Current approach to genetic testing and genetic evaluation referrals for adults with congenital heart disease.

Background: Congenital heart disease (CHD) is the most common congenital anomaly. Up to 33% have an identifiable genetic etiology. Improved medical and surgical management of CHD has translated into longer life expectancy and a rapidly growing population of adults living with CHD. The adult CHD (ACHD) population did not have access during childhood to the genetic technologies available today and therefore have not had a robust genetic evaluation that is currently recommended for infants with CHD. Given this potential benefit; the aims of this study were to determine how ACHD cardiologists offer genetics services to patients and identify the indications that influence decision-making for genetics care. Methods: We performed a descriptive cross-sectional study of ACHD cardiologists. A study-developed questionnaire was distributed via emailed REDCap link. The recruitment email was sent to 104 potential respondents. The survey was open from 06/2022 to 01/2023. Results: Thirty-five cardiologists participated in the study (response rate of 34%). Most cardiologists identified as white (77%) and male (66%). Cardiologists were more likely to refer patients to genetics (91%) than to order testing themselves (57%). Of the testing ordered, chromosomal testing (55%) was ordered more than gene sequencing (14%). Most cardiologists would refer a patient with a conotruncal lesion (interrupted aortic arch) over other indications for a genetics evaluation. There were more reported barriers to ordering genetic testing (66%) compared to referring to genetics for a genetics evaluation (23%). Cardiologists were more confident recognizing features suggestive of a genetic syndrome than ordering the correct test (p = 0.001). Regarding associations between clinical factors and current practices, more years in practice trended towards less referrals and testing. Evaluating a greater number of patients (p = 0.11) and greater confidence recognizing syndromic features (p = 0.12) and ordering the correct test (p = 0.09) were all associated with ordering more testing. Conclusion: Testing for microdeletion syndromes is being offered and completed in the ACHD population, however testing for single-gene disorders associated with CHD is being under-utilized. Developing guidelines for genetic testing in adults with CHD could increase access to genetic services, impact medical management, reduce uncertainty regarding prognosis, and inform recurrence risk estimates.

Phenotypes and genotypes in a cohort of children with single-ventricle CHD.

OBJECTIVE: CHD is known to be associated with increased risk for neurodevelopmental disorders. The combination of CHD with neurodevelopmental disorders and/or extra-cardiac anomalies increases the chance for an underlying genetic diagnosis. Over the last 15 years, there has been a dramatic increase in the use of broad-scale genetic testing. We sought to determine if neurodevelopmental disorders in children with single-ventricle CHD born prior to the genetic testing revolution are associated with genetic diagnosis. METHODS: We identified 74 5-12-year-old patients with single-ventricle CHD post-Fontan procedure. We retrospectively evaluated genetic testing performed and neurodevelopmental status of these patients. RESULTS: In this cohort, there was an overall higher rate of neurodevelopmental disorders (80%) compared to the literature (50%). More of the younger (5-7-year-old) patients were seen by genetic counsellors compared to the older (8-12-year-old) cohort (46% versus 19% p value = 0.01). In the younger cohort, the average age of initial consultation was 7.7 days compared to 251 days in the older cohort. The overall rate of achieving a molecular diagnosis was 12% and 8% in the younger and older cohorts, respectively; however, the vast majority of did not have broad genetic testing. CONCLUSION: The minority of patients in our cohort achieved a genetic diagnosis. Given a large increase in the number of genes associated with monogenic CHD and neurodevelopmental disorders in the last decade, comprehensive testing and consultation with clinical genetics should be considered in this age range, since current testing standards did not exist during their infancy.

Using deep learning and electronic health records to detect Noonan syndrome in pediatric patients.

PURPOSE: The variable expressivity and multisystem features of Noonan syndrome (NS) make it difficult for patients to obtain a timely diagnosis. Genetic testing can confirm a diagnosis, but underdiagnosis is prevalent owing to a lack of recognition and referral for testing. Our study investigated the utility of using electronic health records (EHRs) to identify patients at high risk of NS. METHODS: Using diagnosis texts extracted from Cincinnati Children's Hospital's EHR database, we constructed deep learning models from 162 NS cases and 16,200 putative controls. Performance was evaluated on 2 independent test sets, one containing patients with NS who were previously diagnosed and the other containing patients with undiagnosed NS. RESULTS: Our novel method performed significantly better than the previous method, with the convolutional neural network model achieving the highest area under the precision-recall curve in both test sets (diagnosed: 0.43, undiagnosed: 0.16). CONCLUSION: The results suggested the validity of using text-based deep learning methods to analyze EHR and showed the value of this approach as a potential tool to identify patients with features of rare diseases. Given the paucity of medical geneticists, this has the potential to reduce disease underdiagnosis by prioritizing patients who will benefit most from a genetics referral.

