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Browsing by Author "Landis, Benjamin J."
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Item A Multicenter Analysis of Abnormal Chromosomal Microarray Findings in Congenital Heart Disease(American Heart Association, 2023) Landis, Benjamin J.; Helvaty, Lindsey R.; Geddes, Gabrielle C.; Lin, Jiuann-Huey Ivy; Yatsenko, Svetlana A.; Lo, Cecilia W.; Border, William L.; Burns Wechsler, Stephanie; Murali, Chaya N.; Azamian, Mahshid S.; Lalani, Seema R.; Hinton, Robert B.; Garg, Vidu; McBride, Kim L.; Hodge, Jennelle C.; Ware, Stephanie M.; Pediatrics, School of MedicineBackground: Chromosomal microarray analysis (CMA) provides an opportunity to understand genetic causes of congenital heart disease (CHD). The methods for describing cardiac phenotypes in patients with CMA abnormalities have been inconsistent, which may complicate clinical interpretation of abnormal testing results and hinder a more complete understanding of genotype–phenotype relationships. Methods and Results: Patients with CHD and abnormal clinical CMA were accrued from 9 pediatric cardiac centers. Highly detailed cardiac phenotypes were systematically classified and analyzed for their association with CMA abnormality. Hierarchical classification of each patient into 1 CHD category facilitated broad analyses. Inclusive classification allowing multiple CHD types per patient provided sensitive descriptions. In 1363 registry patients, 28% had genomic disorders with well‐recognized CHD association, 67% had clinically reported copy number variants (CNVs) with rare or no prior CHD association, and 5% had regions of homozygosity without CNV. Hierarchical classification identified expected CHD categories in genomic disorders, as well as uncharacteristic CHDs. Inclusive phenotyping provided sensitive descriptions of patients with multiple CHD types, which occurred commonly. Among CNVs with rare or no prior CHD association, submicroscopic CNVs were enriched for more complex types of CHD compared with large CNVs. The submicroscopic CNVs that contained a curated CHD gene were enriched for left ventricular obstruction or septal defects, whereas CNVs containing a single gene were enriched for conotruncal defects. Neuronal‐related pathways were over‐represented in single‐gene CNVs, including top candidate causative genes NRXN3, ADCY2, and HCN1. Conclusions: Intensive cardiac phenotyping in multisite registry data identifies genotype–phenotype associations in CHD patients with abnormal CMA.Item Activation of the Hedgehog signaling pathway leads to fibrosis in aortic valves(BMC, 2023-03-02) Gu, Dongsheng; Soepriatna, Arvin H.; Zhang, Wenjun; Li, Jun; Zhao, Jenny; Zhang, Xiaoli; Shu, Xianhong; Wang, Yongshi; Landis, Benjamin J.; Goergen, Craig J.; Xie, Jingwu; Pediatrics, School of MedicineBackground: Fibrosis is a pathological wound healing process characterized by excessive extracellular matrix deposition, which interferes with normal organ function and contributes to ~ 45% of human mortality. Fibrosis develops in response to chronic injury in nearly all organs, but the a cascade of events leading to fibrosis remains unclear. While hedgehog (Hh) signaling activation has been associated with fibrosis in the lung, kidney, and skin, it is unknown whether hedgehog signaling activation is the cause or the consequence of fibrosis. We hypothesize that activation of hedgehog signaling is sufficient to drive fibrosis in mouse models. Results: In this study, we provide direct evidence to show that activation of Hh signaling via expression of activated smoothened, SmoM2, is sufficient to induce fibrosis in the vasculature and aortic valves. We showed that activated SmoM2 -induced fibrosis is associated with abnormal function of aortic valves and heart. The relevance of this mouse model to human health is reflected in our findings that elevated GLI expression is detected in 6 out of 11 aortic valves from patients with fibrotic aortic valves. Conclusions: Our data show that activating hedgehog signaling is sufficient to drive fibrosis in mice, and this mouse model is relevant to human aortic valve stenosis.Item Adolescents with Congenital Heart Disease: a Patient and Parental Perspective of Genetic Information and Genetic Risk(Cambridge University Press, 2020-02) Crawford, Christopher A.; Vujakovich, Courtney E.; Elmore, Lindsey; Fleming, Emily; Landis, Benjamin J.; Spoonamore, Katie G.; Ware, Stephanie M.; Pediatrics, School of MedicineCongenital heart defects (CHDs) occur in 8 of 1000 live-born children, making them common birth defects in the adolescent population. CHDs may have single gene, chromosomal, or multifactorial causes. Despite evidence that patients with CHD want information on heritability and genetics, no studies have investigated the interest or knowledge base in the adolescent population. This information is necessary as patients in adolescence take greater ownership of their health care and discuss reproductive