prosthesis mismatch may be an issue when considering TPVR. Further studies are indicated to determine the long-term effects of BMI on TPVR and the need for re-intervention in adults with TOF.

Supraventricular tachycardia (SVT) is the most common sustained arrhythmia in children. Infants with SVT and ventricular preexcitation (Wolff-Parkinson-White syndrome) are known to have up to 30% prevalence of congenital heart disease (CHD). Infants without ventricular preexcitation who present with SVT at1 year of age have a similar prevalence of CHD. However, for children without ventricular preexcitation who present with SVT at older ages, the prevalence of CHD is not known. The aim of this study was to determine the prevalence of CHD in older children and adolescents presenting with SVT without ventricular preexcitation, with the goal of providing guidance regarding the usefulness of echocardiography in this patient population.Children aged 2 to 18 years presenting with confirmed SVT between January 2011 and December 2015 were included in this retrospective review. Patients with any history of ventricular preexcitation or preexisting heart disease were excluded. Medical records were reviewed, and electrocardiographic and echocardiographic findings were classified as normal, incidental, or abnormal.Two hundred ninety patients met the inclusion criteria. Echocardiographic examinations were completed on 224 patients. Only one patient was found to have CHD, a moderate primum atrial septal defect. This patient was noted to have electrocardiographic abnormalities consistent with primum atrial septal defect.For older children and adolescents with no known heart disease presenting with SVT without ventricular preexcitation, echocardiography may not be a necessary part of initial evaluation when the results of physical examination and electrocardiography are normal.

Genetic testing is important to augment clinical diagnosis and inform management of inherited arrhythmias syndromes (IAS), but variants of uncertain significance (VUS) are common and remain a challenge in clinical practice. In 2015, American College of Medical Genetics (ACMG) published updated guidelines for interpretation of genetic results. Despite increasing understanding of human genomic variation, there are no guidelines for reinterpretation of prior genetic test results. Patients at a single tertiary children's hospital with genetic testing for an IAS that demonstrated a VUS were re-evaluated using 2015 ACMG guidelines, clinical information, and publically available databases. Search of the electronic medical record identified 116 patients with genetic testing results available, and 24/116 (21%) harbored a VUS for an IAS. 23 unique VUS were evaluated from 12 genes. Over half of the VUS (12/23 (52%)) were reclassified using 2015 criteria, and 8 (35%) changed to pathogenic and 4 (17%) to benign. Relative risk of reclassification of VUS to a pathogenic variant in a patient with confirmed clinical diagnosis was 4.1 (95% CI 1.23-15.4). Reclassification was not associated with initial testing year. These data demonstrate 52% of VUS in children with IAS are reclassified with application of 2015 ACMG guidelines. Strength of phenotyping is associated with eventual pathogenic classification of genetic variants and periodic re-evaluation of VUS identified on genetic testing for IAS is warranted.

Adult literature has established a link between premature ventricular contraction (PVC) burden as low as 10% on 24 hour Holter monitor and cardiac dysfunction requiring monitoring and treatment to prevent cardiomyopathy. Frequent PVCs are common in the pediatric population. However, the impact of

Duchenne muscular dystrophy (DMD) is an X-linked results in dystrophin deficiency and universally develop cardiomyopathy and early mortality. Subepicardial myocardial fibrosis (MF) by late gadolinium enhancement (LGE) precedes decline in left ventricular ejection fraction (LVEF) by cardiac magnetic

Background Many patients with congenital heart disease (CHD) acquire rhythm abnormalities related to their repair, most commonly intraatrial reentrant tachycardia (IART). Treatment of IART in CHD is often multifaceted, and may include medication, ablation, and pacing. Evidence regarding the use of antitachycardia pacing therapies is limited. Objective The aim of the study is to define the use and efficacy of antitachycardia pacing in patients with CHD at a single center. Results Eighty implants were performed on 72 patients between 2000 and 2010. Follow-up data of more than 3 months were available for 56 patients; median follow-up time was 2.8 years. Twenty (36%) patients received successful antitachycardia pacing at a median 1.3 years postimplant. For those patients with IART after implant, antitachycardia pacing was successful in 57%. Patients with two-ventricle repairs were more likely to have successful antitachycardia pacing than those with one-ventricle palliation (45% vs. 17%, P = .04). Patients with documented IART had more successful antitachycardia pacing than those with no documented atrial tachycardia prior to implant (46% vs. 7%, P = .006). Early complications of antitachycardia pacemaker implant occurred in six patients (11%); late complications after implant occurred in three patients (5.6%). Of the initial 72 patients implanted, there were six deaths (8%). Conclusions Antitachycardia pacing therapies were successful in the majority of CHD patients who had IART after implant. Patients without documented atrial tachycardia prior to implant were unlikely to require or receive successful therapy from antitachycardia pacemaker. Those patients postatrial switch procedure who had documented IART prior to implant had the highest incidence of successful antitachycardia pacing therapies. Antitachycardia pacemaker implantation is an adjunct to the management of IART in CHD patients, but may not benefit patients who have not yet demonstrated IART.

Background Recent studies suggest that Doppler echocardiography (DE)-based estimates of pulmonary artery systolic pressure (PASP) may not be as accurate as previously believed. We sought to determine the accuracy of PASP measurements using DE compared with right-sided heart catheterization (RHC) in patients with pulmonary hypertension (PH). Methods We compared DE estimates of PASP to invasively measure PASP during RHC in 160 consecutive patients with PH (part one). To account for possible changes in hemodynamics between DE and RHC, we then prospectively determined PASP in an additional 23 consecutive patients undergoing simultaneous RHC and DE (part two). Bland-Altman analyses were performed to evaluate the agreement between RHC and DE measurements of PASP. Accuracy was predefined as 95% limits of agreement within ± 10 mm Hg for PASP estimates. Results In part one, there was moderate correlation between DE and RHC measurements of PASP (r = 0.68, P Conclusions DE estimates of PASP are inaccurate in patients with PH and should not be relied on to make the diagnosis of PH or to follow the efficacy of therapy.

Empirical evidence supporting a genetic basis for the etiology of congenital heart disease (CHD) is limited and few disease-causing mutations have been identified. To identify novel CHD genes, we performed a forward genetic screen to identify mutant mouse lines with heritable CHD. Lines with recessive N-ethyl-N-nitrsourea-induced CHD-causing mutations were identified using a three-generation backcross. A hierarchical screening protocol was used to test the hypothesis that the fetal-to-neonatal circulatory transition unmasks the specific structural heart defects observed in CHD. Mice with heart defects were efficiently ascertained by selecting for pups exhibiting perinatal lethality and characterizing their cardiac pathology. A marked increase of perinatal lethality was observed in the mutagen-treated cohort compared with an untreated backcross population. Cardiac pathology on perinatal lethals revealed cardiovascular defects in 79 pups from 47 of 321 mutagenized lines. All identified structural abnormalities were analogous to previously described forms of human CHD. Furthermore, the phenotypic recurrence and variance patterns across all lines were similar to human CHD prevalence and recurrence patterns. We mapped the locus responsible for heritable atrioventricular septal defects in six lines (avc1-6). Our screen demonstrated that 'sporadic' CHD may have major genetic component and established a practical, efficient approach for identifying CHD candidate genes.

Aims Patients with D-loop transposition of the great arteries (D-TGA) status post intra-atrial baffling are at an increased risk for sudden cardiac arrest. The benefit of primary implantable cardioverter-defibrillator (ICD) implantation in these patients is questionable due to high burden of adverse events. We aimed to evaluate the incidence and causes of all types of device shocks, as well as of device-related complications among patients with D-TGA implanted with ICDs for primary prevention. Methods and results Retrospective analysis of all patients with D-TGA who underwent atrial switch procedure and ICD implantation for primary prevention. Eighteen patients (83% males) were identified. Average age at atrial switch was 2.5 years (range 0.1–17) and at ICD implantation 26 years (15–41). During a median follow-up of 4 years, 10 patients (55%) received shocks for non-ventricular arrhythmic events, whereas 1 patient was shocked for ventricular tachycardia, for an annual rate of shock delivery of 7.1%. The most common cause for shock delivery was the occurrence of atrial arrhythmias, mostly in the form of atrial flutter. Elevated systemic ventricular end-diastolic pressures were found to be associated with an increased risk for inappropriate shocks. Five patients (28%) required lead extraction and three required generator change due to device recalls during follow-up. Conclusion Atrial arrhythmias were the most common cause for ICD shocks in a primary prevention population, while ventricular tachycardia was infrequent. The association between elevated end-diastolic pressures and the occurrence of arrhythmias demonstrates the close mechano-electrical relationship in D-TGA and may be an important predictor of arrhythmic events.