The MAP3K7 gene: Further delineation of clinical characteristics and genotype/phenotype correlations.

Mitogen-activated protein 3 kinase 7 (MAP3K7) encodes the ubiquitously expressed transforming growth factor ß-activated kinase 1, which plays a crucial role in many cellular processes. Mutationsin the MAP3K7 gene have been linked to two distinct disorders: frontometaphyseal dysplasia type 2 (FMD2) and cardiospondylocarpofacial syndrome (CSCF). The fact that different mutations can induce two distinct phenotypes suggests a phenotype/genotype correlation, but no side-by-side comparison has been done thus far to confirm this. Here, we significantly expand the cohort and the description of clinical phenotypes for patients with CSCF and FMD2 who carry mutations in MAP3K7. Our findings support that in contrast to FMD2-causing mutations, CSCF-causing mutations in MAP3K7 have a loss-of-function effect. Additionally, patients with pathogenic mutations in MAP3K7 are at risk for (severe) cardiac disease, have symptoms associated with connective tissue disease, and we show overlap in clinical phenotypes of CSCF with Noonan syndrome (NS). Together, we confirm a molecular fingerprint of FMD2- versus CSCF-causing MAP3K7 mutations and conclude that mutations in MAP3K7 should be considered in the differential diagnosis of patients with syndromic congenital cardiac defects and/or cardiomyopathy, syndromic connective tissue disorders, and in the differential diagnosis of NS.

Prevalence of Genetic Diagnoses in a Cohort With Valvar Pulmonary Stenosis.

BACKGROUND: Valvar pulmonary stenosis (vPS) accounts for 8% to 12% of congenital heart disease cases. Multiple genetic syndromes are associated with vPS, most commonly Noonan syndrome, but the cause is unknown in most cases. We analyzed genomic data from a large cohort with vPS to determine the prevalence of genetic diagnosis. METHODS: The Pediatric Cardiac Genomics Consortium database was queried to identify probands with vPS without complex congenital heart disease or aneuploidy and with existing whole exome or genome sequencing. A custom analysis workflow was used to identify likely pathogenic or pathogenic variants in disease-associated genes. Demographic and phenotypic characteristics were compared between groups with and without molecular diagnoses. RESULTS: Data from 119 probands (105 trios) were included. A molecular diagnosis was identified in 22 (18%); 17 (14%) had Noonan syndrome or a related disorder. Extracardiac and neurodevelopmental comorbidities were seen in 67/119 (56%) of probands. Molecular diagnosis was more common in those with extracardiac and neurodevelopmental phenotypes than those without (18/67 versus 4/52, P=0.0086). CONCLUSIONS: Clinicians should have high suspicion for a genetic diagnosis in individuals with vPS, particularly if additional phenotypes are present. Our results suggest that clinicians should consider offering sequencing of at least the known congenital heart disease and RASopathy genes to all individuals with vPS, regardless of whether that individual has extracardiac or neurodevelopmental phenotypes present.

Retrospective comparison of parent-reported genetics knowledge, empowerment, and familial uptake of cardiac screening between parents who received genetic counseling by a certified genetic counselor and those who did not: A single US academic medical center study.

Bicuspid aortic valve (BAV) is the most common congenital heart defect, which can cause severe cardiac complications. BAVs cluster in families and demonstrate high heritability. Cardiac screening for first-degree relatives of individuals with a BAV is recommended. This retrospective two-group study evaluated the impact of cardiovascular genetic counseling provided by a board-certified genetic counselor on parent-reported outcomes by comparing parental responses of those who received genetic counseling by a genetic counselor (GC group) for family history of BAV to those who did not (non-GC group). A retrospective chart review from May 2016 to June 2019 identified 133 pediatric patients with an isolated BAV. Parents of eligible probands were invited to complete an online survey assessing genetics knowledge, empowerment (Genomics Outcome Scale), and familial uptake of cardiac screening. Surveys were completed by 38/97 (39%) parents in the non-GC group and 20/36 (56%) parents in the GC group. The median genetics knowledge score was not significantly different between the two groups (GC group: 8, range 3-11 out of a maximum possible of 12; non-GC group: 7, range 2-11; p = .08). The mean empowerment score was not significantly different between the two groups (GC group: mean 24.6, SD 2.2; non-GC group: mean 23.2, SD 3.5; p = .06). The uptake of cardiac screening was significantly higher in the GC group with 39/59 (66%) total first-degree relatives reported as having been screened compared with 36/91 (40%) in the non-GC group (p = .002). Parent-reported outcomes in our study suggest that receiving genetic counseling by a board-certified genetic counselor significantly increased familial uptake of cardiac screening for first-degree relatives of pediatric patients with a BAV. Studies with larger sample sizes are needed to confirm the findings of this study; however, a referral to a genetic counselor should be considered for patients with a BAV.