risks with their physicians. The objectives of this survey-based study were to determine adolescents' recall of their own heart condition, to assess patient and parent perception of the genetic contribution to the adolescent's CHD, and to obtain information about the preferred method(s) for education. The results show that adolescent patients had good recall of their type of CHD. Less than half of adolescents and parents believed their CHD had a genetic basis or was heritable; however, adolescents with a positive family history of CHD were more likely to believe that their condition was genetic (p = 0.0005). The majority of patients were interested in receiving additional genetics education and preferred education in-person and in consultation with both parents and a physician. The adolescents who felt most competent to have discussions with their doctors regarding potential causes of their heart defect previously had a school science course which covered topics in genetics. These results provide insight into adolescents' perceptions and understanding about their CHD and genetic risk and may inform the creation and provision of additional genetic education.Item Bicuspid Aortic Valve: a Review with Recommendations for Genetic Counseling(Springer, 2016-12) Freeze, Samantha L.; Landis, Benjamin J.; Ware, Stephanie M.; Helm, Benjamin M.; Department of Pediatrics, IU School of MedicineBicuspid aortic valve (BAV) is the most common congenital heart defect and falls in the spectrum of left-sided heart defects, also known as left ventricular outflow tract obstructive (LVOTO) defects. BAV is often identified in otherwise healthy, asymptomatic individuals, but it is associated with serious long term health risks including progressive aortic valve disease (stenosis or regurgitation) and thoracic aortic aneurysm and dissection. BAV and other LVOTO defects have high heritability. Although recommendations for cardiac screening of BAV in at-risk relatives exist, there are no standard guidelines for providing genetic counseling to patients and families with BAV. This review describes current knowledge of BAV and associated aortopathy and provides guidance to genetic counselors involved in the care of patients and families with these malformations. The heritability of BAV and recommendations for screening are highlighted. While this review focuses specifically on BAV, the principles are applicable to counseling needs for other LVOTO defects.Item Characterization of the Rate of Aortic Dilation in Young Patients with Thoracic Aortic Aneurysm(Springer, 2021) Wheeler, Adam P.; Yang, Ziyi; Cordes, Timothy M.; Markham, Larry W.; Landis, Benjamin J.; Pediatrics, School of MedicineLongitudinal changes in aortic diameters of young patients with thoracic aortic aneurysm (TAA) have not been completely described, particularly over long periods of follow-up. This retrospective study sought to characterize the rates of proximal aortic dilation in young patients, identify risk factors for TAA progression, and evaluate the predictive utility of early echocardiographic follow-up. Inclusion criteria were: (1) TAA or TAA-predisposing genetic diagnosis, (2) age < 25 years at first echocardiogram, and (3) minimum of 5 years of echocardiographic follow-up. Proximal aortic diameters were measured by echocardiography and Z-scores calculated to index for body surface area. TAA severity was classified as no TAA (Z-score < 2), mild (Z-score 2 to 4), or at least moderate (Z-score > 4). Among 141 included patients, mean age at first echocardiogram was 7.3 ± 3.5 years. Mean follow-up duration was 9.8 ± 3.5 years. Fifty five patients had a genetic syndrome, and 38 of the non-syndromic patients had bicuspid aortic valve (BAV). The rate of aortic dilation was significantly higher at the ascending aorta than other aortic segments. BAV and age > 10 years at first echocardiogram were associated with increased rate of ascending aorta dilation. At the ascending aorta, over 25% of patients had categorical increase in TAA severity between first and last echocardiograms, and such patients demonstrated higher rate of dilation within their first 2 years of follow-up. These longitudinal findings highlight progressive ascending aorta dilation in young patients, which may worsen around adolescence. This may help determine timing of follow-up and target ages for clinical trials.Item CHD associated with syndromic diagnoses: peri-operative risk factors and early outcomes(Cambridge University Press, 2016-01) Landis, Benjamin J.; Cooper, David S.; Hinton, Robert B.; Department of Pediatrics, IU School of MedicineCHD is frequently associated with a genetic syndrome. These syndromes often present specific cardiovascular and non-cardiovascular co-morbidities that confer significant peri-operative risks affecting multiple organ systems. Although surgical outcomes have improved over time, these co-morbidities continue to contribute substantially to poor peri-operative mortality