Cardiac left ventricular outflow tract (LVOT) defects represent a common but heterogeneous subset of congenital heart disease for which gene identification has been difficult. We describe a 46,XY,t(1;5)(p36.11;q31.2)dn translocation carrier with pervasive developmental delay who also exhibited LVOT defects, including bicuspid aortic valve (BAV), coarctation of the aorta (CoA) and patent ductus arteriosus (PDA). The 1p breakpoint disrupts the 5' UTR of AHDC1, which encodes AT-hook DNA-binding motif containing-1 protein, and AHDC1-truncating mutations have recently been described in a syndrome that includes developmental delay, but not congenital heart disease [Xia, F., Bainbridge, M.N., Tan, T.Y., Wangler, M.F., Scheuerle, A.E., Zackai, E.H., Harr, M.H., Sutton, V.R., Nalam, R.L., Zhu, W. et al. (2014) De Novo truncating mutations in AHDC1 in individuals with syndromic expressive language delay, hypotonia, and sleep apnea. Am. J. Hum. Genet., 94, 784-789]. On the other hand, the 5q translocation breakpoint disrupts the 3' UTR of MATR3, which encodes the nuclear matrix protein Matrin 3, and mouse Matr3 is strongly expressed in neural crest, developing heart and great vessels, whereas Ahdc1 is not. To further establish MATR3 3' UTR disruption as the cause of the proband's LVOT defects, we prepared a mouse Matr3(Gt-ex13) gene trap allele that disrupted the 3' portion of the gene. Matr3(Gt-ex13) homozygotes are early embryo lethal, but Matr3(Gt-ex13) heterozygotes exhibit incompletely penetrant BAV, CoA and PDA phenotypes similar to those in the human proband, as well as ventricular septal defect (VSD) and double-outlet right ventricle (DORV). Both the human MATR3 translocation breakpoint and the mouse Matr3(Gt-ex13) gene trap insertion disturb the polyadenylation of MATR3 transcripts and alter Matrin 3 protein expression, quantitatively or qualitatively. Thus, subtle perturbations in Matrin 3 expression appear to cause similar LVOT defects in human and mouse.

Complete atrioventricular (AV) block is defined as interruption in the transmission of the cardiac impulse from the atria to the ventricles due to an anatomical or functional impairment in the AV conduction system. The conduction disturbance can be transient or permanent.

The atrioventricular (AV) node is a complex structure. Anatomic descriptions of the AV node remain a subject of debate and significant gaps remain in the understanding of AV node physiology, despite the increased evidence with molecular data. Despite these gaps, there are clinically distinct patterns of abnormal AV nodal conduction that provide insight to pathologic mechanisms. Recognition of these patterns, and the natural history associated with each, is crucial for appropriate patient management.

