Summary Noonan syndrome is a genetic multisystem disorder characterised by distinctive facial features, developmental delay, learning difficulties, short stature, congenital heart disease, renal ...anomalies, lymphatic malformations, and bleeding difficulties. Mutations that cause Noonan syndrome alter genes encoding proteins with roles in the RAS–MAPK pathway, leading to pathway dysregulation. Management guidelines have been developed. Several clinically relevant genotype–phenotype correlations aid risk assessment and patient management. Increased understanding of the pathophysiology of the disease could help development of pharmacogenetic treatments.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The Pediatric Cardiac Genomics Consortium (PCGC) designed the Congenital Heart Disease Genetic Network Study to provide phenotype and genotype data for a large congenital heart defects (CHDs) cohort. ...This article describes the PCGC cohort, overall and by major types of CHDs (e.g., conotruncal defects) and subtypes of conotrucal heart defects (e.g., tetralogy of Fallot) and left ventricular outflow tract obstructions (e.g., hypoplastic left heart syndrome). Cases with CHDs were recruited through ten sites, 2010-2014. Information on cases (N = 9,727) and their parents was collected through interviews and medical record abstraction. Four case characteristics, eleven parental characteristics, and thirteen parent-reported neurodevelopment outcomes were summarized using counts and frequencies and compared across CHD types and subtypes. Eleven percent of cases had a genetic diagnosis. Among cases without a genetic diagnosis, the majority had conotruncal heart defects (40%) or left ventricular outflow tract obstruction (21%). Across CHD types, there were significant differences (p<0.05) in the distribution of all four case characteristics (e.g., sex), four parental characteristics (e.g., maternal pregestational diabetes), and five neurodevelopmental outcomes (e.g., learning disabilities). Several characteristics (e.g., sex) were also significantly different across CHD subtypes. The PCGC cohort is one of the largest CHD cohorts available for the study of genetic determinants of risk and outcomes. The majority of cases do not have a genetic diagnosis. This description of the PCGC cohort, including differences across CHD types and subtypes, provides a reference work for investigators who are interested in collaborating with or using publically available resources from the PCGC.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Noonan syndrome (NS) is a common, clinically and genetically heterogeneous condition characterized by distinctive facial features, short stature, chest deformity, congenital heart disease, and other ...comorbidities. Gene mutations identified in individuals with the NS phenotype are involved in the Ras/MAPK (mitogen-activated protein kinase) signal transduction pathway and currently explain ∼61% of NS cases. Thus, NS frequently remains a clinical diagnosis. Because of the variability in presentation and the need for multidisciplinary care, it is essential that the condition be identified and managed comprehensively. The Noonan Syndrome Support Group (NSSG) is a nonprofit organization committed to providing support, current information, and understanding to those affected by NS. The NSSG convened a conference of health care providers, all involved in various aspects of NS, to develop these guidelines for use by pediatricians in the diagnosis and management of individuals with NS and to provide updated genetic findings.
Tendons and ligaments are fibrous connective tissues vital to the transmission of force and stabilization of the musculoskeletal system. Arising in precise regions of the embryo, tendons and ...ligaments share many properties and little is known about the molecular differences that differentiate them. Recent studies have revealed heterogeneity and plasticity within tendon and ligament cells, raising questions regarding the developmental mechanisms regulating tendon and ligament identity. Here, we discuss recent findings that contribute to our understanding of the mechanisms that establish and maintain tendon progenitors and their differentiated progeny in the head, trunk and limb. We also review the extent to which these findings are specific to certain anatomical regions and model organisms, and indicate which findings similarly apply to ligaments. Finally, we address current research regarding the cellular lineages that contribute to tendon and ligament repair, and to what extent their regulation is conserved within tendon and ligament development.
Arrhythmogenic cardiomyopathy (ACM) is a variably penetrant disease increasingly identified in young patients.
This study sought to describe the diverse phenotype, genotype, and outcomes in pediatric ...and adolescent patients.
Records from 1999 to 2016 were reviewed for individuals age <21 years with a consistent personal or family history. Patients were categorized by right ventricular (RV), left dominant (LD), or biventricular subtypes using 2010 Task Force Criteria or proposed features of LD disease, encompassing electrocardiographic, structural, histological, and arrhythmic characteristics. Genetic variants classified as pathogenic and/or likely pathogenic by 2015 American College of Medical Genetics and Genomics criteria in recognized disease-associated genes were included.