and morbidity outcomes. Peri-operative morbidity may have long-standing ramifications on neurodevelopment and overall health. Recognising the cardiovascular and non-cardiovascular risks associated with specific syndromic diagnoses will facilitate expectant management, early detection of clinical problems, and improved outcomes--for example, the development of syndrome-based protocols for peri-operative evaluation and prophylactic actions may improve outcomes for the more frequently encountered syndromes such as 22q11 deletion syndrome.Item Chromosome 4q28.3q32.3 duplication in a patient with lymphatic malformations, craniosynostosis, and dysmorphic features(Wolters Kluwer, 2021) Traub, Eric S.; Sheppard, Sarah E.; Dori, Yoav; Burns, Katelyn D.; Zackai, Elaine H.; Ware, Stephanie M.; Landis, Benjamin J.; Li, Dong; Weaver, David D.; Medical and Molecular Genetics, School of MedicineThe proband, now a 4-year-old female of mixed Caucasian and Japanese ancestry, was born at 29 weeks gestation via spontaneous vaginal delivery following a pregnancy complicated by fetal ascites, echogenic bowel, polyhydramnios, and incompetent cervix. The mother had no other pregnancy complications and had no recognized teratogen exposures throughout the pregnancy. Her length was 37 cm (37th centile), weight was 1.478 kg (80th centile), and occipitofrontal circumference (OFC) was 27 cm (20th centile). The family history was significant for maternal family members with pregnancy losses of unknown etiology: one each for the mother and maternal grandmother. The great maternal grandmother reported at least 4 or 5 pregnancy losses. Consanguinity was denied. The proband remained in the neonatal intensive care unit for the next 8 months for management of severe respiratory issues, ascites and feeding difficulties. During that time, she underwent placement of a tracheostomy, a Denver (peritoneovenous) shunt for ascitic-fluid drainage, an intravenous port and a gastrostomy tube for feeds (Fig. 1). Additional pertinent findings then include retinopathy of prematurity, subglottal stenosis grade IV, hypothyroidism, 11 sets of ribs, mild bilateral hydronephrosis, accessory spleen and persistent ascites (Fig. 2). At 20 months dysmorphologic evaluation was significant for macrocephaly, open anterior and posterior fontanelles, bicoronal craniosynostosis on CT scan, right posterior plagiocephaly, brachycephaly, cupped and prominent ears with hypoplastic antihelices, broad forehead, a short and upturned nose, telecanthus, ocular hypertelorism, depressed nasal bridge (Figure 3A–B), moderate ascites, bilateral overriding of the second and fourth toes over the third toe, short stature and hypotonia. At this latter time, she exhibited significant developmental delays; she was unable to sit unassisted or feed herself. However, she was able to crawl, pull to a stand and sit independently. The proband could feed herself but still required a G-tube for much of her nutrition. She was nonverbal but able to use 12 signs. She continued to require a tracheostomy but only for night-time mechanical ventilation. At 33 months when last evaluated, her height was 79.2 cm (<1st centile), weight was 11.6 kg (7th centile) and OFC was 56 cm (>97th centile). The patient’s severe ascites persisted throughout the first 2 years of her life. At age 22 months, she underwent lymphatic imaging at the Children’s Hospital of Philadelphia that revealed multiple dilated perihepatic lymphatic vessels and leakage of contrast material into the peritoneum (Fig. 4A–D). Subsequently, she underwent successful embolization of these lymphatic vessels with resolution of her ascites.Item Clinically relevant variants identified in thoracic aortic aneurysm patients by research exome sequencing(Wiley Blackwell (John Wiley & Sons), 2016-05) Schubert, Jeffrey A.; Landis, Benjamin J.; Shikany, Amy R.; Hinton, Robert B.; Ware, Stephanie M.; Department of Pediatrics, IU School of MedicineThoracic aortic aneurysm (TAA) is a genetically heterogeneous disease involving subclinical and progressive dilation of the thoracic aorta, which can lead to life-threatening complications such as dissection or rupture. Genetic testing is important for risk stratification and identification of at risk family members, and clinically available genetic testing panels have been expanding rapidly. However, when past testing results are normal, there is little evidence to guide decision-making about the indications and timing to pursue additional clinical genetic testing. Results from research based genetic testing can help inform this process. Here we present 10 TAA patients who have a family history of disease and who enrolled in research-based exome testing. Nine of these ten patients had previous clinical genetic testing that did not identify the cause of disease. We sought to determine the number of rare variants in 23 known TAA associated genes identified by research-based exome testing. In total, we found 10 rare variants in