Genetic counseling for congenital heart disease - Practice resource of the National Society of Genetic Counselors.

Congenital heart disease (CHD) is an indication which spans multiple specialties across various genetic counseling practices. This practice resource aims to provide guidance on key considerations when approaching counseling for this particular indication while recognizing the rapidly changing landscape of knowledge within this domain. This resource was developed with consensus from a diverse group of certified genetic counselors utilizing literature relevant for CHD genetic counseling practice and is aimed at supporting genetic counselors who encounter this indication in their practice both pre- and postnatally.

Uptake of Screening and Recurrence of Bicuspid Aortic Valve and Thoracic Aortic Aneurysm Among At-Risk Siblings of Pediatric Probands.

OBJECTIVE: To determine uptake of cardiac screening and recurrence of bicuspid aortic valve (BAV) and thoracic aortic aneurysm (TAA) in a population of at-risk siblings of pediatric probands. STUDY DESIGN: A retrospective chart review of pediatric patients with known BAV and/or TAA was performed. Echocardiogram data from identified siblings were collected to determine screening uptake and recurrence of BAV and TAA. Statistical analyses were performed using Wilcoxon signed-rank test and chi-square. RESULTS: The cohort included 251 probands and 388 at-risk siblings. Among the siblings, 150 had at least 1 echocardiogram, giving an overall screening uptake of 38.7%. The only factor found to be associated with increased uptake was documented recommendation for screening of first-degree relatives in the proband's initial cardiology note (P = .03). A total of 11 screened siblings (7.3%) had BAV and 19 had TAA (12.7%), with an overall combined recurrence of 15.3%. Siblings of probands who had both BAV and TAA had increased recurrence of TAA compared with siblings of probands with isolated BAV (16.1% vs 3.9%, respectively). CONCLUSIONS: Given low uptake in at-risk siblings, the opportunity exists to assess barriers for families in pursuing the recommended screening. Furthermore, the relatively high recurrence of BAV and TAA in at-risk siblings highlights the potential for improved health outcomes through increased screening and early detection. Developing standardized guidelines and promoting early cardiac screening in at-risk siblings while counseling families about hereditary risk for BAV and TAA may help improve uptake and optimize clinical management in at-risk pediatric patients.

Rotational Position of the Aortic Root is Associated with Increased Aortic Dimensions in Marfan and Loeys-Dietz Syndrome.

Progressive aortic dilation is common in Marfan syndrome (MFS) and Loeys-Dietz syndrome (LDS). Risk factors for progression are poorly understood. Normal variation in the aortic root (AoR) rotational position relative to the left ventricular base may impact this risk. We aimed to assess the relationship between the rotational position of the AoR and aortic dimensions in this population. Patients with a genetic diagnosis of MFS or LDS were included. AoR and ascending aorta (AAo) dimensions were measured from the first and most recent transthoracic echocardiogram. The AoR rotational angle was measured in the parasternal short-axis plane in diastole. Linear regression was used to study the correlation between AoR rotation angle and aortic dimensions. 53 MFS and 14 LDS patients were included (age 11.5 ± 5.8 years at first TTE and 21.2 ± 7.2 years at most recent, 68% male). The mean indexed AoR and AAo values were 2.26 ± 0.58 cm/m2 and 1.64 ± 0.35 cm/m2 at the first TTE and 1.98 ± 0.39 cm/m2 and 1.45 ± 0.25 cm/m2 at the most recent TTE, respectively. The mean AoR rotational angle was 8 ± 14°. AoR rotational angle was central (- 9 to + 14°) in 42, clockwise (≥ + 15°) in 19, and counterclockwise (≤ -10°) in 6. The six outliers with counterclockwise position were excluded. There was a positive association between the AoR rotation angle and most recent TTE indexed AoR (r2 = 0.08, p = 0.02) and AAo sizes (r2 = 0.08, p = 0.02). There was no association between AoR rotational angle and rate of change in indexed AoR size (p = 0.8). There was a positive association between AoR rotation angle and rate of change in indexed AAo size (r2 = 0.10, p = 0.01). There is an association between clockwise rotational position of the AoR and increased AoR and AAo dimensions in children and young adults with MFS and LDS patients. The rotational position of the AoR may guide follow-up in these patient populations. However, this potential risk factor for dilation warrants further investigation.

