747-4 Evaluation of Regurgitant Jets by Sound Intensity Using a Pulsatile Flow Model: Potential Contribution of Regurgitant Volume and Reynolds Number

Our goal in this study was to determine whether a new type of digital heart sound analysis method could give quantitative information about flow velocity and volume so as to allow a potentially lower-cost approach to followup studies of patients with stenotic or regurgitant valve lesions. To elucidate the relationships between hydrodynamic factors such as Reynolds number, flow velocity and flow volume and the sound characteristics of cardiac murmurs, we developed an in vitro pulsatile flow model with variable orifice size and shape (circular 0.11 cm2, 0.24 cm2, 1.77 cm2and 3.80 cm2; oval 0.24 cm2, with a ratio of major to minor axis=2; rectangular 0.24 cm2, ratio=4). Heart sounds were recorded with a new digital system (MCG) with real time spectral analysis and display and averaged over 15 “cardiac” cycles. Mean flow rate ranged from 0.6 l/min to 6 l/min. Actual instantaneous flow rate was measured using an ultrasonic flow meter for peak flow rates 1.6 l/min to 16.8 l/min. Reynolds number ranged from 6820 to 40050. For each orifice, there was an excellent relationship between total integrated sound energy (See figure: integration of intensity (I) and frequency (F) over time (T).) obtained by digital processing and Reynolds number, peak flow velocity and peak flow rate (r=0.89–0.97, 0.89–0.97, 0.93–D.99, P<0.001, respectively). The best relationship was obtained for the smallest orifice. Higher sound energies were detected for any given flow volume in asymmetrical orifices, probably due to higher turbulence. For all orifices combined, a correlation was found between peak frequency and peak velocity, but only total sound energywas correlated with peak flow rate (r=0.84, P<0.0t). Total integrated sound energy determined digitally is related to peak flow rate; peak velocity and Reynolds number parallel peak sound frequency

Testing the Children: Do Non-Genetic Health-Care Providers Differ in Their Decision to Advise Genetic Presymptomatic Testing on Minors? A Cross-Sectional Study in Five Countries in the European Union

BACKGROUND: Within Europe many guidelines exist regarding the genetic testing of minors. Predictive and presymptomatic genetic testing of minors is recommended for disorders for which medical intervention/preventive measures exist, and for which early detection improves future medical health. AIM: This study, which is part of the larger 5th EU-framework "genetic education" (GenEd) study, aimed to evaluate the self-reported responses of nongenetic health-care providers in five different EU countries (Germany, France, Sweden, the United Kingdom, and the Netherlands) when confronted with a parent requesting presymptomatic testing on a minor child for a treatable disease. METHODS: A cross-sectional study design using postal, structured scenario-based questionnaires that were sent to 8129 general practitioners (GPs) and pediatricians, between July 2004 and October 2004, addressing self-reported management of a genetic case for which early medical intervention during childhood is beneficial, involving a minor. RESULTS: Most practitioners agreed on testing the oldest child, aged 12 years (81.5% for GPs and 87.2% for pediatricians), and not testing the youngest child, aged 6 months (72.6% for GPs and 61.3% for pediatricians). After multivariate adjustment there were statistical differences between countries in recommending a genetic test for the child at the age of 8 years. Pediatricians in France (50%) and Germany (58%) would recommend a test, whereas in the United Kingdom (22%), Sweden (30%), and the Netherlands (32%) they would not. CONCLUSION: Even though presymptomatic genetic testing in minors is recommended for disorders for which medical intervention exists, EU physicians are uncertain at what age starting to do so in young children

Vascular Ehlers-Danlos Syndrome:A Comprehensive Natural History Study in a Dutch National Cohort of 142 Patients