six patients. Likely pathogenic variants included a TGFB2 variant in one patient and a SMAD3 variant in another. These variants have been reported previously in individuals with similar phenotypes. Variants of uncertain significance of particular interest included novel variants in MYLK and MFAP5, which were identified in a third patient. In total, clinically reportable rare variants were found in 6/10 (60%) patients, with at least 2/10 (20%) patients having likely pathogenic variants identified. These data indicate that consideration of re-testing is important in TAA patients with previous negative or inconclusive results.Item A Comprehensive Clinical Genetics Approach to Critical Congenital Heart Disease in Infancy(Elsevier, 2020-12) Shikany, Amy R.; Landis, Benjamin J.; Parrott, Ashley; Miller, Erin M.; Coyan, Alyxis; Walters, Lauren; Hinton, Robert B.; Goldenberg, Paula; Ware, Stephanie M.; Medical and Molecular Genetics, School of MedicineObjective: To investigate the frequency of genetic diagnoses among infants with critical congenital heart disease (CHD) using a comprehensive cardiovascular genetics approach and to identify genotype-phenotype correlations. Study design: A retrospective chart review of patients evaluated by cardiovascular genetics in a pediatric cardiac intensive care unit from 2010 to 2015 was performed. Infants with CHD who were <1 month of age were included. CHD was classified using structured phenotype definitions. Cardiac and noncardiac phenotypes were tested for associations with abnormal genetic testing using χ1 and Fisher exact tests. Results: Genetic evaluation was completed in 293 infants with CHD, of whom 213 had isolated congenital heart disease (iCHD) and 80 had multiple congenital anomalies. Overall, the yield of abnormal genetic testing was 26%. The multiple congenital anomalies cohort had a greater yield of genetic testing (39%) than the iCHD cohort (20%) (OR 2.7). Using a non-hierarchical CHD classification and excluding 22q11.2 deletion and common aneuploidies, right ventricular obstructive defects were associated with abnormal genetic testing (P = .0005). Extracardiac features associated with abnormal genetic testing included ear, nose, and throat (P = .003) and brain (P = .0001) abnormalities. A diagnosis of small for gestational age or intrauterine growth retardation also was associated with abnormal genetic testing (P = .0061), as was presence of dysmorphic features (P = .0033, OR 3.5). Infants without dysmorphia with iCHD or multiple congenital anomalies had similar frequencies of abnormal genetic testing. Conclusions: The present study provides evidence to support a comprehensive cardiovascular genetics approach in evaluating infants with critical CHD while also identifying important genotype-phenotype considerations.Item The Current Landscape of Genetic Testing in Cardiovascular Malformations: Opportunities and Challenges(Frontiers, 2016-07-25) Landis, Benjamin J.; Ware, Stephanie M.; Department of Pediatrics, IU School of MedicineHuman cardiovascular malformations (CVMs) frequently have a genetic contribution. Through the application of novel technologies, such as next-generation sequencing, DNA sequence variants associated with CVMs are being identified at a rapid pace. While clinicians are now able to offer testing with NGS gene panels or whole exome sequencing to any patient with a CVM, the interpretation of genetic variation remains problematic. Variable phenotypic expression, reduced penetrance, inconsistent phenotyping methods, and the lack of high-throughput functional testing of variants contribute to these challenges. This article elaborates critical issues that impact the decision to broadly implement clinical molecular genetic testing in CVMs. Major benefits of testing include establishing a genetic diagnosis, facilitating cost-effective screening of family members who may have subclinical disease, predicting recurrence risk in offsprings, enabling early diagnosis and anticipatory management of CV and non-CV disease phenotypes, predicting long-term outcomes, and facilitating the development of novel therapies aimed at disease improvement or prevention. Limitations include financial cost, psychosocial cost, and ambiguity of interpretation of results. Multiplex families and patients with syndromic features are two groups where disease causation could potentially be firmly established. However, these account for the minority of the overall CVM population, and there is increasing recognition that genotypes previously associated with syndromes also exist in patients who lack non-CV findings. In all circumstances, ongoing dialog between cardiologists and clinical geneticists will be needed to accurately interpret genetic testing and improve these patients' health. This may be most effectively implemented by the creation and support of CV genetics services at centers committed to pursuing testing for patients.
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