A Comprehensive Clinical Genetics Approach to Critical Congenital Heart Disease in Infancy.

OBJECTIVE: 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.

Comparison of Evolution of Aortic Root Dilation and Ghent Criteria in Preadolescents and Adolescents with and without Marfan Syndrome.

OBJECTIVE: To determine whether the Ghent Criteria (2010) can be reliably used in evaluating preadolescents and adolescents for Marfan syndrome by comparing aortic growth, systemic scores, and anthropometric features in individuals with and without Marfan syndrome. STUDY DESIGN: A retrospective chart review was completed for patients less than 15 years of age referred for Marfan syndrome. Comparisons were made between the first and last visit. Paired t tests were used to compare Ghent systemic scores. Wilcoxon rank-sum test were used to compare age, aortic root z scores, height z scores, and body mass index z scores. Recursive partitioning was used to identify combinations of factors to distinguish Marfan syndrome. RESULTS: In total, 53 individuals met inclusion criteria (29 Marfan syndrome and 24 non-Marfan syndrome). Ghent systemic score increased in the Marfan syndrome group and declined in the non-Marfan syndrome. The non-Marfan syndrome group did not develop progressive aortic root dilation with age. Individuals with Marfan syndrome had higher median height z scores than non-Marfan syndrome, with no difference in median body mass index z score between groups. A combination of aortic root z score above 0.95 and Ghent systemic score above 3 was highly indicative of a Marfan syndrome diagnosis in children less than 15 years of age. CONCLUSION: The Ghent criteria (2010) can be used to reliably exclude a diagnosis of Marfan syndrome in individuals less than 15 years of age. Genetic testing should be used as an aide in confirming or excluding the diagnosis of Marfan syndrome in individuals with an aortic root z score above 0.95 in combination with a Ghent systemic score above 3 at initial visit.

Investigation of de novo variation in pediatric cardiomyopathy.

Pediatric cardiomyopathies can be caused by variants in genes encoding the sarcomere and cytoskeleton in cardiomyocytes. Variants are typically inherited in an autosomal dominant manner with variable expressivity. De novo variants have been reported, however their overall frequency is largely unknown. We sought to determine the rate of de novo, pathogenic and likely pathogenic (P/LP) variants in children with a diagnosis of hypertrophic, dilated, or restrictive cardiomyopathy (HCM, DCM, or RCM), and to compare disease outcomes between individuals with and without a de novo variant. A retrospective record review identified 126 individuals with HCM (55%), DCM (37%), or RCM (8%) ≤18 years of age who had genetic testing. Overall, 50 (40%) had positive genetic testing and 18% of P/LP variants occurred de novo. The rate of de novo variation in those with RCM (80%) was higher than in those with HCM (9%) or DCM (20%). There was evidence of germline mosaicism in one family with RCM. Individuals with de novo variants were more likely than those without to have a history of arrhythmia (p = .049), sudden cardiac arrest (p = .024), hospitalization (p = .041), and cardiac transplantation (p = .030). The likelihood of de novo variation and impact on family risk and screening should be integrated into genetic counseling.

Medically actionable comorbidities in adults with Costello syndrome.

Costello syndrome (CS) is an autosomal-dominant condition caused by activating missense mutations in HRAS. There is little literature describing health concerns specific to adults with CS. Parents of individuals with CS need to know what to anticipate as their children age. We surveyed a group of 20 adults and older adolescents with CS regarding their medical concerns and lifestyle characteristics. We identified several previously undescribed actionable medical concerns in adults with CS. First, the high prevalence of anxiety in this cohort indicates that screening for anxiety is warranted since this is a treatable condition that can have a significant impact on quality of life. Second, adults with CS should be monitored for progressive contractures or other problems that could decrease mobility. This is especially important in a population that seems to have increased risk for osteopenia. Finally, the lack of cancer diagnoses in adulthood is of interest, although the cohort is too small to draw definitive conclusions about cancer risk in adults with CS. Ongoing follow-up of the current cohort of adults with CS is necessary to delineate progressive medical and physical problems, which is essential for providing targeted management recommendations and anticipatory guidance to families.