BACKGROUND: Vascular Ehlers-Danlos syndrome (vEDS) is a rare connective tissue disorder with a high risk for arterial, bowel, and uterine rupture, caused by heterozygous pathogenic variants in COL3A1. The aim of this cohort study is to provide further insights into the natural history of vEDS and describe genotype-phenotype correlations in a Dutch multicenter cohort to optimize patient care and increase awareness of the disease. METHODS: Individuals with vEDS throughout the Netherlands were included. The phenotype was charted by retrospective analysis of molecular and clinical data, combined with a one-time physical examination. RESULTS: A total of 142 individuals (50% female) participated the study, including 46 index patients (32%). The overall median age at genetic diagnosis was 41.0 years. More than half of the index patients (54.3%) and relatives (53.1%) had a physical appearance highly suggestive of vEDS. In these individuals, major events were not more frequent (P=0.90), but occurred at a younger age (P=0.01). A major event occurred more often and at a younger age in men compared with women (P&lt;0.001 and P=0.004, respectively). Aortic aneurysms (P=0.003) and pneumothoraces (P=0.029) were more frequent in men. Aortic dissection was more frequent in individuals with a COL3A1 variant in the first quarter of the collagen helical domain (P=0.03). CONCLUSIONS: Male sex, type and location of the COL3A1 variant, and physical appearance highly suggestive of vEDS are risk factors for the occurrence and early age of onset of major events. This national multicenter cohort study of Dutch individuals with vEDS provides a valuable basis for improving guidelines for the diagnosing, follow-up, and treatment of individuals with vEDS.</p

Vascular Ehlers-Danlos Syndrome:A Comprehensive Natural History Study in a Dutch National Cohort of 142 Patients

BACKGROUND: Vascular Ehlers-Danlos syndrome (vEDS) is a rare connective tissue disorder with a high risk for arterial, bowel, and uterine rupture, caused by heterozygous pathogenic variants in COL3A1. The aim of this cohort study is to provide further insights into the natural history of vEDS and describe genotype-phenotype correlations in a Dutch multicenter cohort to optimize patient care and increase awareness of the disease. METHODS: Individuals with vEDS throughout the Netherlands were included. The phenotype was charted by retrospective analysis of molecular and clinical data, combined with a one-time physical examination. RESULTS: A total of 142 individuals (50% female) participated the study, including 46 index patients (32%). The overall median age at genetic diagnosis was 41.0 years. More than half of the index patients (54.3%) and relatives (53.1%) had a physical appearance highly suggestive of vEDS. In these individuals, major events were not more frequent (P=0.90), but occurred at a younger age (P=0.01). A major event occurred more often and at a younger age in men compared with women (P&lt;0.001 and P=0.004, respectively). Aortic aneurysms (P=0.003) and pneumothoraces (P=0.029) were more frequent in men. Aortic dissection was more frequent in individuals with a COL3A1 variant in the first quarter of the collagen helical domain (P=0.03). CONCLUSIONS: Male sex, type and location of the COL3A1 variant, and physical appearance highly suggestive of vEDS are risk factors for the occurrence and early age of onset of major events. This national multicenter cohort study of Dutch individuals with vEDS provides a valuable basis for improving guidelines for the diagnosing, follow-up, and treatment of individuals with vEDS.</p

Deficiency of knowledge of genetics and genetic tests among general practitioners, gynecologists, and pediatricians: A global problem

Purpose: The objective of this study was to assess knowledge of genetics and awareness of genetic tests among Dutch general practitioners (GPs), gynecologists (GYNs), and pediatricians (PEDs), as well as factors influencing their knowledge and awareness. Methods: An anonymous questionnaire inquiry was used, validated with a sample of 52 clinical geneticists (CGs). The study was carried out in primary care (general practice) and secondary care (general and university hospitals) in The Netherlands. A random sample of 200 GPs, 300 GYNs, and 265 PEDs received a questionnaire. In addition, all registered CGs (58) received a questionnaire for validation. In total, 122 GPs, 187 GYNs, 164 PEDs, and 52 CGs returned a completed questionnaire. The main outcome measures were differences in knowledge scores between physicians working in different disciplines and factors influencing these scores. Results: Knowledge scores of GPs (mean 64% correct answers, 61%-66% [95% confidence interval]), GYNs (mean 75% correct answers, 73%-76% [95% confidence interval]), and PEDs (mean 81% correct answers, 79%-82% [95% confidence interval]) were lower than those in the CG validation group (mean 95% correct answers, 94%-96% [95% confidence interval]). The 5th percentile of GPs, GYNs, and PEDs was at approximately 40%, 52% and 62% correct answers, respectively. There was a specific lack of knowledge about DNA testing. In addition to specialty, important factors positively associated with the knowledge scores of nongeneticists are more recent graduation, having taken an elective course in genetics, and providing genetic counseling in their own practice. Conclusion: The overall knowledge levels of genetics in many nongeneticist health care providers show clear deficiencies. This is in line with reports from other countries, showing that these deficiencies are a global problem

