The genetic architecture of pediatric cardiomyopathy.

2022

2022 Jan 10

1537-6605

<p>To understand the genetic contribution to primary pediatric cardiomyopathy, we performed exome sequencing in a large cohort of 528 children with cardiomyopathy. Using clinical interpretation guidelines and targeting genes implicated in cardiomyopathy, we identified a genetic cause in 32% of affected individuals. Cardiomyopathy sub-phenotypes differed by ancestry, age at diagnosis, and family history. Infants &lt; 1 year were less likely to have a molecular diagnosis (p &lt; 0.001). Using a discovery set of 1,703 candidate genes and informatic tools, we identified rare and damaging variants in 56% of affected individuals. We see an excess burden of damaging variants in affected individuals as compared to two independent control sets, 1000 Genomes Project (p &lt; 0.001) and SPARK parental controls (p &lt; 1&nbsp;× 10). Cardiomyopathy variant burden remained enriched when stratified by ancestry, variant type, and sub-phenotype, emphasizing the importance of understanding the contribution of these factors to genetic architecture. Enrichment in this discovery candidate gene set suggests multigenic mechanisms underlie sub-phenotype-specific causes and presentations of cardiomyopathy. These results identify important information about the genetic architecture of pediatric cardiomyopathy and support recommendations for clinical genetic testing in children while illustrating differences in genetic architecture by age, ancestry, and sub-phenotype and providing rationale for larger studies to investigate multigenic contributions.</p>

10.1016/j.ajhg.2021.12.006

Am J Hum Genet

35026164

Impact of Genetic Testing for Cardiomyopathy on Emotional Well-Being and Family Dynamics: A Study of Parents and Adolescents.

2021

CIRCGEN120003189

2021 Jul 13

2574-8300

<p><strong>BACKGROUND: </strong>Genetic testing is indicated for children with a personal or family history of hereditary cardiomyopathy to determine appropriate management and inform risk stratification for family members. The implications of a positive genetic result for children can potentially impact emotional well-being. Given the nuances of cardiomyopathy genetic testing for minors, this study aimed to understand how parents involve their children in the testing process and investigate the impact of genetic results on family dynamics.</p>

<p><strong>METHODS: </strong>A survey was distributed to participants recruited from the Children's Cardiomyopathy Foundation and 7 North American sites in the Pediatric Cardiomyopathy Registry. The survey explored adolescent and parent participants' emotions upon receiving their/their child's genetic results, parent-child result communication and its impact on family functionality, using the McMaster Family Assessment Device.</p>

<p><strong>RESULTS: </strong>One hundred sixty-two parents of minors and 48 adolescents who were offered genetic testing for a personal or family history of cardiomyopathy completed the survey. Parents whose child had cardiomyopathy were more likely to disclose positive diagnostic genetic results to their child (=0.014). Parents with unaffected children and positive predictive testing results were more likely to experience negative emotions about the result (≤0.001) but also had better family functioning scores than those with negative predictive results (=0.019). Most adolescents preferred results communicated directly to the child, but parents were divided about whether their child's result should first be released to them or their child.</p>

<p><strong>CONCLUSIONS: </strong>These findings have important considerations for how providers structure genetic services for adolescents and facilitate discussion between parents and their children about results.</p>

10.1161/CIRCGEN.120.003189

Circ Genom Precis Med

34255550

Genetic Causes of Cardiomyopathy in Children: First Results From the Pediatric Cardiomyopathy Genes Study.

2021

e017731

2021 Apr 28

2047-9980

<p>Background Pediatric cardiomyopathy is a genetically heterogeneous disease with substantial morbidity and mortality. Current guidelines recommend genetic testing in children with hypertrophic, dilated, or restrictive cardiomyopathy, but practice variations exist. Robust data on clinical testing practices and diagnostic yield in children are lacking. This study aimed to identify the genetic causes of cardiomyopathy in children and to investigate clinical genetic testing practices. Methods and Results Children with familial or idiopathic cardiomyopathy were enrolled from 14 institutions in North America. Probands underwent exome sequencing. Rare sequence variants in 37 known cardiomyopathy genes were assessed for pathogenicity using consensus clinical interpretation guidelines. Of the 152 enrolled probands, 41% had a family history of cardiomyopathy. Of 81 (53%) who had undergone clinical genetic testing for cardiomyopathy before enrollment, 39 (48%) had a positive result. Genetic testing rates varied from 0% to 97% between sites. A positive family history and hypertrophic cardiomyopathy subtype were associated with increased likelihood of genetic testing (=0.005 and =0.03, respectively). A molecular cause was identified in an additional 21% of the 63 children who did not undergo clinical testing, with positive results identified in both familial and idiopathic cases and across all phenotypic subtypes. Conclusions A definitive molecular genetic diagnosis can be made in a substantial proportion of children for whom the cause and heritable nature of their cardiomyopathy was previously unknown. Practice variations in genetic testing are great and should be reduced. Improvements can be made in comprehensive cardiac screening and predictive genetic testing in first-degree relatives. Overall, our results support use of routine genetic testing in cases of both familial and idiopathic cardiomyopathy. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01873963.</p>

10.1161/JAHA.120.017731

J Am Heart Assoc

33906374

Cardiac Biomarkers in Pediatric Cardiomyopathy: Study Design and Recruitment Results from the Pediatric Cardiomyopathy Registry.

2019

1-10

2019 Jun

1058-9813

<p><strong>Background: </strong>Cardiomyopathies are a rare cause of pediatric heart disease, but they are one of the leading causes of heart failure admissions, sudden death, and need for heart transplant in childhood. Reports from the Pediatric Cardiomyopathy Registry (PCMR) have shown that almost 40% of children presenting with symptomatic cardiomyopathy either die or undergo heart transplant within 2 years of presentation. Little is known regarding circulating biomarkers as predictors of outcome in pediatric cardiomyopathy.</p>

<p><strong>Study Design: </strong>The Cardiac Biomarkers in Pediatric Cardiomyopathy (PCM Biomarkers) study is a multi-center prospective study conducted by the PCMR investigators to identify serum biomarkers for predicting outcome in children with dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). Patients less than 21 years of age with either DCM or HCM were eligible. Those with DCM were enrolled into cohorts based on time from cardiomyopathy diagnosis: categorized as new onset or chronic. Clinical endpoints included sudden death and progressive heart failure.</p>

<p><strong>Results: </strong>There were 288 children diagnosed at a mean age of 7.2±6.3 years who enrolled in the PCM Biomarkers Study at a median time from diagnosis to enrollment of 1.9 years. There were 80 children enrolled in the new onset DCM cohort, defined as diagnosis at or 12 months prior to enrollment. The median age at diagnosis for the new onset DCM was 1.7 years and median time from diagnosis to enrollment was 0.1 years. There were 141 children enrolled with either chronic DCM or chronic HCM, defined as children ≥2 years from diagnosis to enrollment. Among children with chronic cardiomyopathy, median age at diagnosis was 3.4 years and median time from diagnosis to enrollment was 4.8 years.</p>

<p><strong>Conclusion: </strong>The PCM Biomarkers study is evaluating the predictive value of serum biomarkers to aid in the prognosis and management of children with DCM and HCM. The results will provide valuable information where data are lacking in children.</p>

<p><strong>Clinical Trial Registration NCT01873976: </strong>https://clinicaltrials.gov/ct2/show/NCT01873976?term=PCM+Biomarker&amp;…;

10.1016/j.ppedcard.2019.02.004

Prog. Pediatr. Cardiol.

31745384

No Obesity Paradox in Pediatric Patients With Dilated Cardiomyopathy.

2018

222-230

2018 Mar

2213-1787

<p><strong>OBJECTIVES: </strong>This study aimed to examine the role of nutrition in pediatric dilated cardiomyopathy (DCM).</p>

<p><strong>BACKGROUND: </strong>In adults with DCM, malnutrition is associated with mortality, whereas obesity is associated with survival.</p>

<p><strong>METHODS: </strong>The National Heart, Lung, and Blood Institute-funded Pediatric Cardiomyopathy Registry was used to identify patients with DCM and categorized by anthropometric measurements: malnourished (MN) (body mass index [BMI]&nbsp;&lt;5% for&nbsp;≥2 years or weight-for-length&nbsp;&lt;5% for&nbsp;&lt;2 years), obesity (BMI &gt;95% for age&nbsp;≥2 years or weight-for-length &gt;95% for&nbsp;&lt;2 years), or normal bodyweight (NB). Of 904 patients with DCM, 23.7% (214) were MN, 13.3% (120) were obese, and 63.1% (570) were NB.</p>

<p><strong>RESULTS: </strong>Obese patients were older (9.0 vs. 5.7 years for NB; p&nbsp;&lt; 0.001) and more likely to have a family history of DCM (36.1% vs. 23.5% for NB; p&nbsp;= 0.023). MN patients were younger (2.7 years vs. 5.7 years for NB; p&nbsp;&lt; 0.001) and more likely to have heart failure (79.9% vs. 69.7% for NB; p&nbsp;= 0.012), cardiac dimension z-scores &gt;2, and higher ventricular mass compared with NB. In multivariable analysis, MN was associated with increased risk of death (hazard&nbsp;ratio [HR]: 2.06; 95% confidence interval [CI]: 1.66 to 3.65; p&nbsp;&lt; 0.001); whereas obesity was not (HR: 1.49; 95% CI: 0.72 to 3.08). Competing outcomes analysis demonstrated increased risk of mortality for MN compared with NB (p&nbsp;=&nbsp;0.03), but no difference in transplant rate (p&nbsp;= 0.159).</p>

<p><strong>CONCLUSIONS: </strong>Malnutrition is associated with increased mortality and other unfavorable echocardiographic and clinical&nbsp;outcomes compared with those of NB. The same effect of obesity on survival was not observed. Further studies are needed investigating the long-term impact of abnormal anthropometric measurements on outcomes in pediatric DCM. (Pediatric&nbsp;Cardiomyopathy Registry; NCT00005391).</p>

10.1016/j.jchf.2017.11.015

JACC Heart Fail

29428438

Pediatric Cardiomyopathies.

2017

855-873

2017 Sep 15

1524-4571

<p>Pediatric cardiomyopathies are rare diseases with an annual incidence of 1.1 to 1.5 per 100 000. Dilated and hypertrophic cardiomyopathies are the most common; restrictive, noncompaction, and mixed cardiomyopathies occur infrequently; and arrhythmogenic right ventricular cardiomyopathy is rare. Pediatric cardiomyopathies can result from coronary artery abnormalities, tachyarrhythmias, exposure to infection or toxins, or secondary to other underlying disorders. Increasingly, the importance of genetic mutations in the pathogenesis of isolated or syndromic pediatric cardiomyopathies is becoming apparent. Pediatric cardiomyopathies often occur in the absence of comorbidities, such as atherosclerosis, hypertension, renal dysfunction, and diabetes mellitus; as a result, they offer insights into the primary pathogenesis of myocardial dysfunction. Large international registries have characterized the epidemiology, cause, and outcomes of pediatric cardiomyopathies. Although adult and pediatric cardiomyopathies have similar morphological and clinical manifestations, their outcomes differ significantly. Within 2 years of presentation, normalization of function occurs in 20% of children with dilated cardiomyopathy, and 40% die or undergo transplantation. Infants with hypertrophic cardiomyopathy have a 2-year mortality of 30%, whereas death is rare in older children. Sudden death is rare. Molecular evidence indicates that gene expression differs between adult and pediatric cardiomyopathies, suggesting that treatment response may differ as well. Clinical trials to support evidence-based treatments and the development of disease-specific therapies for pediatric cardiomyopathies are in their infancy. This compendium summarizes current knowledge of the genetic and molecular origins, clinical course, and outcomes of the most common phenotypic presentations of pediatric cardiomyopathies and highlights key areas where additional research is required.</p>

<p><strong>CLINICAL TRIAL REGISTRATION: </strong>URL: http://www.clinicaltrials.gov. Unique identifiers: NCT02549664 and NCT01912534.</p>

10.1161/CIRCRESAHA.116.309386

Circ. Res.

28912187