Left ventricular outflow tract obstruction: Uptake of familial cardiac screening and parental knowledge from a single tertiary care center.

Left ventricular outflow tract obstruction (LVOTO) malformations exhibit higher heritability than other cardiac lesions and cardiac screening is encouraged for first-degree relatives. This study sought to determine the uptake of familial cardiac screening in families with an infant with an LVOTO and assess parental knowledge regarding genetics and heritability of LVOTO. A chart review of the period 2010-2015 identified 69 families who received genetic counseling regarding a diagnosis of LVOTO in an infant. Surveys assessing familial cardiac screening and parental knowledge were completed by a parent in 24 families (completion rate of 35%). Forty percent (36/89) of all at-risk first-degree family members completed cardiac screening. The presence of additional congenital malformations in the affected infant was the only significant factor reducing the uptake of familial cardiac screening (p = 0.003). The reported uptake of screening for subsequent at-risk pregnancies was 11/12 (92%) compared to 25/77 (32%) of living at-risk relatives. Survey respondents answered seven knowledge questions with an average score of 5.2 and all correctly identified that LVOTO can run in families. Uptake of familial cardiac screening is occurring in less than half of at-risk individuals, despite parents demonstrating basic knowledge and receiving genetic counseling. Follow-up counseling in the outpatient setting to review familial screening recommendations should be considered to increase uptake and optimize outcomes.

Prevalence of Noonan spectrum disorders in a pediatric population with valvar pulmonary stenosis.

OBJECTIVE: To evaluate the prevalence of Noonan spectrum disorders (NSD) in a pediatric population with valvar pulmonary stenosis (vPS) and identify the clinical characteristics that differentiate those with NSD from those without NSD. DESIGN: A retrospective chart review of 204 patients diagnosed with vPS between 9/1/2012 and 12/1/2016 at a pediatric medical center was performed. The quantitative features of vPS, genetic diagnosis information, and phenotypic characteristics of Noonan syndrome were collected. Chi-square test, Fisher's exact test, t test, Wilcoxon rank-sum test, and ANOVA were used for comparisons among the groups. Logistic regression was used to test for the association between the clinical characteristics and the presence of NSD. RESULTS: Syndromic diagnoses were made in 10% of the children with vPS, with NSD accounting for 6%. Hypertrophic cardiomyopathy (P < .0001), short stature (P < .0001), developmental delay (P < .0001), ophthalmological abnormalities (P < .0001), pectus carinatum/excavatum (P = .01), neurological abnormalities (P = .022), and aortic stenosis (P = .031) were present more often in individuals with NSD compared to nonsyndromic vPS. A logistic regression analysis showed a 4.8-fold increase in odds for NSD for each additional characteristic (P < .0001). CONCLUSIONS: At least 6% of the children with vPS have an underlying NSD. Individuals with vPS and NSD were significantly more likely to have additional features known to be associated with NSD than those with vPS without NSD. We conclude that vPS in the presence of one or more significant characteristics should prompt referral for genetic evaluation as a guide to ascertain patients at risk for NSD while optimizing the use of clinical genetics evaluation and potential genetic testing.

Hypertrophic Cardiomyopathy Genotype Prediction Models in a Pediatric Population.

The Toronto Hypertrophic Cardiomyopathy (HCM) Genotype Score and Mayo HCM Genotype Predictor are risk assessment models developed to estimate a patient's likelihood of testing positive for a pathogenic variant causative of HCM. These models were developed from adult populations with HCM based on factors that have been associated with a positive genotype and have not been validated in external populations. The purpose of this study was to evaluate the overall predictive abilities of these models in a clinical pediatric HCM setting. A retrospective medical record review of 77 pediatric patients with gene panel testing for HCM between September 2005 and June 2015 was performed. Clinical and echocardiographic variables used in the developed models were collected and used to calculate scores for each patient. To evaluate model performance, the ability to discriminate between a carrier and non-carrier was assessed by area under the ROC curve (AUC) and overall calibration was evaluated by the Hosmer-Lemeshow goodness-of-fit statistic. Discrimination assessed by AUC was 0.72 (P < 0.001) for the Toronto model and 0.67 (P = 0.004) for the Mayo model. The Toronto model and the Mayo model showed P values of 0.36 and 0.82, respectively, for model calibration. Our findings suggest that these models are useful in predicting a positive genetic test result in a pediatric HCM setting. They may be used to aid healthcare providers in communicating risk and enhance patient decision-making regarding pursuit of genetic testing.