Preconceptional cystic fibrosis carrier screening: Opinions of general practitioners, gynecologists, and pediatricians in The Netherlands

Knowledge of the opinions of physicians with regard to preconceptional cystic fibrosis (CF) carrier screening and the possible factors that are associated with their opinions is important for the implementation of such a screening program. Data were obtained from a study in which genetic knowledge, opinions with regard to genetic testing and related skills were investigated. A questionnaire, developed and used by American researchers, was adapted to the Dutch health care situation, and sent to randomly selected general practitioners (GPs) (n = 200), gynecologists (GYNs) (n = 300), and pediatricians (PEDs) (n = 265). In this part of the study, their opinions with regard to genetic preconceptional CF carrier screening in different situations were assessed. The response rate for the GPs, GYNs, and PEDs was 64%, 69%, and 72%, respectively. In total, 63% of the GPs, 69% of the GYNs and 72% of the PEDs supported preconceptional CF carrier testing if a couple requested a test. Sixteen percent, 19% and 25%, respectively, were in favor of actively offering a test with 95% test sensitivity to all couples who were planning a pregnancy. A positive opinion on preconceptional CF carrier screening was associated with the following variables: "considering the test sensitivity as less important" (GPs, GYNs), "high perceived risk of having a child with CF" (GYNs), "providing genetic counselling in their own practice" (PEDs) and "reassurance when both partners test negative" (PEDs). Physicians are sympathetic toward preconceptional CF carrier screening if the couples themselves request a test. Physicians had reservations about routinely offering a CF carrier test

A mutation in the Kozak sequence of GATA4 hampers translation in a family with atrial septal defects

Atrial septal defect (ASD) is the most common congenital heart defect clinically characterized by an opening in the atrial septum. Mutations in GATA4, TBX5, and NKX2-5 underlie this phenotype. Here, we report on the identification of a novel -6 G>C mutation in the highly conserved Kozak sequence in the 5'UTR of GATA4 in a small family presenting with two different forms of ASD. This is the first time a mutation in the Kozak sequence has been linked to heart disease. Functional assays demonstrate reduced GATA4 translation, though the GATA4 transcript levels remain normal. This leads to a reduction of GATA4 protein level, consequently diminishing the ability of GATA4 to transactivate target genes, as demonstrated by using the GATA4-driven Nppa (ANF) promoter. In conclusion, we identified a mutation in the GATA4 Kozak sequence that likely contributes to the pathogenesis of ASD. In general, it points to the importance of accurate protein level regulation during heart development and emphasizes the need to analyze the entire transcribed region when screening for mutations

A Mutation in C2orf64 Causes Impaired Cytochrome c Oxidase Assembly and Mitochondrial Cardiomyopathy

The assembly of mitochondrial respiratory chain complex IV (cytochrome c oxidase) involves the coordinated action of several assembly chaperones. In Saccharomyces cerevisiae, at least 30 different assembly chaperones have been identified. To date, pathogenic mutations leading to a mitochondrial disorder have been identified in only seven of the corresponding human genes. One of the genes for which the relevance to human pathology is unknown is C2orf64, an ortholog of the S. cerevisiae gene PET191. This gene has previously been shown to be a complex IV assembly factor in yeast, although its exact role is still unknown. Previous research in a large cohort of complex IV deficient patients did not support an etiological role of C2orf64 in complex IV deficiency. In this report, a homozygous mutation in C2orf64 is described in two siblings affected by fatal neonatal cardiomyopathy. Pathogenicity of the mutation is supported by the results of a complementation experiment, showing that complex IV activity can be fully restored by retroviral transduction of wild-type C2orf64 in patient-derived fibroblasts. Detailed analysis of complex IV assembly intermediates in patient fibroblasts by 2D-BN PAGE revealed the accumulation of a small assembly intermediate containing subunit COX1 but not the COX2, COX4, or COX5b subunits, indicating that C2orf64 is involved in an early step of the complex IV assembly process. The results of this study demonstrate that C2orf64 is essential for human complex IV assembly and that C2orf64 mutational analysis should be considered for complex IV deficient patients, in particular those with hypertrophic cardiomyopathy