Manifest disease was evident in 32 patients (age 15.1 ± 3.8 years), of whom 22 were probands, including 16 RV, 7 LD, and 9 biventricular ACM. Nondiagnostic features were seen in 5 of 15 family members. RV disease was associated with cardiac arrest and ventricular tachycardia (p = 0.02) and prevalence of PKP2 variants (p < 0.01), whereas biventricular disease was associated with a younger age of onset (p = 0.02). LD ACM was associated with variants in DSP and LMNA, and biventricular ACM with more a diverse etiology in desmosomal genes. Cardiac arrest was observed in 5 probands (age 15.3 ± 1.9 years) and ventricular tachycardia in 10 (age 16.6 ± 2.7 years), 6 probands, and 4 family members. Features suggestive of myocardial inflammation were seen in 6 patients, with ventricular tachycardia and/or cardiac arrest in 3 patients. Cardiac transplantation was performed in 10 patients. There were no deaths. In RV and biventricular disease, electrocardiographic preceded imaging features, whereas the reverse was seen in LD disease.
ACM in the young has highly varied phenotypic expression incorporating life-threatening arrhythmia, heart failure, and myocardial inflammation. Increased awareness of early onset, aggressive disease has important implications for patient management and familial screening.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Congenital heart disease (CHD) is the most frequent birth defect, affecting 0.8% of live births. Many cases occur sporadically and impair reproductive fitness, suggesting a role for de novo ...mutations. Here we compare the incidence of de novo mutations in 362 severe CHD cases and 264 controls by analysing exome sequencing of parent-offspring trios. CHD cases show a significant excess of protein-altering de novo mutations in genes expressed in the developing heart, with an odds ratio of 7.5 for damaging (premature termination, frameshift, splice site) mutations. Similar odds ratios are seen across the main classes of severe CHD. We find a marked excess of de novo mutations in genes involved in the production, removal or reading of histone 3 lysine 4 (H3K4) methylation, or ubiquitination of H2BK120, which is required for H3K4 methylation. There are also two de novo mutations in SMAD2, which regulates H3K27 methylation in the embryonic left-right organizer. The combination of both activating (H3K4 methylation) and inactivating (H3K27 methylation) chromatin marks characterizes 'poised' promoters and enhancers, which regulate expression of key developmental genes. These findings implicate de novo point mutations in several hundreds of genes that collectively contribute to approximately 10% of severe CHD.
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DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The objective of this study was to identify trends and gaps in the field of implementation science in genomic medicine.
We conducted a literature review using the Centers for Disease Control and ...Prevention's Public Health Genomics Knowledge Base to examine the current literature in the field of implementation science in genomic medicine. We selected original research articles based on specific inclusion criteria and then abstracted information about study design, genomic medicine, and implementation outcomes. Data were aggregated, and trends and gaps in the literature were discussed.
Our final review encompassed 283 articles published in 2014, the majority of which described uptake (35.7%, n = 101) and preferences (36.4%, n = 103) regarding genomic technologies, particularly oncology (35%, n = 99). Key study design elements, such as racial/ethnic composition of study populations, were underreported in studies. Few studies incorporated implementation science theoretical frameworks, sustainability measures, or capacity building.
Although genomic discovery provides the potential for population health benefit, the current knowledge base around implementation to turn this promise into a reality is severely limited. Current gaps in the literature demonstrate a need to apply implementation science principles to genomic medicine in order to deliver on the promise of precision medicine.Genet Med advance online publication 12 January 2017.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Congenital heart disease (CHD) patients have an increased prevalence of extracardiac congenital anomalies (CAs) and risk of neurodevelopmental disabilities (NDDs). Exome sequencing of 1213 CHD ...parent-offspring trios identified an excess of protein-damaging de novo mutations, especially in genes highly expressed in the developing heart and brain. These mutations accounted for 20% of patients with CHD, NDD, and CA but only 2% of patients with isolated CHD. Mutations altered genes involved in morphogenesis, chromatin modification, and transcriptional regulation, including multiple mutations in RBFOX2, a regulator of mRNA splicing. Genes mutated in other cohorts examined for NDD were enriched in CHD cases, particularly those with coexisting NDD. These findings reveal shared genetic contributions to CHD, NDD, and CA and provide opportunities for improved prognostic assessment and early therapeutic intervention in CHD patients.