Genetic Testing in Pediatric Left Ventricular Noncompaction.

BACKGROUND: Left ventricular noncompaction (LVNC) can occur in isolation or can co-occur with a cardiomyopathy phenotype or cardiovascular malformation. The yield of cardiomyopathy gene panel testing in infants, children, and adolescents with a diagnosis of LVNC is unknown. By characterizing a pediatric population with LVNC, we sought to determine the yield of cardiomyopathy gene panel testing, distinguish the yield of testing for LVNC with or without co-occurring cardiac findings, and define additional factors influencing genetic testing yield. METHODS AND RESULTS: One hundred twenty-eight individuals diagnosed with LVNC at ≤21 years of age were identified, including 59% with idiopathic pathogenesis, 32% with familial disease, and 9% with a syndromic or metabolic diagnosis. Overall, 75 individuals had either cardiomyopathy gene panel (n=65) or known variant testing (n=10). The yield of cardiomyopathy gene panel testing was 9%. The severity of LVNC by imaging criteria was not associated with positive genetic testing, co-occurring cardiac features, pathogenesis, family history, or myocardial dysfunction. Individuals with isolated LVNC were significantly less likely to have a positive genetic testing result compared with those with LVNC and co-occurring cardiomyopathy (0% versus 12%, respectively; P<0.01). CONCLUSIONS: Genetic testing should be considered in individuals with cardiomyopathy co-occurring with LVNC. These data do not suggest an indication for cardiomyopathy gene panel testing in individuals with isolated LVNC in the absence of a family history of cardiomyopathy.

Exome Sequencing Identifies Candidate Genetic Modifiers of Syndromic and Familial Thoracic Aortic Aneurysm Severity.

Thoracic aortic aneurysm (TAA) is a genetic disease predisposing to aortic dissection. It is important to identify the genetic modifiers controlling penetrance and expressivity to improve clinical prognostication. Exome sequencing was performed in 27 subjects with syndromic or familial TAA presenting with extreme phenotypes (15 with severe TAA; 12 with mild or absent TAA). Family-based analysis of a subset of the cohort identified variants, genes, and pathways segregating with TAA severity among three families. A rare missense variant in ADCK4 (p.Arg63Trp) segregated with mild TAA in each family. Genes and pathways identified in families were further investigated in the entire cohort using the optimal unified sequence kernel association test, finding significance for the gene COL15A1 (p = 0.025) and the retina homeostasis pathway (p = 0.035). Thus, we identified candidate genetic modifiers of TAA severity by exome-based study of extreme phenotypes, which may lead to improved risk stratification and development of new medical therapies.

Natural history of aortic root dilation through young adulthood in a hypermobile Ehlers-Danlos syndrome cohort.

Hypermobile Ehlers-Danlos syndrome (hEDS) is a common inherited connective tissue disorder characterized by joint hypermobility. The natural history of aortic root dilation (AoD), a potential complication of EDS, has not been well characterized in this population. We describe the natural history of aortic root size in a large cohort of patients with hEDS. A cohort of 325 patients with HEDS was identified at Cincinnati Children's Hospital Medical Center (CCHMC), including 163 patients from a previous study. Medical records were reviewed and each participant's height, weight, and aortic dimensions from up to four echocardiograms were documented. Aortic root z-scores were calculated using two established formulas based on age (Boston or Devereux). Overall prevalence of AoD and prevalence by age were calculated and longitudinal regression was performed. The prevalence of AoD with a z-score ≥ 2.0 was 14.2% (46/325) and with a z-score of ≥3.0 was 5.5% (18/325). No significant increases in z-score were seen over time for patients with multiple echocardiograms. Participants under the age of 15 years had an average decline of 0.1 standard deviations (SDs)/year. No significant change was found after 15 of age. Between the ages of 15 and 21 years, Boston z-scores were 0.96 higher than Devereux z-scores. The nearly 1 z-score unit difference between formulas indicates caution prior to diagnosing AoD in patients with hEDS. In light of the low prevalence and lack of progression of AoD, routine echocardiograms may not be warranted for pediatric patients with hEDS.