Atrioventricular septal defects (AVSDs) are a common severe form of congenital heart disease (CHD). In this study we identified deleterious non-synonymous mutations in two cilia genes, Dnah11 and Mks1, in independent N-ethyl-N-nitrosourea-induced mouse mutant lines with heritable recessive AVSDs by whole-exome sequencing. Cilia are required for left/right body axis determination and second heart field (SHF) Hedgehog (Hh) signaling, and we find that cilia mutations affect these requirements differentially. Dnah11avc4 did not disrupt SHF Hh signaling and caused AVSDs only concurrently with heterotaxy, a left/right axis abnormality. In contrast, Mks1avc6 disrupted SHF Hh signaling and caused AVSDs without heterotaxy. We performed unbiased whole-genome SHF transcriptional profiling and found that cilia motility genes were not expressed in the SHF whereas cilia structural and signaling genes were highly expressed. SHF cilia gene expression predicted the phenotypic concordance between AVSDs and heterotaxy in mice and humans with cilia gene mutations. A two-step model of cilia action accurately predicted the AVSD/heterotaxyu phenotypic expression pattern caused by cilia gene mutations. We speculate that cilia gene mutations contribute to both syndromic and non-syndromic AVSDs in humans and provide a model that predicts the phenotypic consequences of specific cilia gene mutations.

Recent studies suggest that Doppler echocardiography (DE)-based estimates of pulmonary artery systolic pressure (PASP) may not be as accurate as previously believed. We sought to determine the accuracy of PASP measurements using DE compared with right-sided heart catheterization (RHC) in patients with pulmonary hypertension (PH).We compared DE estimates of PASP to invasively measure PASP during RHC in 160 consecutive patients with PH (part one). To account for possible changes in hemodynamics between DE and RHC, we then prospectively determined PASP in an additional 23 consecutive patients undergoing simultaneous RHC and DE (part two). Bland-Altman analyses were performed to evaluate the agreement between RHC and DE measurements of PASP. Accuracy was predefined as 95% limits of agreement within ± 10 mm Hg for PASP estimates.In part one, there was moderate correlation between DE and RHC measurements of PASP (r = 0.68, P.001). However, using Bland-Altman analysis, the bias for DE estimates of PASP was 2.2 mm Hg with 95% limits of agreement ranging from -34.2 to 38.6 mm Hg. DE estimates of PASP were determined to be inaccurate in 50.6% of patients. In part two, there was moderate correlation between DE and RHC measurements of PASP (r = 0.71, P.01). However, despite simultaneous DE and RHC measurements, the bias for DE estimates of PASP was 8.0 mm Hg with 95% limits of agreement ranging from -28.4 to 44.4 mm Hg.DE estimates of PASP are inaccurate in patients with PH and should not be relied on to make the diagnosis of PH or to follow the efficacy of therapy.

Epigenetic changes are among the most common alterations observed in cancer cells, yet the mechanism by which cancer cells acquire and maintain abnormal DNA methylation patterns is not understood. Cancer cells have an altered distribution of DNA methylation and express aberrant DNA methyltransferase 3B transcripts, which encode truncated proteins, some of which lack the COOH-terminal catalytic domain. To test if a truncated DNMT3B isoform disrupts DNA methylation in vivo, we constructed two lines of transgenic mice expressing DNMT3B7, a truncated DNMT3B isoform commonly found in cancer cells. DNMT3B7 transgenic mice exhibit altered embryonic development, including lymphopenia, craniofacial abnormalities, and cardiac defects, similar to Dnmt3b-deficient animals, but rarely develop cancer. However, when DNMT3B7 transgenic mice are bred with Eμ-Myc transgenic mice, which model aggressive B-cell lymphoma, DNMT3B7 expression increases the frequency of mediastinal lymphomas in Eμ-Myc animals. Eμ-Myc/DNMT3B7 mediastinal lymphomas have more chromosomal rearrangements, increased global DNA methylation levels, and more locus-specific perturbations in DNA methylation patterns compared with Eμ-Myc lymphomas. These data represent the first in vivo modeling of cancer-associated DNA methylation changes and suggest that truncated DNMT3B isoforms contribute to the redistribution of DNA methylation characterizing virtually every human tumor. Cancer Res; 70(14); 5840–50. ©2010 AACR.

BACKGROUND: Children with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for sudden death, and a risk stratification tool does not exist. OBJECTIVE: The purpose of this study was to determine whether proband status, age at symptom onset, and/or sex are independent predictors of cardiac events. METHODS: A multicenter, ambispective, cohort of pediatric CPVT patients was categorized by sex, proband status, and age at symptom onset (D1: first decade of life [symptom onset