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BFBNIB, NMLJ, NUK, ODKLJ, PNG, SAZU, UL, UM, UPUK
The 22q11.2 deletion syndrome (22q11DS; velocardiofacial /DiGeorge syndrome; VCFS/DGS) is the most common microdeletion syndrome and the phenotypic presentation is highly variable. Approximately 65% ...of individuals with 22q11DS have a congenital heart defect (CHD), mostly of the conotruncal type, and/or an aortic arch defect. The etiology of this phenotypic variability is not currently known. We hypothesized that copy number variants (CNVs) outside the 22q11.2 deleted region might increase the risk of being born with a CHD in this sensitized population. Genotyping with Affymetrix SNP Array 6.0 was performed on two groups of 22q11DS subjects separated by time of ascertainment and processing. CNV analysis was completed on a total of 949 subjects (Cohort 1 n=562; Cohort 2 n=387), 603 with CHDs (Cohort 1 n=363; Cohort 2 n=240) and 346 with normal cardiac anatomy (Cohort 1 n=199; Cohort 2 n=147). Our analysis revealed that a duplication of SLC2A3 was the most frequent CNV identified in the first cohort. It was present in 18 subjects with CHDs and 1 subject without (p=3.12x10-3, two-tailed Fisher’s exact test). In the second cohort, the SLC2A3 duplication was also significantly enriched in subjects with CHDs (p=3.30x10-2, two-tailed Fisher’s exact test). The SLC2A3 duplication was the most frequent CNV detected and the only significant finding in our combined analysis (p=2.68x10-4, two-tailed Fisher’s exact test), indicating that the SLC2A3 duplication may serve as a genetic modifier of CHDs and/or aortic arch anomalies in individuals with 22q11DS.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Congenital heart disease (CHD) is the most common birth anomaly, affecting almost 1% of infants. Neurodevelopmental delay is the most common extracardiac feature in people with CHD. Many factors may ...contribute to neurodevelopmental risk, including genetic factors, CHD physiology, and the prenatal/postnatal environment. Damaging variants are most highly enriched among individuals with extracardiac anomalies or neurodevelopmental delay in addition to CHD, indicating that genetic factors have an impact beyond cardiac tissues in people with CHD. Potential sources of genetic risk include large deletions or duplications that affect multiple genes, such as 22q11 deletion syndrome, single genes that alter both heart and brain development, such as CHD7, and common variants that affect neurodevelopmental resiliency, such as APOE. Increased use of genome-sequencing technologies in studies of neurodevelopmental outcomes in people with CHD will improve our ability to detect relevant genes and variants. Ultimately, such knowledge can lead to improved and more timely intervention of learning support for affected children.
La cardiopathie congénitale (CC) est la malformation néonatale la plus fréquente. Elle touche près de 1 % des nouveau-nés. Le retard neurodéveloppemental constitue la caractéristique extracardiaque la plus répandue chez les sujets atteints de CC. De nombreux facteurs peuvent contribuer au risque neurodéveloppemental, notamment des facteurs génétiques, la physiologie de la CC et l’environnement pré ou postnatal. Les variantes dommageables constituent un fardeau plus lourd encore chez les sujets touchés par des anomalies extracardiaques ou un retard neurodéveloppemental en plus de la CC, ce qui indique que les facteurs génétiques ont un effet au-delà des tissus cardiaques en présence d’une CC. Les sources potentielles de risque génétique comprennent des délétions ou des duplications importantes qui affectent plusieurs gènes, comme le syndrome de délétion 22q11, des gènes uniques qui modifient le développement du cœur et du cerveau, comme CHD7, et des variantes communes qui nuisent à la résilience neurodéveloppementale, comme APOE. L’utilisation accrue des technologies de séquençage du génome dans le cadre des études sur les effets neurodéveloppementaux observés chez les sujets atteints de CC améliorera notre capacité à détecter les gènes et les variantes en cause. En fin de compte, les connaissances acquises peuvent permettre d’intervenir de meilleure façon et plus rapidement en matière d’aide à l’apprentissage auprès des enfants touchés.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP